Prioritising immunisation across the life course - Authors' reply.

Anja Saso and colleagues rightly emphasise the importance of quantifying pandemic-related effects on maternal immunisation, with the IMmunising PRegnant women and INfants neTwork highlighting the multifaceted disruptions in 2020 and incomplete recovery to date among 18 countries. Our study, which modelled the effects of COVID-19 on routine childhood immunisation in 2020, focused on one part of the life course where vaccination can improve health and wellbeing. But the ambition of the Immunization Agenda 2030 is broader: a world where everyone benefits from vaccines at every age.

Immunisation during pregnancy protects both women and newborn babies against several infectious diseases, including tetanus, pertussis, and influenza. Robust maternal immunisation programmes also serve as key platforms for introducing new and future vaccines (eg, COVID-19, respiratory syncytial virus, and group B Streptococcus). Yet differences in access to and inequities in these programmes long predate the COVID-19 pandemic. Formal maternal immunisation policies and guidelines, which “underpin the quality and scope of health services”, have been fairly limited among lower income countries for some vaccines (eg, pertussis and influenza), and there are serious data challenges for comprehensively monitoring vaccination across the life course. Aside from maternal tetanus immunisation, multi-country health surveys rarely collect information on the vaccines received beyond childhood, and global syntheses of reported administrative data often do not have detailed coverage estimates for older age groups. As underscored by Saso and colleagues, the absence of timely, granular data poses large obstacles to understanding acute and long-term gaps in immunisation services beyond childhood vaccination.

Improving vaccination across the life course, from infancy to old age, is a strategic priority of the Immunization Agenda 2030. Increasing the reach of maternal immunisation services contributes to these aims, and formally including more vaccines—namely, pertussis, influenza, and now COVID-19, among others—through such programmes will benefit many. However, fully implementing a life course approach will require expanding vaccine policy and administration in most countries. For instance, universal influenza and diptheria, tetanus, and pertussis booster vaccinations could additionally protect individuals not reached through maternal immunisation or routine childhood programmes (eg, men and older adults). In parallel, data systems that effectively track vaccination status and needs over the lifespan are necessary for monitoring progress and promoting equitable access.

The COVID-19 pandemic has substantially affected immunisation services for all populations. The global roll-out of COVID-19 vaccines, which includes age groups often missed by traditional immunisation platforms, offers an opportunity to rethink how, and to whom, vaccines are delivered. Leveraging the lessons learned and successful strategies used during the pandemic could not only augment child and maternal immunisation services but also pave the way for a future in which “everyone, everywhere, at every age fully benefits from vaccines for good health and well-being”.

All authors receive funding from the Bill & Melinda Gates Foundation. NF receives funding from Gates Ventures. We declare no other competing interests.