Pfizer Inc and BioNTech SE have started an international study with 4,000 volunteers to evaluate the safety and effectiveness of their Covid-19 vaccine in healthy pregnant women, the companies said on Thursday.
According to reports, pregnant women are at higher risk of developing severe Covid-19, and many public health officials have recommended some women in high-risk professions take coronavirus vaccines even without proof they are safe for them.
senior vice-president of vaccine clinical research and development for Pfizer, Dr William Gruber said in an interview the company could have results by the fourth quarter of 2021.
He said, data so far suggest that pregnant women with Covid-19 have higher rates of severe disease. They also have higher rates of pregnancy complications, such as premature birth, compared with pregnant women not infected by the coronavirus.
He stressed further that increased risk is why US regulators and public health advisers “are interested in doing this in the first place – so people can be fully informed about the safety profile,”.
The new study will test pregnant women aged 18 and older in the United States, Canada, Argentina, Brazil, Chile, Mozambique, South Africa, the UK and Spain.
Women will receive the vaccine during weeks 24-34 of gestation, getting two shots 21 days apart – the same regimen used in the larger clinical trial.
Shortly after giving birth, participants who got a placebo in the trial will be given an opportunity to get the actual vaccine, while remaining part of the study, the companies said.
The trial will also assess whether vaccinated pregnant women transfer protective antibodies to their babies.