Accelerating Global Deletion of the Abnormal Toxicity Test for vaccines and biologicals. Planning common next steps. A workshop Report.

This online workshop Accelerating Global Deletion of the Abnormal Toxicity Test for vaccines and biologicals. Planning common next steps was organized on October 14th, 2021, by the Animal Free Safety Assessment Collaboration (AFSA), the Humane Society International (HSI), the European Federation of Pharmaceutical Industries and Associations (EFPIA), in collaboration with the International Alliance of Biological Standardization (IABS). The workshop saw a participation of over a hundred representatives from international organizations, pharmaceutical industries and associations, and regulatory authorities of 28 countries. Participants reported on country- and region-specific regulatory requirements and, where present, on the perspectives on the waiving and elimination of the Abnormal Toxicity Test. With AFSA, HSI, EFPIA and IABS representatives as facilitators, the participants also discussed specific country/global actions to further secure the deletion of ATT from all regulatory requirements worldwide.

Replacement, Reduction, Refinement of animal testing

Animal Free Safety Assessment Collaboration

Abnormal Toxicity Test

Center for Biologics Evaluation and research of the Federal Drug Administration, USA

Chemical Manufacturing Control

Council of Europe

Clinical Trial Application

Developing Countries Vaccine Manufacturers Network

Deoxyribonucleic Acid

Expert Committee on Biological Standardization (WHO)

European Directorate for the Quality of Medicines and HealthCare

European Federation of Pharmaceutical Industries and Associations

European Partnership for Alternative Approaches to Animal Testing

Federal State Budgetary Institution “Scientific Centre for Expert Evaluation of Medicinal Products” of the Ministry of Health of the Russian Federation

Good Manufacturing Practice

Humane Society International

Korean Institute of Toxicology

International Alliance for Biological Standardization

International Conference on Harmonization

International Coalition of Medicines Regulatory Authorities

International Conference of Drug Regulatory Authorities

Indian Pharmacopoeia Commission

International Federation of Pharmaceutical Manufacturers & Associations

International Pharmaceutical Regulators Programme

Ministry of Food and Drug Safety, South Korea

Ministry of Health, Labour, and Welfare, Japan

Minimum Requirements for Biological Products regulation, Japan

National Institute of Infectious Diseases, Japan

National Control Laboratories

General Chapter from Russian Pharmacopoeia (ОБЩАЯ ФАРМАКОПЕЙНАЯ СТАТЬЯ)

World Organization for Animal Health

Post Approval Changes

Paul Ehrlich Institute

European Pharmacopoeia

Pharmaceutical and Medical Devices Agency, Japan

Quality Control

Regulatory Authority

R&D-based Pharmaceutical Association Committee

Target Animal Batch Safety Test

Technical Report Series (WHO)

World Health Organization

Introduction

The Abnormal Toxicity Test (ATT) is a quality control test used for batch release testing; mainly by manufacturers and national control laboratories (NCLs) in different countries for biologicals, vaccines and other products. The objective is to determine whether each batch of drug product contains any unexpected contaminations. The species used are mice and guinea pigs. The ATT causes unnecessary and unethical use of animals since there is no scientific rationale as to how that test would be able to fulfil its objective of detecting contaminations.

The workshop Accelerating Global Deletion of the Abnormal Toxicity Test for vaccines and biologicals. took place on October 14th, 2021, and was organized by the Animal Free Safety Assessment Collaboration (AFSA), the Humane Society International (HSI), European Federation of Pharmaceutical Industries and Associations (EFPIA) in collaboration with the International Alliance of Biological Standardization (IABS). The workshop gathered participants of international organizations and funding bodies, industry and industrial associations, and regulatory stakeholders. The participants were invited to share their views and discuss their respective experiences in a multi-stakeholder environment.

This workshop was a followed-up to the HSI organized Symposium (Rome, 2019) [1] and on those of the IABS congress (Bangkok, 2019) [2], to maintain the momentum and further advance on the discussion on the global deletion of the ATT from regulatory requirements for human vaccines and biologicals. While a measure of success has been seen as a result of the 2019 dedicated efforts (deletion of ATT from most of the specific monographs for human vaccines from the Indian Pharmacopoeia [3]; partial deletion of ATT from NCL requirements in South Korea; additional waivers implemented in Japan), a host of other successful examples of deletions and exemptions (e.g. Europe, USA, Canada, Brazil, Argentina) [1,2], and the World Health Organization (WHO) recommendations [4,5]); a significant number of regulatory authorities (RAs) still have not changed their perspective on this test. Cooperation, information exchange and dialogue are still very much needed to assist regulators and manufacturers in evaluating and embracing change. To this end, the workshop brought together a wide range of international and local key stakeholders— including additional ones with a keen interest in vaccine innovation and increased accessibility through diminished reliance on in-vivo testing—to strategically agree on the way forward to the global deletion of ATT from the regulatory requirements for human and veterinary vaccines and biologicals.

Table 1. Status of ATT deletion in 2021.

Table 1

Status of ATT deletion in 2021.

Country	Status	Reference
USA	Deleted (2015)	Revocation of General Safety Test Regulations That Are Duplicative of Requirements in Biologics License Applications (link)
Canada	No longer required (2007)	As of 2007, requests to delete the General Safety Test (GST) for approved vaccines were accepted, and the GST was not required for new vaccine authorizations.
Europe	Fully Deleted (2019)	1998 – Deleted for batch release from >80 other monographs; complete removal from monographs for veterinary medicines, human sera and immunoglobulins, diphtheria, tetanus and pertussis vaccines and moved to the production section for other relevant human medicines.Decision taken by the EuropeanPharmacopoeia Commission during the 159th plenary session (Strasbourg on 21–22 November 2017) to delete all remaining ATT entered into force on January 1st, 2019 (link)
Argentina	Partially Deleted (2018-)	Deleted from all human vaccines. Deletion activities ongoing for other biologicals products. Revision of the Argentinian Pharmacopoeia (7th Edition, 2003) ongoing. Volume 1. Chapter: 360. ENSAYO DE TOXICIDAD ANORMAL
Brazil	Partially deleted (2019-)	Brazilian Pharmacopoeia 6th Edition (only one exception: required for monograph “Meglumine antimoniate, injectable solution”)
India	Deleted from most of the specific monographs of human vaccines (2020-)	IP 2018, Amendment List 06 of July 22nd, 2020 (link) delete ATT for all listed products (human vaccines).
South Africa	Not performed (end of 2018)	Viviani et al. (2020)
Russia	Required (waiver possibilities)	Russian Pharmacopoeia Edition XIV. OFS:1.2.4.0004.15. Abnormal Toxicity. Government Decree No. 1510 (2019) ‘On the Procedure of Batch Release of Medicinal Products for Human Use’
China	Required (waiver possibilities)	Chinese Pharmacopoeia 2020. Chapter 1141. 异常毒性检查法
Japan	Partially waived (2020)	Amendment Act (2020) of the Minimum Requirements for Biological Products (link). Waiver from some products: Influenza HA vaccine, Japanese encephalitis vaccine, Haemophilus influenzae type B (Hib), pneumococcal polysaccharide vaccine (PPSV23).
South Korea	Partially waived (2019)	Amendment to the Regulation on Approval and Review of Biologicals Products (link). Test not performed by the NCL.
Indonesia	Required	Indonesian Pharmacopoeia 6th Edition (2020). Vaksin, page 64: “Toksisitas Abnormal Memenuhi syarat Uji toksisitas abnormal seperti yang tertera pada Uji Reaktivitas secara Biologis in-vivo <251>, kecuali dinyatakan lain dalam monografi.”
Thailand	ATT deleted for all vaccines and biologicals products since WHO ECBS Recommendation (2018)	WHO 69th Expert Committee on Biological Standardization held from 29 October to 2 November 2018 (link)

