The companies, which developed one of the two COVID-19 vaccines to be authorized in the U.S. so far, are conducting a global Phase 2/3 study to evaluate the safety, tolerability and immunogenicity of the vaccine in preventing COVID-19 in healthy pregnant women 18 years of age and older, according to a news release.
Pfizer and BioNTech’s Phase 2/3 trial is a randomized, placebo-controlled, observer-blind study in approximately 4,000 healthy pregnant women vaccinated during 24 to 34 weeks of gestation. The study will evaluate the safety, tolerability and immunogenicity of two doses administered 21 days apart.
Each participant will be involved in the study for approximately seven to 10 months, depending on whether she was randomized to receive the vaccine or a placebo. The study will also assess the safety in infants of vaccinated pregnant women and the transfer of potentially protective antibodies to the infants, who will be monitored through approximately six months of age.
“We are proud to start this study in pregnant women and continue to gather the evidence on safety and efficacy to potentially support the use of the vaccine by important subpopulations,” Pfizer senior VP of vaccine clinical R&D Dr. William Gruber said in the release. “Pregnant women have an increased risk of complications and developing severe COVID-19, which is why it is critical that we develop a vaccine that is safe and effective for this population. We are deeply thankful to the volunteers who are enrolling in the trial, and site investigators who are leading this work.”
The companies also expect to begin additional studies in children between five and 11 years old over the next couple of months, as well as in children younger than five later this year. Currently, the safety and efficacy of the vaccine is being evaluated in subjects between 12 and 15 in a global Phase 3 study, with results expected in the second quarter of 2021. Pfizer and BioNTech also plan to evaluate the vaccine in those with compromised immune systems.
“Enabling broad access to our highly effective COVID-19 vaccine is an important goal for us. Now that we are seeing successful initial implementation of vaccine campaigns with BNT162b2 across the globe, it is time to take the next step and extend our clinical program to other vulnerable populations, such as pregnant women, to potentially protect both them and future generations,” BioNTech chief medical officer Dr. Özlem Türeci said.