Does taking the flu shot with RSV vaccine work well for seniors?
For seniors, getting both the flu shot and the RSV vaccine at the same visit is convenient and generally effective. A large phase 3 study in adults 65 and older found that giving the high-dose flu vaccine (QIV-HD) together with the RSV mRNA vaccine (mRNA-1345) produced a strong immune response against influenza, meeting the standard for noninferiority compared to giving them separately. However, the RSV antibody response was slightly lower with coadministration, though still within an acceptable range. No safety concerns were raised.
What the research says
A randomized, observer-blind phase 3 study involving 1,900 adults aged 65 and older compared coadministration of the RSV mRNA vaccine (mRNA-1345) with a high-dose quadrivalent influenza vaccine (QIV-HD) versus giving the vaccines 21 days apart 1. For influenza, the immune responses against all four strains (H1N1, H3N2, and two B strains) were noninferior when given together, meaning the flu shot worked just as well 1. For RSV, the immune response was slightly lower with coadministration, but the geometric mean ratio (0.868-0.948) still fell within the accepted noninferiority margin 1. Reactogenicity was mild to moderate, and there were no related serious adverse events or deaths 1. These results suggest that getting both vaccines at once is a safe and practical option for seniors, though the RSV protection might be marginally reduced. Other research confirms the importance of both vaccines: the 2024-2025 flu vaccine reduced hospitalization by 40% in adults 8, and RSV causes significant disease in older adults, with mortality rates similar to influenza 11.
What to ask your doctor
- Given my age and health, is it recommended that I get both the flu shot and RSV vaccine this season?
- If I get both vaccines at the same visit, should I expect any difference in how well the RSV vaccine works?
- Are there any specific side effects I should watch for when receiving both vaccines together?
- Would you recommend the high-dose flu vaccine for me, and does it pair well with the RSV vaccine?
- How do the benefits of coadministration compare to the convenience of getting them separately?
This question is drawn from common patient questions about Geriatrics & Aging and answered using cited medical research. We do not provide individualized advice.