New RSV Vaccine Shows Strong Protection for Newborns, UK Study Finds

A new vaccine introduced in the United Kingdom in 2024 is proving highly effective at protecting newborns from Respiratory Syncytial Virus (RSV). The vaccine is administered to pregnant women, with the goal of transferring immunity to their babies.

A study followed approximately 300,000 babies born in England between September 2024 and March 2025. The research focused on the real-world effectiveness of the maternal RSV vaccination program.

The study found the vaccine's protection for newborns is nearly 85% when administered at least four weeks before birth.

The findings also indicate that some protection is still possible with vaccination later in pregnancy, including when given with a two-week gap before birth. This is an important point for expectant mothers who may receive the vaccine later in their term.

Study Outcomes and Expert Guidance

During the study period, more than 4,500 babies were admitted to hospital with RSV. The majority of these hospital admissions were infants whose mothers had not received the RSV vaccine.

Commenting on the results, Dr. Watson explained the mechanism behind the timing of the vaccine's effectiveness: "If you've got a longer interval between when the vaccine gets given and when baby is born, then you get even better protection."

He also offered clear advice for pregnant women: "Get it on time. But if you can't, do get vaccinated all the way through the third trimester." This underscores that vaccination remains beneficial even later in pregnancy.

Vaccine Development

The vaccine was developed after clinical trials indicated it could sufficiently enhance a pregnant woman's immune system to transfer protective antibodies to the baby via the placenta. This method of protecting infants in their first vulnerable months is known as passive immunity.