Study shows complete protection against monkeypox

An article that describes complete protection of non-human primates against an extremely pathogenic monkeypox challenge after vaccination with Inovio Pharmaceuticals’ smallpox DNA vaccine has been published in The Journal of Infectious Diseases.

This research has been spurred on by the potential threat of a smallpox-based bioterrorist attack.

The DNA vaccine administered to the monkeys shows strong antibody-based immune responses that were similar to the current approved live viral vaccine, called Dryvax. The study is titled “Multivalent Smallpox DNA Vaccine Delivered by Intradermal Electroporation Drives Protective Immunity in Nonhuman Primates Against Lethal Monkeypox Challenge.”

The highly concentrated DNA vaccine generated a diverse, high titer antibody response against eight different DNA-encoded antigens that were delivered simultaneously as a single formulation.

The monkeys were given three immunizations at one month intervals and were then given a deadly dose of monkeypox virus one month later. All 10 animals that were vaccinated survived the challenge and had significantly lowered amounts of the virus circulating in the body. In addition, their disease-related sickness symptoms declined. Only one member of the control group that did not receive the vaccine survived.

“These results are remarkable in many ways,” Stanley A. Plotkin, a Wister Institute and University of Pennsylvania emeritus professor, said. “DNA for multiple smallpox genes that code for protective antigens was given transcutaneously by electroporation and the responses were protective against smallpox, but notable because prior DNA vaccines have had difficulty eliciting antibodies. Finally, this DNA vaccine is actually safer than the old smallpox vaccine and could be useful in the event of a bioterrorist attack necessitating rapid vaccination of people, some of whom might be immunosuppressed; and also if monkeypox is again introduced into the United States.”