Authors' response.

We acknowledge pertinent comments from Alavian on our article1. There is no doubt that transfusion-transmitted infectious diseases (TTID) are severe side-effects of blood transfusions. There are several options that can be tried to make blood transfusion safer. First of all, transfusions must be given to patients on strict indications and there is room for improvement on evidence-based use of blood and blood components. Second, blood products from non-remunerated voluntary repeat donors (NRVRD) are safer than from family and replacement donors and in almost all countries there are efforts made to increase the number of NRVRD23. There are however, both cultural and political obstacles that need to be overcome to have 100 per cent NRVRD in all countries. Also, donor selection may be a challenge in areas endemic for hepatitis, malaria and dengue fever. What is considered proper donor selection in most countries, may lead to deferral of too many donors and lack of sufficient blood supply in other countries. Lastly, testing may give results that are far beyond the quality claimed by the manufacturer due to testing in a not ideal laboratory environment4. False negative test results are the main reason for hepatitis B virus (HBV) TTID in Vietnam (unpublished observations).

We agree with Alavian that HBV nucleic-acid testing (NAT) may not be feasible in Vietnam today. More sensitive ELISA test may be implemented. HBV vaccination will give a safer donor population in the future and efforts made to include 100 per cent NRVRD is a goal which always must be kept in mind by politicians and health care workers. HBV vaccination was introduced in Vietnam National Universal Immunization Programme of infants in 20035 and after 2021 blood donors from the vaccinated population can be a source of HBV ‘safe’ blood for transfusion. Safe and sufficient blood supply and transfusions given on correct indications will reduce TTID.