Low Dose Mpox Vaccination Found Effective

Research findings presented at the European Society of Clinical Microbiology and Infectious Diseases Global Congress show that a lower dose of the JYNNEOS® (MVA-BN) mpox vaccine is safe and generates a six-week antibody response equivalent to the standard regimen.

The results announced by the U.S. NIH on April 27, 2024, suggest that antibody responses contributed to the effectiveness of dose-sparing mpox vaccine regimens used during the 2022 U.S. outbreak.

The authors noted that because no defined correlates of protection against mpox—immune processes confirmed to prevent disease—these findings cannot predict the efficacy of dose-sparing regimens with certainty.

Real-world data from the U.S. Centers for Disease Control and Prevention and others have shown similar vaccine effectiveness for the dose-sparing regimen given intradermally and the standard regimen given subcutaneously.

According to the NIH, a study of the standard JYNNEOS regimen in adolescents is ongoing and will report findings later this year.

An earlier press release stated that the antibodies produced by JYNNEOS against mpox wane significantly within a year of receiving the vaccination. In contrast, among individuals who had received childhood smallpox vaccination, most had detectable VACV IgG one year after vaccinations.

In April 20224, JYNNEOS became commercially available in the U.S. by establishing additional pathways for vaccine procurement, distribution, and reimbursement by public and private payers, including community pharmacies.

Mpox vaccinations are essential since the number of mpox cases in the U.S. has more than doubled compared to Week #15 in 2023. As of April 13, 2024, 750 mpox cases had been reported, compared to 336 cases at the same time last year.