Research on vaccines for pregnant and lactating women raises ethical issues that differ from those in therapeutic research. Vaccines are given to healthy individuals to prevent disease, therefore the acceptable level of risk is generally lower and requires careful assessment of potential benefits and harms. In early trials, women may not gain direct benefit themselves, making it essential to carefully weigh risks and benefits during pregnancy, when both mother and fetus are particularly vulnerable (see Figure 1).

Figure 1 – Practical application of ethical dimensions in vaccine trials  

Risk benefit assessment framework for use of vaccines in pregnancy

Decisions about vaccine use in pregnancy often need to be made with limited data on safety or immune response in this group. These evidence gaps make it harder for regulators, policy-makers, and health workers to give clear guidance, and they complicate informed consent. Where sufficient non-clinical and human safety data exist, inclusion of pregnant women should be considered earlier in product development rather than deferred until post-licensure.

A structured risk–benefit framework (Table 1) may help guide these decisions by:

• considering timing of vaccination, distribution of benefits, and potential public health impact; 
• ensuring pregnant and lactating women, as well as women’s advocacy groups, are involved in its design so that it reflects their needs and concerns; 
• emphasizing equity, transparency, and local context to build trust and support uptake.