Welcome and keynote speeches

The workshop opened with the welcome from the organizers, hosted by Laura Viviani (Director of Biologicals, HSI/AFSA) and Kirsty Reid (Director of Science, EFPIA), and the projection of a video retracing the history of the Abnormal Toxicity Test from its inception all the way to the time a scientific consensus was reached that acted as a cornerstone for its removal in many regulations [6].

After the projection, Dr. Thierry Gastineau (Global Quality Head of Innovation, Culture and Engagement within Sanofi Pasteur, France), and Dr. Catherine Milne (Head of the Section of Biological Standardization, International Standards for Antibiotics and Official Control Authority Batch Release, European Directorate for the Quality of Medicine and HealthCare (EDQM)) kicked off the first part of the workshop with their keynote presentations.

Dr. Gastineau focused his presentation on the global challenge of post-approval changes (PACs), especially for products authorized in many different regulatory jurisdictions. PACs are constantly needed (due to manufacturing, technological, supply and regulatory changes, or simple equipment obsolescence), however, the current fragmented regulatory landscape makes their implementation extremely onerous [[7], [8], [9]]. They need to be agreed with each national regulatory authority (RA) where a product is licensed (potentially hundreds of countries), and submitted for every product affected (i.e., multi-component vaccines). In effect, even a simple change in a component or procedure has the potential to lead to negotiations on hundreds of dossiers throughout the world, each one proceeding through specific regulations and timetables. This situation creates a huge complexity and engenders the risk of vaccine shortage, with a potential to jeopardize the timely and equitable supply to all populations.

Dr. Gastineau commended the progress achieved by the successful work by the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use.

(ICH), the activities of the International Coalition of Medicines Regulatory Authorities.

(ICMRA), the International Conference of Drug Regulatory Authorities (ICDRAs), and the International Pharmaceutical Regulators Programme (IPRP) on harmonization and the reliance principle, and WHO's recent endeavors to limit redundant activities and improve the management of PACs [10,11]. He focused in particular on the International Federation of Pharmaceutical Manufacturers & Associations (IFPMA) taskforce on COVID-19 and the first key lesson learned to reduce the regulatory burden of PACs: a) adoption of more science- and risk-based approaches; b) convergence and harmonization; c) regulatory reliance across countries; d) leveraging digital technologies to manage PACs.

The challenges Sanofi Pasteur, and other companies, faced and faces to remove ATT are proof that the lack of regulatory harmonization is a key obstacle for the industry: Dr. Gastineau noted that ATT remains in the quality control (QC) profile of multiple vaccines, that many PACs are not yet concluded (and the test is still required in many countries), that even though scientific consensus to remove the test has been reached 25 years ago and even if the test may be removed from a Pharmacopoeia, some authorities won't settle for a mere notification of its removal, demanding instead the manufacturer submits a full variation request. Therefore, while in theory some regulations allow the waiver of ATT, in practice exemptions are not always granted and require copious justifications and data.

To address this unharmonized landscape, and facilitate the production and release of vaccines, Dr. Gastineau proposed an adaptation of the 3Rs to better recognize the regulatory process, dubbing it 4Rs. This adaptation is characterized by:

Reduce: the number of PACs reported, if companies can demonstrate robust quality systems; the timing for review and approval of PACs, committing to comply with those timelines; in-vivo testing.

Refine: regulatory processes, moving towards alignment, convergence, harmonization of requirements and procedures, globally; transparent communication of the procedures in place.

Replace: National procedures by collaborative ones; in-vivo by in-vitro testing.

Reliance, a 4th R: authorities in the world do make reference and rely upon what has been already accepted or reviewed and accepted by other authorities in the world. So reliance on reference authorities for accelerating the review (if needed) and approval of PACs, and apply the same principles to batch release activities.

Dr. Milne's presentation focused on the ATT, the scientific endeavors that demonstrated its inadequacies, the subsequent steps that led to its removal from the European Pharmacopoeia (Ph. Eur.), and on Europe's effort to implement the removal of other obsolete tests.

The mouse test was initially developed as a safety test in the 1890s to detect toxic levels of phenol in sera. Later the 1900s a guinea pig test was established as an indicator of extraneous clostridial toxins in sera and vaccines. ATT took its current form only in the 1940s, when the two tests were combined. In this form, it eventually found its way into almost all general testing requirements for immunological and biological medicines around the world, surviving practically unchanged up to 2021 despite significant evolution in manufacturing and analytical techniques.

Beginning in the 1990s, the ATT was a target for replacement, however there were significant challenges to apply this. Replacing ATT with alternatives was not feasible, as neither the purpose nor validation parameters of the ATT were clearly defined; removing it faced significant resistance from regulators and QC experts, who saw its removal as a risk not sufficiently offset by the removal of a test of comparatively limited severity and only requiring small numbers of animals. To proceed further, a significant effort and convincing supportive data, were needed. This came in the form of a seminal retrospective analysis performed by the Paul Ehrlich Institute (PEI) in 1994–5 [12], which finally demonstrated that ATT is neither specific, reproducible, reliable, nor suitable for the intended purpose, and that more relevant tests are available for testing phenols, and toxins, and other affected materials. In addition, the effective deployment of GMPs and strict aseptic QC measures to prevent contamination clearly called the relevance of ATT into question.

