A vaccine developed by the Danish company Bavarian Nordic has received FDA approval to prevent infections by monkeypox, as well as protect against the threat of a smallpox bioterror attack.
This approval makes Bavarian Nordic’s vaccine the only approved vaccine in the world for preventing monkeypox, a rare viral infection that is similar to smallpox but less severe. In addition, the vaccine will be stockpiled by the US as a precaution against the return of smallpox.
Since smallpox was eradicated in the wild in the 1970s, populations have stopped receiving vaccinations against the disease. However, samples of the smallpox virus remain contained in secure research labs, and the disease has even been weaponized in the past. This means that smallpox could be released in an act of bioterrorism if it falls into the wrong hands.
“Although naturally occurring smallpox disease is no longer a global threat, the intentional release of this highly contagious virus could have a devastating effect,” stated Peter Marks, Director of the FDA’s Center for Biologics Evaluation and Research.
Many countries already have stockpiles of smallpox vaccines in case the disease is released again. However, the traditional smallpox vaccine uses viral vectors that can replicate in the body. This risks adverse events such as necrosis and infection, especially in people with weakened immune systems. In contrast, Bavarian Nordic’s vaccine uses a viral vector that cannot replicate itself. This vaccine showed no serious adverse events in a phase III trial, making it more suitable for immunocompromised people than the standard vaccine.
The vaccine is also able to protect against monkeypox. The monkeypox virus is from the same genus as the smallpox virus, but is milder and less easily transmitted between humans. The disease has mainly been limited to regions of Africa including Nigeria, but was recorded in Europe for the first time last year. Bavaria Nordic believes that the vaccine will be in demand for travelers to affected areas.
Smallpox isn’t the only disease that could be used in bioterrorism. Anthrax was sent in letters to victims in the US in 2001, causing five deaths. The plague is a different threat that could be weaponized as an aerosol. The UK biotech Enesi Pharma is working to improve vaccine options for the plague, with a needle-free vaccine in development with the University of Oxford.
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