Zika infection in pregnancy can have devastating effects on normal fetal development. But pregnant women are often automatically excluded from vaccine trials over safety concerns.
The guidelines argue that those most at risk from the virus – pregnant women and their babies – should be at the centre of Zika vaccine development.
The guidance, developed with Wellcome funding, sets out how the research community can ensure that any vaccines developed are made available to those most at risk.
It puts forward three principles, each with recommendations directed at policymakers, funders, researchers, oversight bodies, regulatory authorities and the global public health community.
Since 2016, thousands of children across South America have been born with microcephaly, which causes abnormally small heads, after their mothers were infected with Zika.
Zika vaccine development is proceeding rapidly, with a number of vaccine candidates already moving into Phase II clinical trials.
The researchers argue that unless these recommendations are acted on soon, pregnant women and their babies will be un fairly excluded from the benefits of whichever vaccines prove effective. And pregnant women and their clinicians will lack the evidence they need to make informed decisions about using these vaccines.
Doing research studies with pregnant women has been historically challenging and ethically complex. The vast majority of clinical trials for all biomedical interventions, including vaccines, have excluded pregnant women.
There are many reasons for this, including overly cautious interpretations of what is allowed under research regulations and concerns about legal liability.
As a consequence, many drugs and treatments enter the market with little or no data on safety and efficacy in pregnancy – and it can take decades to generate this evidence post-authorisation.