Based on this evidence a request to delete ATT from the Ph. Eur. came in 1995 [[12], [13], [14], [15]]. It was also motivated by increased social sensitivity to animal welfare, to which Europe has a long tradition of attention. Dr. Milne summarized through key milestones like the Council of Europe (COE)'s 1986 European Convention for the Protection of Vertebrate Animals used for Experimental and Other Scientific Purposes [16], the establishment in 1991of the EDQM Biological Standardization Programme co-sponsored by the COE and the EU Commission and all the way to the Directive 2010/63/EU [17].

In 1998, a decision was taken to delete ATT as a batch release test in over 80 monographs. with complete deletion for veterinary products, human sera and immunoglobulins and diphtheria, tetanus and pertussis vaccines, and a move to the production section for the remaining human products. A further move toward the complete deletion of ATT came during the European Partnership for Alternative Approaches to Animal Testing (EPAA) Workshop in 2015 [18], when a host of global stakeholders agreed that the test lacks scientific relevance, that its omission does not compromise the safety of biologics, and that it should be deleted from regulatory requirements at the global level. After a detailed evaluation of all remaining monographs containing reference to ATT the Ph. Eur. Commission decided to delete ATT from all 49 remaining monographs, which led to the publication of the revised monographs with no reference to the test, and the suppression of the general chapter 2.6.9 (Abnormal Toxicity Test) in 2018, thus signaling the end of ATT in the Ph. Eur. starting from January 2019. Europe's success in the elimination of the test, and EDQM's persistent presentation of results, helped the Expert Committee for Biological Standardization (ECBS) of WHO to agree to publish, in 2018, its recommendation to discontinue the test from WHO guidelines, and that the inclusion of the test (ATT) in previously published WHO TRS documents be disregarded [4].

The process of deleting ATT's sibling test, the Target Animal Safety Batch Test (TABST) [19], which required testing the innocuity of inactivated or live veterinary vaccines by administering an overdose in the target species for each batch, began in 2004 by allowing waivers for established vaccines. After an extensive review by Ph. Eur. experts in 2012 the TABST was completely removed from the Ph. Eur. in 2013.

Dr. Milne stressed that the EDQM, the Ph. Eur. Commission, its experts and stakeholders are committed to applying good science and the 3R principles in the Ph. Eur. texts. This includes the removal of obsolete tests such as ATT (the “fourth R″, as per Dr. Milne) and facilitating use of the 3Rs, through the Ph. Eur. General Notices and General monograph for vaccines for human use (0153) by including example methods when available and “door openers” in various monographs and in the absence of a common description of an in-vitro model, authorities are still encouraged to consider appropriately validated in-vitro alternatives. Another key tool is the recent (2018) general chapter 5.2.14 – Substitution of in-vivo methods by in vitro methods for the quality control of vaccines, which details the concept of “substitution” of animal tests for the quality control of vaccines. It specifically highlights the challenges for direct replacement of existing in-vivo methods, linked to the lack of formal validation data and inherent variability of the historic in-vivo methods and the fact that direct 1:1 substitution is often not possible, and may require not a single, but rather a combination of in-vitro tests. It also provides examples and potential approaches to overcome this.

Work has already been performed to re-evaluate the need for historic tests in the current scientific context. Some of this work has already been finalized [20], i.e.:

Histamine sensitization test (HST) in mice: For acellular pertussis vaccines, the test for residual toxin formerly done by HST on the final lot, is replaced by a standardized cell-based (CHO) assay [21] on the non-adsorbed purified pertussis components, and the test for irreversibility of toxoid test on final lot is deleted, effective 01/01/2020.

Toxicity for Tetanus vaccines: with the removal of the specific toxicity during process validation and the test and irreversibility of toxoid on guinea pigs on final lots, the residual toxin test in guinea pig is retained only on bulk purified toxoid, effective 01/01/2021

Toxicity for Diphtheria vaccines: removal of the guinea pig-based specific toxicity test during process validation. Residual toxicity is assessed by a Vero cell assay, on bulk purified toxoid, effective 01/01/2022.

Roundtable: Global perspectives on ATT deletion

After the presentations of Drs. Gastineau and Milne, the workshop opened to a roundtable discussion titled Global perspectives on ATT deletion. It was chaired by Dr. Shahjahan Shaid, Program Manager and Head of 3R, GlaxoSmithKline (GSK), Germany, with the participation of representatives from EFPIA, the Developing Countries Vaccine Manufacturers Network (DCVMN), WHO, Health Canada, the Center for Biologics Evaluation and Research (CBER) of the Food and Drug Administration (FDA) of the United States of America, and the Bill and Melinda Gates Foundation.

The first point discussed by the participants of the roundtable was related to ensuring safety in the absence of the ATT. More specifically, it was focused on whether endotoxin, pyrogen and sterility tests may be sufficient to evaluate the safety of biological products if ATT is eliminated from safety testing? The question came from the audience, and raised the issue that other tests which are mentioned in regulations and pharmacopoeias – including the WHO Technical Report Series and International Pharmacopoeia – may not provide the biological response presented by ATT.

Various speakers addressed this issue. Dr. Dean Smith, from Health Canada, noted that reliance on non-specific “black box” tests such as the ATT is not supported by science [[19], [22]]. Modern control test strategies begin with the qualified raw materials and continue with testing through each stage of production to the end of product's shelf-life. As an example of the lack of relevance of ATT as a safety test, Dr. Smith cited a relatively recent case (2008) [23] in which deliberately adulterated heparin products were allowed on the market having passed all the required tests, including the ATT. This resulted in patient deaths and recalls of adulterated lots, based the implementation of more sophisticated tests.

Dr. Dianliang Lei, from WHO, explained that since 2000, WHO has changed its stance towards ATT when proper GMPs are implemented and consistency of production ensured. After a thorough review of literature, the ECBS recommended to remove ATT from WHO's technical documentation, and to disregard it in those cases in which it is required [4,5]. Dr. Lei also pointed out that ATT is still a requirement for many RAs, and that multilateral discussions with regulators and manufacturers ought to be carried out to ensure the harmonization and convergence of regulations in different parts of the world.

Reflecting on the elimination of ATT and global harmonization, the moderator asked Dr. Lei whether a shift is taking place not to test COVID-19 vaccines with ATT, as there are many products from a variety of manufacturers being distributed in so many countries in the world in such a short time, and on the rationale for the shift.

Dr. Lei responded reminding that GMP, in addition with comprehensive validation of manufacturing processes, and sophisticate control for starting materials means less and less introduction of any toxic components into the manufacturing processes, so removing ATT is unlikely to compromise of the quality and safety of the product. But he also indicated that its removal is certainly beneficial to the timeline as ATT takes time (about 7 days) to perform. As to the COVID-19 specific question, he explained that WHO recommends all the countries without full capacity to perform the needed tests on COVID-19 vaccines, to rely on the marketing authorization and the batch release of the exporting countries.

