Experts have called for further analysis of trial data and post-approval monitoring of Pfizer’s maternal RSV vaccine candidate after GSK’s trials of a similar product were halted over a rise in preterm births and neonatal deaths.
An advisory committee from the US Food and Drug Administration (FDA) is set to discuss the vaccine on 18 May1 as part of a fast tracked priority review, with a decision expected by August.
Pfizer published the results of an interim analysis of its phase 3 trial2 in April 2023, saying that the vaccine was effective against medically attended severe RSV in children and that no safety concerns were identified.
But the results have raised concerns34 about a possible increase in preterm births, and experts are calling for further analyses of the data and for post-approval monitoring of the vaccine, should the FDA approve it.
GSK halts its trials
In February 2022, GSK halted enrolment and vaccination across three phase 3 trials of its maternal RSV vaccine candidate, citing …