Vaccine Pregnancy Trials Begin in Bid to Fill Data Void (1)

Covid vaccine developers are beginning trials in pregnant women, looking to provide reassurance that the shots are safe for expectant mothers.

Pfizer Inc. and German partner BioNTech SE dosed the first patients in a trial of their messenger RNA vaccine in 4,000 women in the latter stages of pregnancy, the companies said on Thursday. The partners will run a mid-stage study for 350 volunteers between 27 and 34 weeks gestation to confirm safety, before moving into advanced trials for women between 24 and 34 weeks pregnant.

AstraZeneca Plc. and Johnson & Johnson are planning to run trials in coming months....