As a significant number of COVID-19 vaccines are being developed in the USA, the moderator asked Dr. Robin Levis, from CBER/FDA, about the situation in the country. Dr. Levis clarified that the requirement of ATT was removed from the Code of Federal Regulations in 2015. Therefore, the USA regulatory authority did not require ATT from any COVID-19 vaccine manufacturers. When a manufacturer submits a development program which includes ATT, the authority clarifies that the test is not needed. She acknowledged though that, some manufacturers had been required to assess products’ toxicity in the preclinical phase as a part of product development, to establish and characterize the safety of the product along with the manufacturing process.

Dr. Gautam Sanyal from Vaccines Analytics (USA), who participated on behalf of the Bill and Melinda Gates Foundation, asked if there was evidence from manufacturers on whether regulatory agencies of receiving countries, which require ATT for batch release, made exceptions for COVID-19 vaccines that were released by manufacturerswithout ATT. If they did, this could be a powerful precedent, at least, for pandemic vaccines. An answer to this question was provided by Dr. Mark van Ooij, from Janssen Vaccine Technology, who stated that while most countries are not requiring ATT, some still are, especially for COVID-19 vaccines produced using the new technology platforms. Manufacturers are in negotiations with these NRAs and hope to be able to convince at least some of them to agree on granting a waiver if a certain number of batches passed ATT. However, Dr. Smith pointed out that success in securing ATT waiver is incumbent upon pharmacopoeias reviewing the evidence that demonstrates the absence of scientific relevance of the ATT. Dr. Smith also commented that authorities which support the EDQM have invested the time and resources to understand this issue. This resulted in the deletion of the ATT from the Ph. Eur. Additionally, it should be expected of any competent authority to reduce the regulatory burden on industry, which results from requiring ineffective tests.

The next topic addressed during the roundtable concerned adverse events following the vaccination, specifically on other parameters to consider for safety, and how to ensure the vaccine is safe.

Dr. Levis expressed the conviction that ATT is not an appropriate test. To address safety issues, pharmacovigilance guidelines suggest that product-related, post-licensure follow up should concentrate on the specific features of the manufacturing process and its associated impacts, taken into considerations both the clinical aspects of the adverse events and potential product impact. She referred to the adulterated heparin case reported by Dr. Smith as further proof that ATT is not a valid instrument for adverse events investigations.

A question was raised regarding any observed increase in adverse events, since the elimination of the ATT? Dr. Smith replied that there was no such observation, and again emphasized that the notion that an outdate test such as the ATT could provide any meaningful measure of product quality had no scientific basis. Dr. Smith did acknowledge that keeping up with the technical advances involved with more relevant QC mythologies may be a challenge for under resourced authorities. However, this should not be a rationale to maintain the ATT. A better approach to meet the challenge concerning the implementation of advanced technologies is for authorities to work collaboratively on a regional basis. Such willingness to look beyond national borders and pharmacopoeias is needed. This approach will benefit the authorities, the populations they serve, as well as manufacturers.

Dr. Philippe-Alexandre Gilbert, of the Bill & Melinda Gates Foundation, chimed in, with further comments on the need for harmonization. First, he stated, it is of great importance to not set developing countries up for failure by having them inherit methods that make little sense in the local conditions. Also, it is essential that a “fourth R” - meaning removal – is considered and that efforts should be made not only to the standardization of methods, but also, critically, to a standardization of methods removal. The removal of the ATT, in all its importance, should represent the tip of the iceberg of a wider effort.

The process of elimination of ATT has been shown to be complex even when regulatory authorities are open to that kind of change. Dr. Leena Madhuri, Quality Control Lead of Indian Immunologicals representing DCVMN, commented that in India, because a general chapter in the national pharmacopoeia states that if a lot is tested by a National Control Laboratory (NCL) the test should pass; therefore, manufacturers do still perform ATT to ensure that there will be no test failure. The Indian case raised the question of whether channels for dialogue exist between manufacturers and RAs and if it is sufficient. Dr. Shaid, shared the experience of GSK: the manufacturer held talks with regulators, trying to convince them to accept waivers after data and tests have been performed, but they never received a guarantee of agreement. This example further highlights the challenge of harmonization.

The topic of RAs deleting or accepting waivers to ATT was further debated based on a direct question coming from the audience: in light of the scientific consensus on ATT, by which rationale do certain countries hold on to ATT, and what would convince them to delete it?

Dr. Smith restated the absence of scientific rationale to perform ATT and mentioned that reasons other than scientific are often in place. To this end, Dr. Smith suggested a possible follow up action on the transition away from ATT: increase the involvement of the ICMRA. ICMRA could prove a very useful discussion venue to highlight the irrelevance of the test, its burden, and its impeding of lot release. The dialogue would be enhanced, especially if manufacturers will be involved.

On the point of delays and time consumed by ATT, Dr. Van Ooij added that, for a manufacturer, the time needed for ATT does not restrain the execution of the test at lot release. Rather, in order to pass ATT, it is time-consuming to generate country-specific pre-test results and having national RA re-perform to confirm the data. This phenomenon, again, is due to the lack of harmonization across countries on the specifics for ATT methods. This leads to an entire chain of actions which requires expenditure of significant numbers of animals and time with no added scientific value. Dr. Van Ooij remarked that the elimination of ATT by two large entities, Europe and USA, is also benefitting the dialogue between the manufacturers and those RAs which still require ATT, in a sort of positive, snowballing effect.

In closing the roundtable, a series of final statements were collected from the participants.

Dr. Gilbert pointed out the importance of exchanging information for the removal of the test, highlighting the necessity of collaboration and networking, pointing out as an example to the DCVMN.

Dr. Madhuri acknowledge that manufacturers do look forward to the deletion of ATT, and she thinks it is important that such deletion takes place under the umbrella of the consistency approach, to ensure the highest quality.

Dr. Lei confirmed again WHO's clear position on the removal of ATT from lot release testing, and expressed the opinion that dialogues will be needed to implement the ECBS recommendation, thinking favorably of the involvement of ICMRA and of WHO engaging with member states to implement the recommendation into their regulatory practices.

Dr. Shaid stressed the importance of multi-stakeholder dialogue and coordinated actions to seek global harmonization since as long as there's a loophole, ATT will still remain in place one way or the other.

Open session: Many countries many approaches, how far are we for a global alignment

After the roundtable, the workshop moved to the open session titled Many countries many approaches, how far are we for a global alignment, which was chaired by Dr. Joris Vandeputte, President of IABS, with the participation of panelists from Japan, China, Russia, India, Indonesia and South Korea.

