JYNNEOS Vaccine: Effective at Preventing Mpox-Associated Hospitalization

People at risk for mpox are advised to receive two doses of JYNNEOS vaccine (originally designed for smallpox prevention but also approved for mpox prevention in adults); however, data on the effectiveness of JYNNEOS — especially in persons with HIV — remain sparse. Investigators in California interviewed persons with confirmed mpox to ascertain whether they had been hospitalized. Vaccination was defined as receipt of at least one dose, at least 14 days prior to initial symptoms of mpox. Receipt of vaccine <14 days prior to symptoms was defined as postexposure prophylaxis (PEP).

Of 4611 persons (94% men) with mpox, 230 received one dose of vaccine, 79 received two doses, and 457 received PEP; in all, 250 were hospitalized. The odds of hospit…