Despite being a high-risk population, pregnant women are often excluded from vaccine trials, from priority access to therapeutics, and experience delayed entry into public health vaccination programs.”

There are no specific vaccines for avian influenza in humans, though trial vaccines have been developed for pandemic preparedness in some countries. But these vaccines are not recommended for pregnant women because of a lack of safety data.

“That’s one of the challenges we often have with vaccines, as it is considered unsafe to test them in pregnant women,” Purcell said. “I think as we move forward, what we need to do is think about how we get data on pregnant women.

“If women are enrolled in vaccine safety studies, sometimes those women will inadvertently become pregnant, and there’s an opportunity to ethically study what happens to those women.”

This is the point of the study, the point of the article, the interest being advocated here by Dr Rachael Purcell. Conducting vaccine trials on pregnant women.

There are very good reasons why this is not done. Firstly, the fetus could be harmed or killed. Secondly, the data from pregnant women is useless for assessing safety and efficacy in anyone other than a pregnant woman. As the vast majority of the population are not pregnant women, it is unnecessarily hazardous and a waste of limited resources to test a vaccine on pregnant women first. That can come later, once you’ve developed a useful vaccine and deployed it widely, reducing the risk of infection of everyone in a society, including pregnant women.