Introducing the open session, Dr. Vandeputte recalled the 2019 conference in Bangkok [2], organized by IABS and HSI in collaboration with the Thailand authorities, which was well received by the Asian colleagues and signaled significant interest exists on exchanging and participating.

The first panelist to speak was Dr. Takuo Mizukami, Laboratory Director of Japan's National Institute of Infectious Diseases (NIID). Dr. Mizukami reported on the status of ATT in Japan: testing by both manufacturers and the NIID is required for inactivated vaccines, while for live attenuated vaccines execution of ATT is required only from the manufacturer. An average of 250 lots are released per year in the country, with more than 500 ATTs performed, resulting in the use of approximately 1000 guinea pigs.

Since 2008 an exemption to ATT is considered for vaccines not derived from live viruses or bacteria. For the recombinant Hepatitis B vaccine, a waiver rule first introduced when analysis of data showed 20 consecutive lots to have tested successfully for ATT. After 2013, historical data of other vaccines were evaluated, leading to the waiver of ATT for a series of other vaccines (Influenza HA vaccine, Hemophilus influenza type B (Hib), Japanese encephalitis, Pneumococcal polysaccharide vaccine (PPSV23)). In 2020 the Amendment Act has been enforced, granting waiver of ATT for about 70–80% of vaccine lot release. Review of the historical data of recombinant vaccines (such as Human Papilloma Virus and conjugated vaccines) is ongoing to introduce similar waivers. For live attenuated vaccines, manufacturers’ test results were reviewed in-house: this review did show that no batch had failed the test, supporting that ATT is no longer needed to determine safety and consistency of this type of vaccines. Further communications are planned with the manufacturers, to waive all ATT requirements for live attenuated vaccines by 2022.

Regarding blood products: over 400 batches of products are released in Japan per year. Similarly to vaccines, the ATT is performed predominantly by manufacturers, although independent testing by NIID had been already waived since 2005. In 2020, NIID reviewed 20 years of historical manufacturing data, and found no failure of ATT, which provided further evidence that ATT is not needed to ensure safety and consistency for the blood products. As a consequence of this review, ATT is anticipated to be waived on 21st October 2021for all blood products. Work is ongoing to delete the requirement for ATT for all the vaccines in the following years.

Dr. Yoshihisa Shirasaki, Manager in the CMC RA, Regulatory Affairs of GlaxoSmithKline, Japan continued the discussion initiated by Dr. Mizukami. Dr. Shirasaki explained that ATT is defined as a general test in the Japanese Minimum Requirements for Biological Products (MRBP). During the submission of a new vaccine to the authorities, the NIID has the authority to require the execution of ATT as a QC test even if the manufacturer did not set ATT as a specification. Also, each vaccine must conform to a monograph in the MRBP, and in most cases, those monographs still include ATT.

Dr. Shirasaki proceeded then to describe the communication between manufacturers and regulatory authorities in Japan, with regards to the elimination of ATT. Initiated by manufacturers and including national pharmaceutical and vaccines producers associations, the Japan Vaccine Industry Consortium is currently considering the elimination of ATT from the MRBP with the Ministry of Health, Labour, and Welfare (MHLW), the NIID, and the Pharmaceutical and Medical Devices Agency (PMDA). This has been facilitated by workshops held in the last four years. The Japan Vaccine Industry Consortium considers ATT no longer needed, since GMP manufacturing process has been implemented for several decades in Japan, and the process production consistency is confirmed by raw material control, process validation, in process testing and QC release testing. Dr. Shirasaki concluded on the activity of the MHLW, which is working towards alignment on leading international standards, hoping this will expedite procedures for manufacturers and expedite the abolition of the ATT.

Focusing on China, the next panel speaker was Dr. Jianxun Xie, Head of Preclinical Sciences and Translational Safety China at Janssen China. Dr. Xie introduced the R&D-based Pharmaceutical Association Committee (RDPAC), which comprises 42 multinational companies with R&D capacity in China, and has been very active in engaging Chinese authorities.

In China, ATT is required for all biologics and vaccines, for registration and lot release. In case of vaccines, some of them – like the COVID-19 vaccine and several others – require ATT at the Clinical Trial Application (CTA) stage or sometimes before the first in-human stage. According to China Health Authority's requirements, the ATT must be performed with both mice and guinea pig. Significant progress has been achieved with the 2020 Pharmacopoeia after much effort from RDPAC members: the Pharmacopoeia states that if the quality of the product, or its attributes, cannot be suitably measured by ATT, then the test can be waived based on an approved solid rationale and successful risk assessment [24]. Despite this regulatory progress, Dr. Xie, commented, it is still difficult for manufacturers to produce the appropriate justifications and receive waivers according to the pharmacopoeia.

Dr. Xie handed the floor to Dr. Xiantang Li, Senior Director DSRD, Asia Lead, Pfizer, to further describe the Chinese regulatory landscape.

Dr. Li recalled the significant joint work performed by DruSafe and RDPAC to engage the Pharmacopoeia Committee in 2018 and 2019, to secure a deletion of ATT. The group shared with the Committee publications [25] justifying the deletion of ATT, including the EFPIA white paper from 2017 [26,27] and WHO recommendations [4]. Dr. Li agree with Dr. Xie that, unfortunately, waivers for ATT will remain difficult to justify in the absence of clear regulatory guidance. Still, Dr. Li concluded, dialogue between RDPAC and the Pharmacopoeia Committee will certainly continue, aiming for a deletion of ATT from the 2025 pharmacopoeia.

Next, Dr. Ying-Ying Zhou, Senior Principal Scientist in the Nonclinical Drug Safety Department at Merck Research Laboratories, USA spoke. Dr. Zhou completed the depiction of the landscape of the Chinese pharmaceutical sector by explaining that the country has embarked on a colossal goal, Healthy China 2023, that aims to transform its healthcare system. As such, there is significant transformation taking place, and much reform and evolution of regulatory policies, with literally hundreds of new guidelines produced in the last few years, and many companies emerging. This transformative environment is accelerating the drug development and clinical trials for the approval of new products. It is also making the field more heterogeneous. On one side, the big pharmaceutical companies have significant CMC capacity, and on the other side, smaller companies have more limited budgets and resources to maintain a consistent safety control process and GMP reliance on the other. This heterogenicity is probably the reason, according to Dr. Zhou, why the current policy aims at finding a balance with regards to the elimination of ATT: the authority offers a way for bigger companies to waive the test, but maintains the test for smaller players which might experience compliance issues. She states that to proceed further towards the elimination of the test, RDPAC intends to maintain an active dialogue and interaction with the national regulatory agency. Hopefully, the goal of deleting ATT could be be achieved by the publication of the next Pharmacopoeia edition.

