The FDA recently approved Pfizer's RSV vaccine (ABRYSVO) for pregnant women at 32-36 weeks gestation, despite safety concerns. The vaccine appears to increase the risk of preterm birth, and trials for a competitor's nearly identical vaccine were halted due to a number of neonatal deaths (in addition to preterm births).
The vaccine is expected to become widely available in October. I'm a new mom myself and I'm floored. Pregnant women are going to be under a lot of pressure to receive this vaccine.
The vaccine is expected to become widely available in October. I'm a new mom myself and I'm floored. Pregnant women are going to be under a lot of pressure to receive this vaccine.
While all members of the Vaccines and Related Biological Products Advisory Committee (VRBPAC) voted positively on efficacy, four out of 14 voted that the data were not adequate to support safety.
As The BMJ revealed earlier this month, Pfizer’s clinical trials showed increased levels of preterm births among vaccinated women, and GSK, which was working on a similar vaccine, halted vaccination in its phase 3 trials after observing an increase in neonatal deaths and preterm births.
On investor calls in October 2022 and March 2023 Steve Scala, a pharmaceutical industry research analyst and former pharmacist, described Pfizer’s and GSK’s vaccines as “Coke and Pepsi” and said he was “wondering why Pfizer can continue and feel comfortable” given that there didn’t seem to be a reason for a different incidence of preterm births in the two studies. On both occasions, Pfizer representatives did not give reasons why their vaccine would perform differently to GSK’s.
Overall, there was unease regarding safety, with demands for more complete data and an FDA enforced post-marketing requirement to conduct “aggressive” surveillance following approval.
“We should be raising the bar higher,” said Amanda Cohn, director of the Division of Birth Defects and Infant Disorders at the Centers for Disease Control and Prevention, who voted “yes” on safety. She noted that much larger vaccine studies had been conducted to root out safety problems and these should have been done for a vaccine involving pregnant women to provide them with the information they need to decide on vaccination.
Maternal RSV vaccine: Further analysis is urged on preterm births
A “safety signal” in a similar respiratory syncytial virus (RSV) vaccine has led to trials being stopped and prompted calls for a cautious approach to using the vaccine in pregnant women, reports Hristio Boytchev Experts have called for further analysis of trial data and post-approval...
www.bmj.com
FDA advisers back Pfizer’s maternal RSV vaccine after voicing safety concerns
Whether Pfizer’s maternal respiratory syncytial virus (RSV) vaccine candidate increases the risk of preterm birth dominated discussions at a meeting last week of the committee advising the US Food and Drug Administration (FDA).1 While all members of the Vaccines and Related Biological Products...
www.bmj.com