The results of a study published in the New England Journal of Medicine revealed that Pfizer Incs experimental respiratory syncytial virus (RSV) vaccine was 82 % effective in preventing severe infections in children when given to pregnant mothers in the second half of their pregnancy.

Pfizer revealed preliminary trial data on the vaccine in November, which is presently being reviewed by health regulators in the United States and Europe. In the United States, the Food and Drug Administration is expected to make a decision on its use by August.

With FDA approval, Pfizer′s shot might become the first maternal immunization accessible to prevent the condition in newborns.

Sanofi and AstraZeneca are working on a single-dose antibody, nirsevimab, for RSV prevention in newborns, which the FDA is also reviewing.

RSVpreF, a vaccine developed by Pfizer, achieved one of the studys two primary objectives. It was about 82% efficient in preventing severe lower respiratory tract sickness in newborns in their first 90 days of life, such as very low oxygen levels or the requirement for ventilator assistance.

Pfizer said severe sickness occurred in six infants whose moms received the vaccination within three months, compared to 33 infants in the placebo group who contracted severe RSV infections. As part of the study, the company tested 3,570 newborns.

In the first 180 days, the injection was 69.4% effective in preventing severe infections. Serious illness occurred within six months in 19 of the vaccine groups infants, compared to 62 of the placebo groups newborns. The shot failed to achieve a second primary goal of lowering non-severe sickness in babies.

The government data showed that 58,000 to 80,000 children under five are hospitalized in the United States each year owing to RSV infection, with infants being among those at greatest risk for serious disease. 

(Source: https://www.reuters.com/business/healthcare-pharmaceuticals/pfizer-rsv-vaccine-82-effective-vs-severe-infection-infants-final-data-shows-2023-04-05/)