From China, the discussion moved to Russia, with Dr. Alla Trapkova, Deputy General Director of the Federal State Budgetary Institution ‘Scientific Centre for Expert Evaluation of Medicinal Products’ of the Ministry of Health, Russian Federation. Dr. Trapkova explained that ATT is included in both the XIV edition of the Russian Pharmacopoeia (in a variety of monographs, like Active Pharmaceutical Ingredients (OFS.1.1.0006.15), Parenterals (OFS.1.4.1.0007.15), Recombinant DNA Medicinal Products (OFS 1.7.1.0007.15), Allergens (OFS.1.7.1.0001.15), Bacteriophages (OFS.1.7.1.0002.15), Vaccines and Toxoids (OFS.1.7.1.0004.15), Immunobiologicals (OFS 1.8.1.0002.15), Human Immunoglobulins (OFS 1.8.1.0003.15), and Heterologous Immunoglobulins and Sera (Antibodies) (OFS 1.8.1.0004.15)), and also in the Volume 1 of the new Eurasian Pharmacopoeia. The Russian version of the test differs from the European and American versions, as it prescribes the injection be carried out in only 5 s. Experience demonstrated that the slower injection method was incapable of detecting toxic effects from products such as antibiotics of natural origin.

However, Dr. Trapkova confirmed that the removal of the ATT is on the agenda both of the Russian and of the Eurasian pharmacopoeias [28], and that scientific recommendations for the removal of the test have been published for a series of products (water and saline injection packages under 50 ml; orphan medicinal products; local anesthetics). Discussion is currently ongoing for two other products: monoclonal antibodies for subcutaneous administration, and insulin and its analogues.

Out of 114 vaccines licensed in Russia, Dr. Trapkova explained that 54 were available on the market in 2020, and 48 of them was required to be checked for abnormal toxicity. She also added that since 2012, no biological product has failed ATT. And yet, she added, deletion of ATT cannot be arbitrary: it needs to rest on a series of conditions: manufacturers GMP compliance, validation of processes, adequate control over product and formulation stability; including active pharmaceutical ingredients (API) procurement from well-established certified suppliers.

Dr. Trapkova informed the participants that the decision to remove ATT from a product specification is currently taken on a case-by-case basis for every medicinal product, but that for many such products the test has already been removed from routine batch release testing.

As to the reason why the Russian regulatory authority maintains the test in the QC system, Dr. Trapkova explained that the test should be able to indicate when medicinal products are not compliant with pharmacopoeial requirements in terms of toxicity. As an example, data from national control laboratories show that ATT has been widely used and often failed in the last 5 years for cephalosporine antibiotics.

Concluding, Dr. Trapkova summarized Russia's approach to the replacement of animal testing with in-vitro alternatives: Russia is working in the direction of replacing animal use and phasing out ATT for some types of medicinal products.

With Dr. Sunil Kumar Goel, Additional Director QC, Serum Institute, the discussion shifted to India. First of all, Dr. Goel informed that ATT has been deleted from human vaccine monographs of the Indian Pharmacopoeia with an amendment published in July 2020 [3]. The deletion of ATT took its first steps in India in 2015 when Indian vaccine manufacturers engaged the national RA and the Indian Pharmacopoeia Commission (IPC) and put forth a request for ATT deletion and for waivers of other tests. This led to a series of joint meetings between the national RA, IPC and the manufacturers. In 2018, IPC produced a revision of the Pharmacopoeia in which ATT was waved conditionally (condition: manufacturer to demonstrate consistency of production to the satisfaction of the National RA and GMP is in place). Despite this significant step, he explained, local vaccine manufacturers (about 20) were aiming higher, keeping the discussion ongoing, and had submitted substantial amounts of data, comments to monographs, and information collated from worldwide pharmacopoeial discussions. These continued efforts led to the July 2020 amendment in which ATT is deleted from almost all human vaccines.

It was highlighted by Dr. Goel that the manufacturers were supported by the IPC and the goal was reached together. Work and discussions are ongoing to implement the deletion of other tests. Lastly, Dr. Goel commented that the removal of ATT in one country still does not mean a manufacturer can be free from performing it: the manufacturer will have to perform the ATT if the importers require.

Dr. Jai Prakash, Senior Principal Scientific Officer, Indian Pharmacopoeia Commission, India, further gave inside details on the process of ATT removal from the Indian pharmacopoeia. The decision to delete ATT was taken with specific conditions for routine batch release: 1) consistency of production must be established to the satisfaction of NR; 2) GMPs need be properly in place; 3) each batch, if tested, should pass the ATT when performed by the NCL.

He added that work is ongoing on TABST. Following the Humane Society International workshop on TABST and LABST in February 2021, the IPC requested retrospective data on batches from the manufacturers and requested the manufactures submit a clear proposal for the elimination of those tests. In general, Dr. Prakash made it clear that the IPC tries for harmonization of vaccine standard, and is also sensitive to the request of manufacturers for changes in standards, but it also sensitive to a proper evaluation (that is: applicability in the Indian context) of proposed modifications, before change is considered for consideration in the Indian Pharmacopoeia.

After Dr. Prakash, Dr. Amrullah Aninditio Subagio, Quality Control Division, Biofarma Indonesia, took the floor to discuss the landscape of deleting ATT in Indonesia. Dr. Subagio explained that, manufacturers carry out intensive communication on requesting harmonization with the National Control Laboratory and National Regulatory Authority. One of the topics in the discussion is whether the sterility test, endotoxin test, and pyrogen test, either by itself or in combination with each other, are sufficient to replace ATT, and whether the elimination of ATT will be abrupt, or if it will be carried out gradually. The manufacturers are well aware that the elimination of ATT will help them reduce testing and shorten time needed for vaccine release. Dr. Eniek Suwarni, of the Indonesia Food and Drug Administration, spoke next, sharing the regulatory perspective on deleting ATT.

Dr. Suwarni explained that ATT is performed on all vaccines, so are the Endotoxin and Sterility tests. Dr. Suwarni clarified that a proposal has originated from the Indonesian FDA to eliminate ATT from the national pharmacopoeia. The removal will depend on a series of codfnsiderations: a) based on the development of science, some organizations, such as WHO ECBS and the EDQM have eliminated ATT for final products; British Pharmacopoeia 2021 and European Phamacopoeia 10th have deleted ATT for vaccines and biological b) an analysis of ATT showed that ATT doesn't seem to be relevant in the identification of a dangerous batch of final products; c) 3Rs Principle (Replacement, Reduction, Refinement) should be considered when determining if ATT is necessary.

