Skip to main content

Immunity From Mpox Vaccine May Be Waning

By Lori Solomon HealthDay Reporter

Medically reviewed by Carmen Pope, BPharm. Last updated on Oct 6, 2024.

via HealthDay

FRIDAY, Oct. 4, 2024 -- Immunity against mpox may be waning for those vaccinated with the modified vaccinia Ankara-Bavarian Nordic (MVA-BN; Jynneos) vaccine, according to a research letter published online Oct. 3 in the Journal of the American Medical Association.

Ai-ris Y. Collier, M.D., from the Beth Israel Deaconess Medical Center in Boston, and colleagues assessed mpox-specific immune responses for 12 months after MVA-BN vaccination. The analysis included serum specimens from a convenience sample of adults who received the MVA-BN vaccine (26 with one dose and 22 with two doses) or who had a confirmed diagnosis of mpox infection (three individuals) during the 2022 outbreak.

The researchers found that in participants who received two doses of the vaccine, median binding antibody enzyme-linked immunosorbent assay (ELISA) titers to mpox M1R, B6R, A35R, A29L, and H3L antigens, respectively, were 28, 25, 25, 27, and 27 at baseline, peaked at 112, 384, 85, 29, and 76 at week 3 after vaccination, and then declined to 38, 82, 32, 25, and 31 at 12 months. With one vaccine dose, the median binding antibody ELISA titers to mpox M1R, B6R, A35R, A29L, and H3L antigens peaked at 45, 90, 32, 31, and 28, respectively, at week 3, but then declined to 33, 43, 30, 25, and 28, respectively, at 12 months. After either one or two doses, mpox serum neutralizing antibody titers were minimal at three months. However, after natural infection, high titers of mpox neutralizing antibodies were detected at three months and persisted nine months after infection.

"These data suggest that protective immunity may be waning in individuals who were vaccinated with MVA-BN in 2022 and that boosting may be required to maintain robust levels of protective immunity," the authors write.

One author disclosed ties to the pharmaceutical industry.

Abstract/Full Text

Disclaimer: Statistical data in medical articles provide general trends and do not pertain to individuals. Individual factors can vary greatly. Always seek personalized medical advice for individual healthcare decisions.

© 2025 HealthDay. All rights reserved.

Read this next

35 Percent of Eligible Children Receive RSV Prophylaxis With Nirsevimab

TUESDAY, July 22, 2025 -- Despite near universal availability of nirsevimab, only 35 percent of eligible children receive nirsevimab for respiratory syncytial virus (RSV)...

2020 to 2024 Saw Drop in Flu Vaccine Uptake Among U.S. Adults

FRIDAY, July 18, 2025 -- There was an overall decrease in influenza vaccine uptake among U.S. adults from 2020 to 2024, according to a study published online July 16 in PLOS...

No Risks Seen With Early Childhood Exposure to Aluminum-Adsorbed Vaccines

TUESDAY, July 15, 2025 -- Early childhood exposure to aluminum-adsorbed vaccines is not associated with an increased risk for autoimmune, atopic or allergic, or neurodevelopmental...

More news resources

Subscribe to our newsletter

Whatever your topic of interest, subscribe to our newsletters to get the best of Drugs.com in your inbox.