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Volume 32, Number 2—February 2026
Dispatch
Effectiveness of RSV Vaccines against RSV-Associated Thromboembolic Events
, Heng-Ming Sung, Yue Zhang, Andrea Chavez, Amber Kautz, Josephine Mak, Morgan Najdowski, Yangping Chen, Yenlin Lai, Yixin Jiao, Yoganand Chillarige, Ruth Link-Gelles, and Amanda B. Payne
Table
Adjusted VE of RSV vaccine against RSV-associated TEs among community-dwelling Medicare beneficiaries >65 years of age, United States, October 1, 2023–March 30, 2024*
| Stratification or vaccination status | No. beneficiaries | No. RSV-associated TEs | Total no. TEs per 10,000 person-years | Median follow-up days contributed to category | Outcome rates per 10,000 person-years | Adjusted VE, % (95% CI) |
|---|---|---|---|---|---|---|
| Overall | ||||||
| Unvaccinated | 12,353,511 | 2,405 | 627 | 181 | 3.84 | Referent |
| Vaccinated |
3,204,875 |
96 |
109 |
132 |
0.88 |
79 (74–83) |
| Immunocompromised | ||||||
| Unvaccinated | 1,587,615 | 523 | 81 | 181 | 6.46 | Referent |
| Vaccinated |
509,928 |
36 |
17 |
131 |
2.07 |
69 (56–78) |
| Immunocompetent | ||||||
| Unvaccinated | 10,765,895 | 1,882 | 546 | 181 | 3.45 | Referent |
| Vaccinated |
2,694,947 |
60 |
92 |
132 |
0.65 |
82 (77–86) |
| Age 65–74 y | ||||||
| Unvaccinated | 6,711,712 | 630 | 341 | 181 | 1.85 | Referent |
| Vaccinated |
1,605,200 |
27 |
55 |
132 |
0.49 |
75 (63–83) |
| Age ≥75 y | ||||||
| Unvaccinated | 5,641,799 | 1,775 | 286 | 181 | 6.20 | Referent |
| Vaccinated |
1,599,675 |
69 |
54 |
131 |
1.27 |
80 (74–84) |
| Time since vaccination, d | ||||||
| 14–59 | 208,379 | 33 | 38 | 46 | 0.87 | 80 (72–86) |
| 60–119 | 840,280 | 44 | 44 | 60 | 1.01 | 79 (72–84) |
| >120† |
2,156,216 |
19 |
28 |
46 |
0.68 |
75 (60–84) |
| Vaccine product | ||||||
| Arexvy‡ | 2,193,463 | 74 | 74 | 130 | 1.00 | 76 (70–81) |
| Abrysvo§ | 1,011,412 | 22 | 35 | 137 | 0.63 | 85 (77–90) |
*Adjusted VE estimates from multivariable Cox proportional hazards models after controlling for age group, sex, race/ethnicity, social vulnerability index deciles, rural or urban category (determined by location of a beneficiary’s facility in a US Census Core Based Statistical Area or not), a count of the number of underlying medical conditions, immunocompromise status, influenza vaccination in the previous season, and COVID-19 vaccination during the current season. VE calculated by using the formula VE = (1 – hazard ratio) × 100 (Appendix, https://wwwnc.cdc.gov/EID/article/32/2/25-1520-App1.pdf). RSV, respiratory syncytial virus; TEs, thromboembolic events; VE, vaccine effectiveness. †Maximum number of days a beneficiary in interim analysis is contributing is 127 days. ‡GlaxoSmithKline, https://www.gsk.com. §Pfizer, https://www.pfizer.com.