However, Dr. Suwarni shared that some countries which rely on WHO guidance for vaccine safety are still convinced ATT is important as a safety parameter and they have delayed the deletion of ATT since ATT has not been concretely deleted from WHO Technical Report Series.

Next the discussion moved to South Korea, with Dr. Kyung Jin Jung, a research scientist of the Korean Institute of Toxicology. Dr. Jung spoke on the status of ATT regulation in Korea, explaining that ATT testing has not yet been removed for most of the biologicals that are subject to regulation on Approval and Review of Biological Products. According to the cited Korean regulation, ATT testing can be waived in case of data confirmed by an advisory person in charge of quality control at the manufacturer, if said data proves that the lot was produced in compliance with quality control and external contamination in the manufacturing process is absent.

As per the declaration of the Ministry of Food and Drug Safety, and excluding national lot release materials, ATT is still being requested by regulatory authorities for the approval of biological products. While no waiver has been recorded in the past five years, the Ministry is preparing a review of the ATT requirements. Also, in 2019, regulatory authorities amended the ATT requirements for biologicals, which deleted ATT testing requirement from the NCL testing. As a response to the COVID-19 emergency, four vaccines (Moderna, Pfizer, Janssen, and AstraZeneca) were exempted from ATT testing after a final quality check.

Dr. Jung also informed the audience that South Korean authorities are committed to further revise the requirement of ATT testing already in 2021, contemplating the deletion of the test, although the process could take more time than anticipated due to the many bureaucratic activities involved the process could take more time than anticipated.

After Dr. Jung, a series of questions from the audience was discussed with the panelists.

Three questions were specifically directed to Dr. Trapkova: 1) whether a company may file an application in Russia for an ATT waiver for a monoclonal antibody for subcutaneous administration (with a therapeutic dose of less than 3 mL), which received an affirmative answer; 2) how can the use of ATT solve the problem with substandard antibiotics and other products, to which Dr. Trapkova answered that ATT cannot solve the problem of substandard medicines – something that can be solved by careful implementation of GMPs by manufacturers – but based on the Russian experience ATT can prevent substandard antibiotics from entering the Russian market; 3) what tests are required to check the safety of a vaccine for which adverse reactions are reported, with Dr. Trapkova explaining that if adverse reactions are reported for a vaccine, samples of this vaccine batch will be tested by an official quality control laboratory for all the test parameters included in the product specification.

A subsequent question concerned the removal of ATT testing from Indian Pharmacopoeia: whether ATT has been removed entirely, or whether it is just waived if a certain set of data are provided, and if so what data is needed. Dr. Prakash answered clarifying that, as per the Indian pharmacopoeia, specifies all vaccines need undergo ATT unless otherwise stated. While the test in mice may be inappropriate for vaccines containing phenol as preservative, ATT may be omitted for routine lot release once the consistency in production has been well established to satisfy the national regulatory authority, GMPs are in place, and each batch tested by the NCL has passed the test on the abnormal toxicity.

Next came a more general question to the WHO: would the WHO embark more directly, maybe through a workshop or other activities, to foster global harmonization and removal of ATT, given the political weight it would carry as an institution?

Dr. Lei answered reminding that WHO's role is consultive, and that it is the responsibility of national RAs to implement changes into national pharmacopoeias, and that key to its recommendation to remove ATT is the implementation of GMPs, validation of manufacturing processes, QC to ascertain process control and final product control, and control of source materials. So, Dr. Lei stated, WHO is open to assist member states with regulatory/scientific issues, if they express the need. And also, Dr. Lei agreed with the previously expressed suggestion of leveraging ICMRA bi-annual meetings as venues for discussion and consensus building.

Another question concerned adverse events following immunization (AEFI), specifically what kind of tests should be carried out to ensure the safety of the vaccine in the investigation of adverse events?

Dr. Lei answered that within WHO there is a group working on AEFI, and that WHO publishes a memoir detailing procedures that should be followed after an adverse event, especially focused on how to perform the causality investigation [29]. Laboratory testing the quality of vaccines, Dr. Lei explained, is only one procedure of a very long list (and possibly the least important) that needs be implemented during causality investigation. Dr. Das chimed in, explaining that if adverse reactions are happening, neither using mice or guinea pigs makes sense to investigate them because they will not produce the same reactions as humans. As such, he continued, performing ATT is not the whole investigation, rather it's the national RA or the WHO to follow the whole process to understand what the issue might have been.

On adverse events, an answer came also regarding Russia, explaining that in case of adverse effects recorded, samples of the batch of vaccines are sent to an official laboratory for testing.

Collaborative session: defining next steps

After the open session, the workshop moved to its last item of the agenda, the collaborative session to define the next steps. The session was moderated by Dr. Vaugh Kubiak, IABS consultant. Dr. Kubiak opened the session by polling the audience for the consensus on the lack of scientific value of ATT, and asked whether participants still had lingering convictions for the need of ATT.

The first comment came from Dr. Octavio Presgrave, from Brazil's Center for Validation of Alternative Methods (BraCVAM). Dr. Presgrave shared a positive example of changing attitude towards ATT, which is now considered devoid of value: after reviewing data from the last 15–20 years, instances of ATT failure was not found [30]. Also, the analysis convinced them that the belief that 2 or 5 guinea pigs and five mice could prove the existence of toxicity with any statistical significance is unjustified.

Dr. Pradip Das agreed on the view of deleting ATT, sharing his experience of 16 years without a single ATT failure, and commented that the intraperitoneal nature of the injection offers no justification to evaluate toxicity. He also commented on the lack of utility of ATT as a batch release test, as it is very possible that a batch may fail in sterility test however the subject batch may pass in ATT test, hence ATT test is not a reliable test to assesses safety of the product and can be omitted from batch release and stability testing.

Dr. Patricia Aprea from the National Administration of Drugs, Foods and Medical Devices (ANMAT), Argentina, added that the ATT requirement was deleted from the pharmacopoeia for the marketing authorization and batch release in Argentina. In a survey ANMAT performed in 2018/2019, some companies raised the problem of eliminating the test from their specifications since it was a requirement in the importing countries. Other companies mentioned that it was a historical requirement in their specifications, but committed to eliminate it. As of today, all companies have eliminated the assay from their specifications, communicating this as a post-marketing authorization variation. She stressed that both dialogue with Argentinian companies, and the elimination of the European requirement of carrying out the test for foreign companies were of great importance for the deletion of ATT as reported.

The discussion moved to the issue of regulatory decisions to waive or remove ATT, with a specific question on imports: do those countries that waived ATT for their in-country manufacturers still require ATT testing for imported products? Further, the question was expanded to whether RAs perform ATT testing on imported vaccine batches even if the ATT is not performed by the manufacturer?

