FDA Approves First Live, Nonreplicating Vaccine for Smallpox, Monkeypox

The FDA has approved the first smallpox and monkeypox vaccine, live, nonreplicating (Jynneos, Bavarian Nordic) for the prevention of the 2 viruses.

While naturally occurring smallpox was eradicated in 1980 following the global Smallpox Eradication Program, monkeypox is still rarely found outside of the United States. While typically milder than smallpox, the illness can still be fatal. The United States most recently experienced an outbreak of monkeypox in 2003, the first time that human monkeypox was reported outside of Africa.

Bavarian Nordic's vaccine is made from the Modified Vaccinia Ankara (MVA) virus, which is closely related to, but less harmful than, the variola or monkeypox viruses. MVA does not cause disease in humans and is nonreplicating, meaning it cannot reproduce in human cells.

The effectiveness of the vaccine was determined in a clinical study comparing it with ACAM2000, an FDA-approved vaccine for smallpox. The study included approximately 400 healthy adults, half of whom received 2 doses of the vaccine 28 days apart while the other half received 1 dose of ACAM2000.

The effectiveness of the smallpox and monkeypox vaccine, live, nonreplicating vaccine was inferred from the antibody responses in the smallpox clinical study of participants, and from studies in nonhuman primates.

The most commonly reported adverse effects included pain, redness, swelling, itching, firmness at the injection site, muscle pain, headache, and fatigue.

The vaccine will be available for patients determined to be at a high risk of smallpox or monkeypox infection, and is part of the Strategic National Stockpile for use in a public health emergency that is severe enough to deplete local supplies.

REFERENCE

Commissioner Of the FDA. FDA approves first live, non-replicating vaccine to prevent smallpox and monkeypox. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements/fda-approves-first-live-non-replicating-vaccine-prevent-smallpox-and-monkeypox. Published September 24, 2019. Accessed September 24, 2019.