How Well Does the RSV Vaccine Actually Protect You? What New Research Shows

What is RSV, and who should get vaccinated against it?

RSV, or respiratory syncytial virus, is a common virus that can cause a serious lung infection. For most healthy people, it feels like a cold. But for certain groups, it can lead to a hospital stay or worse. Health experts recommend a one-time RSV vaccine for everyone age 75 and older, and for adults 50 to 74 who are at higher risk of severe illness — for example, people with heart disease, lung disease like COPD, chronic kidney disease, or a weakened immune system. Pregnant people are advised to get an RSV vaccine between 32 and 36 weeks of pregnancy if that window falls during RSV season, roughly fall through winter, so the protection passes to their newborn. Babies younger than 8 months are protected with a preventive antibody shot, not a vaccine, during their first RSV season. Some babies and toddlers 8 to 19 months old who are at higher risk get the same kind of shot heading into their second season.

Could this new research apply to you?

A team of researchers reviewed 75 studies published through mid-2026 on how well RSV vaccines and antibody shots work, and how safe they are, ahead of the 2026-2027 respiratory season. If you’re 75 or older, you’re 50 to 74 with one of the health conditions above, you’re pregnant during RSV season, or you’re a parent of a baby under 8 months, this research is about your specific situation — not just a general population number.

How well did the vaccine protect older adults?

Among adults 60 and older, RSV vaccination was linked to about an 83% lower chance of being hospitalized for RSV (the number could reasonably be as low as 43% or as high as 97%, based on the range researchers calculated). That’s a strong result, and it held up across several studies looking at hospital stays, ER visits, and lab-confirmed RSV illness.

Does the protection wear off over time?

Some evidence suggests it might. In one large study of military veterans, protection against hospitalization was 81% in the first six months after vaccination but dropped to about 49% by 12 to 18 months later. A different study, though, found effectiveness after two RSV seasons wasn’t meaningfully different from after just one season. Researchers say this is still an open question — there isn’t yet enough evidence to know exactly how long one dose keeps working, which is part of why more follow-up research is planned.

What if you have a weakened immune system?

The vaccine still helped, but not by quite as much. Among older adults who were immunocompromised — for example, due to cancer treatment, an organ transplant, or a condition like HIV — protection against RSV hospitalization ranged from about 30% to 73%, depending on the study. That’s lower than the roughly 83% seen in the broader group of older adults, so it’s worth knowing if this describes you or someone you care for.

What did the research find for pregnant people and infants?

For people vaccinated between 32 and 36 weeks of pregnancy, their newborns had somewhere between 51% and 70% lower risk of being hospitalized for RSV in their first four months of life, depending on the study. For babies who received the preventive antibody shot instead, protection against RSV hospitalization ranged from about 64% to 93%, with the strongest protection seen in babies who got the shot right around birth. None of the studies that compared vaccinated and unvaccinated pregnant people found a higher rate of preterm birth or other pregnancy complications linked to the vaccine.

Is the RSV vaccine safe?

So far, the safety picture is largely reassuring, with one signal researchers are still watching. Across three large clinical trials involving more than 130,000 people, no cases of Guillain-Barré syndrome (GBS, a rare condition that causes temporary nerve damage and muscle weakness) were reported. However, one smaller study of older adults in Scotland found a possible increase in GBS cases in the six weeks after vaccination. Because of findings like this, RSV vaccine safety labels now include a warning about GBS. The FDA has said there isn’t enough evidence to prove the vaccine causes GBS, and that the benefits of vaccination still outweigh this rare, unconfirmed risk.

What should you do next?

If you fall into one of the groups above — 75 or older, 50 to 74 with a chronic health condition, pregnant during RSV season, or caring for a young infant — this research suggests the RSV vaccine or antibody shot is worth asking about. It won’t guarantee you avoid RSV entirely, but the studies reviewed here consistently found fewer hospital stays among people who were vaccinated compared with those who weren’t.

Source: Senerth E, Sheikholeslamian SM, Babatunde I, et al. “RSV Immunization Effectiveness and Safety for the 2026-2027 Respiratory Season.” JAMA, published online September 2, 2026. https://doi.org/10.1001/jama.2026.17871