Dr. Xie supplied information on China: authorities will perform ATT on batches before release. If issues arise with the test, the authority will engage the manufacturer to ascertain whether the results of the test were caused by some of the components of the product, or whether they were caused by contamination. If the manufacturer can convincingly show that the cause for test failure is related to components, then the batch can be retested. For certain vaccines, like the innovative COVID-19 vaccines, some modifications, based on exploratory testing, may be made to the test to avoid its failure in absence of contamination. Dr. Trapkova clarified the Russian status on import: she explained that each batch of an imported vaccine undergoes testing by a Russian official quality control laboratory for batch release, but that the required scope of testing of each product – which may include ATT – is determined by the Commission for Vaccine Quality of the Federal Service for Surveillance in Healthcare (Roszdravnadzor).

Dr. Kubiak brought back the discussion on how harmonization can be further promoted and on what opportunities are already present that could help local programs move forward to achieve a successful global elimination. The role of international organizations like the World Organisation for Animal Health (OIE), WHO, and ICMRA for example, have been brought up again in the discussion as key influencers in facilitating global discussion with possible local impact where technical, scientific and policy discussions can be facilitated together with access to data and experiences.

Laura Viviani, Director of Biologicals at HSI, added that since the 2015 EPAA workshop – already mentioned by Dr Milne in her presentation – all the publications on the deletion of ATT have been shared with all relevant regulatory and industry's stakeholders, but that sharing product specific batch release data will not be possible. However, sharing what type of data are analyzed or submitted has been considered useful at a local level and has helped local industry and regulatory stakeholders to initiate a dialogue and kickstart concrete work towards the deletion of ATT. All the country-specific experiences reported so far during the workshop are good examples of dialogue and collaboration among the stakeholders. Dialogue among multiple stakeholders' dialogue, and securing the understanding of countries' or stakeholders' specific drivers and challenges are essential facets of an effort to advance and enact the change. Such dialogue on the topic of ATT deletion can serve as low-hanging fruit and an excellent case study on harmonization of regulatory requirements, but should take into consideration realities where quality systems, GMP, pharmacovigilance or a fully developed regulatory systems are not fully implemented.

Dr. Carmen Jungbäck from IABS contributed on the importance of data access to facilitate decision making, as it was the case for India. While full results of batch release testing cannot be published, it is still possible to summarize and make available the number of tests and vaccines tested. Other data, but with no reference to sensitive data like trade names would clearly show that hundreds of thousands of batches have been tested but zero deviations were identified. As reported in the earlier workshop's discussion, sharing the work done by industry colleagues, who worked with the regulatory authorities to build concrete cases, including documentation and data, to justify removal of ATT, could be of additional help in providing arguments to stakeholders.

Dr. Goel shared again the Indian experience, as it could work as a case study for many countries. In 2014 and 2015 manufacturers took action to foster the deletion of ATT and organized workshops with the participation from all the key stakeholders – manufacturers, IPC, NCL, RA. To reach their objectives, Dr. Goel considered a mix of factors was needed: 1) significant data compiled by all manufacturers showing zero ATT failures; 2) the NCL-compiles data from their own data with similar conclusions; 3) an open environment in India, allowing the various stakeholders to interact; 4) manufacturers feeling empowered by speaking together; 5) support from NGOs, like People for Ethical Treatment of Animals (PETA) and HSI, which backed the manufacturers; and 6) collection of documents, like the changes to Ph. Eur. Of course, different manufacturers have different level of implementation of GMPs, but regulatory audits ensured all of them were compliant. All these activities resulted in the RA changing its stance, first allowing a waiver to ATT, and then, in 2020, full deletion of the test was achieved for the human vaccines.

Concluding the session, Ms. Viviani highlighted another issue emerged during more than 10 years of discussion and activity on the topic: the inertia to change not caused by technical considerations but instead originating instead from low prioritization of ATT deletion by local stakeholders, which is something industry stakeholders are experiencing in some countries and that needs to be addressed through specific approaches.

Closing remarks: Importance of regulatory alignment

The workshop ended with the summary remarks from Mr. Rajinder Suri, CEO of DCVMN and Dr. Gilbert from the Bill & Melinda Gates Foundation. They commented and commended on the clarity emerged in the agreement on ATT as a nonspecific, not reproducible, obsolete test lacking relevance, and on the urgent need to maximize efforts to ensure its global deletion.

To achieve this goal, they remarked on the importance that production consistency be demonstrated, and the manufacturing processes is validated and is able to ensure no compromise exists on the quality and safety of the product. But these are achievable goals, as it has clearly been shown that there is no product requiring ATT, even for COVID-19 vaccines, because the test is of no consequence in determining quality or safety issues.

As to the 4th R mentioned during the event – whether it be intended as Rely, or as Remove – it certainly deserves the highest attention, because of the impact it would carry on millions of animals not used in an obsolete test, and on the reduced time to market and on the faster availability of the products. The deletion of ATT would also save millions of dollars for the manufacturers, which ultimately can be translated into price affordability in vaccines for billions of people. And, as vaccine equity and access, especially in Low- and Middle-Income Countries, has an immense global health impact, no effort should be spared for the deletion of a test like ATT, for the broader standardization of tests removal, for the implementation of optimized, state of the art standardized and harmonized testing requirements, and for the increase of dialogue and collaboration that can significantly help achieve these objectives. On the theme of dialogue, and collaboration, attention was called on yet another 4th R: Reaching out, to highlight the paramount role of networking.

In closing, a series of identified key actions were summarized:

Engage ICMRA and ICDRA and, continue to promote multi-stakeholders dialogue in collaboration and supported by WHO.

Rationalize the effort through DCVMN and other industry associations like EFPIA and IFPMA, facilitated by organizations like HSI, AFSA, IABS to build up new dialogue opportunities via workshops and conferences.

In conclusion of the workshop, HSI, EFPIA, IABS and all the participating organizations committed themselves to collaborate and endeavor to enact the agreed action points to further the deletion of ATT at the global level, by fostering policy and public health dialogue at the local and global level, stressing the scientific rationale for ATT elimination, and leveraging the proposed 4th Rs – Reliance, Removal, and Reaching out.

Disclaimer

This manuscript and the views expressed herein are those of the authors and do not necessarily reflect the views or policies of the various regulatory authorities, international organizations, and manufacturers or their associations.

Author contributions

LV wrote the manuscript. All the other authors contributed equally to the review of the manuscript. No author received funding for their involvement.

Declaration of competing interest

Humane Society International receives funds from the .