New Delhi, Sep 21
Amid the rising global outbreak of Mpox, two separate studies have shown that the efficacy of Bavarian Nordic’s vaccine against the deadly infectious disease wanes “to undetectable levels” in 6-12 months.
Modified Vaccinia Ankara-Bavarian Nordic or MVA-BN is indicated for active immunisation against smallpox, Mpox, and related orthopoxvirus infections and disease in all adults 18 years of age and older.
The vaccine, administered as a 2-dose injection given 4 weeks apart, is the first jab against Mpox to be prequalified by the World Health Organization (WHO).
The first study, published in the open-access medical journal Eurosurveillance, demonstrates that “orthopoxvirus-specific binding and MVA-neutralising antibodies waned to undetectable levels one-year post-vaccination in at-risk individuals who received two doses of MVA-BN”.
Led by researchers from the Erasmus University Medical Center, in the Netherlands, the study called for continuous surveillance to understand the impact of declining antibody levels.
The team investigated 99 high-risk active gay, bisexual, or other men who have sex with men (GBMSM) and 19 laboratory workers in the Netherlands in 2022 and 2023.
The participants included both those born before and after 1974 when smallpox vaccine ceased to be administered in the Netherlands.