RSV vaccine showed strong protection against infections and hospital stays
☕ Includes a question for the family ↓
Infections and vaccines after 50Part of a story we are following · 7 articles · See every update
If you or your parents are 50 or older, here is good news for this winter. In a large study of US veterans, an mRNA RSV vaccine called mRNA-1345 gave strong protection against RSV infections, and the biggest payoff was staying out of the hospital.
One shot lowered the risk of an RSV hospital stay by 81.8% over a single season. That is the kind of result that makes a vaccine worth a conversation at your next pharmacy visit.
What is RSV, and why does it matter at 50 and up?
RSV is short for respiratory syncytial virus. Many people think of it as a children’s illness. It also sends a lot of older adults to the hospital each winter. The vaccine in this study, mRNA-1345, uses the same mRNA technology as some COVID vaccines.
How the study worked
Researchers used health records from the Veterans Health Administration. They looked at tens of thousands of veterans 50 and older who got a single dose of the vaccine between October 1, 2025, and January 31, 2026. Each one was matched with similar veterans who did not get an RSV shot, and everyone was followed for about 160 days, up to 24 weeks. The typical age was 73, and most participants were men. It was an observational study of one season, published Oct. 1, 2026, in JAMA Network Open.
What they found
The vaccine worked best where it counts most. Protection against an RSV hospital stay was 81.8%. Protection against any documented RSV infection was 60.3%, about 60%. Protection against an emergency room or urgent care visit for RSV was 60.2%, also about 60%.
| Any documented infection | 60.3% |
|---|---|
| Emergency or urgent care | 60.2% |
| Hospitalization | 81.8% |
| 50 to 59 | 82.9% |
|---|---|
| 80 or older (uncertain) | 28.6% |
Age made a difference. In veterans aged 50 to 59, protection against infection was 82.9%. In veterans 80 and older it was 28.6%, about 29%, and that number came with a wide range of uncertainty. So the shot clearly helped younger people in this group, and the picture for the oldest adults needs more study.
The researchers also ran a second check. They compared veterans who got the RSV shot and a flu shot on the same day with veterans who got only a flu shot. People who get shots can differ from people who don’t, so this was a fairer comparison. The protection looked even stronger: 86.9% against RSV hospital stays.
The takeaway is simple. A single RSV shot was linked to far fewer RSV infections, far fewer urgent visits and far fewer hospital stays during the season.
What you can do today
If you are 50 or older, or you help care for someone who is, ask your pharmacist whether an RSV vaccine is right for you this season. If you are already getting a flu shot, ask about getting both at the same visit.
Talk about it at home
RSV is a virus that gives people a bad cough and trouble breathing. Some older adults get sick enough to need the hospital. Scientists found that people who got a special shot were much less likely to end up there.
Question for the table
Here is a question to think about like a scientist: people who choose to get a shot might also be more careful in other ways. How could you test whether it was really the shot that helped?
Keep exploring
Copies this article and its questions so you can paste them into ChatGPT, Claude, Gemini or the AI you use, and keep the conversation going.
Questions and answers
- What is mRNA-1345?
- It is an mRNA vaccine against RSV, or respiratory syncytial virus, for adults.
- How well did it protect against hospital stays?
- Estimated protection against RSV hospital stays was 81.8% over one season.
- Does it work for people in their 80s?
- Protection against infection was lower at 80 or older (28.6%), and that estimate was uncertain. Ask your doctor or pharmacist what is best for you.
- Can I get it with my flu shot?
- The study included veterans who got both on the same day, and their protection looked as strong or stronger. Ask your pharmacist about timing.
