Reduced Odds of Mpox-Associated Hospitalization Among Persons Who Received JYNNEOS Vaccine — California, May 2022–May 2023
Samuel Schildhauer, Kayla Saadeh, J. C. Vance, Joshua Quint, Tarek Salih, Timothy Lo, Awa Keinde, Edwin Chojolan, Esther Gotlieb, Marisa Ramos, Eric Chapman, Philip J. Peters, Jessica Watson, Kelly A. Johnson, Eric C. Tang, Kathleen Jacobson, Robert E. Snyder
Abstract
The effectiveness of 1 dose of JYNNEOS vaccine (modified vaccinia Ankara vaccine, Bavarian Nordic) against hospitalization for mpox (caused by Monkeypox virus), has been demonstrated; however, the impact of 2 doses on hospitalization risk, especially among persons infected with HIV, who are at higher risk for severe disease, is an important factor in evaluating vaccine effectiveness against mpox disease severity and Monkeypox virus infection.Surveillance data collected by the California Department of Public Health were used to evaluate whether receipt of 2 doses of JYNNEOS vaccine reduced the odds of hospitalization among persons with mpox.The odds of hospitalization among persons with mpox who had received 1 or 2 JYNNEOS doses were 0.27 (95% CI = 0.08-0.65)and 0.20 (95% CI = 0.01-0.90),respectively, compared with unvaccinated mpox patients.In mpox patients with HIV infection, the odds of hospitalization among those who had received 1 JYNNEOS vaccine dose was 0.28 (95% CI = 0.05-0.91)times that of those who were unvaccinated.No mpox-associated hospitalizations were identified among persons infected with HIV who had received 2 JYNNEOS vaccine doses.To optimize durable immunity, all eligible persons at risk for mpox, especially those infected with HIV, should complete the 2-dose JYNNEOS series.** Certain California residents received JYNNEOS vaccine before this date.May 26, 2022, was used for this analysis because this was the date that the California Department of Public Health had doses recorded among lots received by the Administration for Strategic Preparedness and Response for use as part of the state's ongoing response to mpox. Defined as the population recommended to receive the vaccine, which was estimated by CDC using 2021 data for men who have sex with men (MSM) with HIV preexposure prophylaxis indications and 2020 data for HIV prevalence among MSM from CDC AtlasPlus.