Two Vaccine Targets on Virus May Be Better Than One

By Reuters Staff

March 14, 2022

(Reuters)- An experimental vaccine developed by GeoVax Labs Inc succeeded in promoting development of antibodies that target two different sites on the virus in a small pilot study and has been advanced to mid-stage clinical trials, researchers reported.

Like currently available COVID-19 vaccines, GeoVax's GEO-CM04S1 induces immune responses that target the spike protein on the surface of the virus. But it also targets the "nucleocapsid," or shell, of the virus. In the study reported in The Lancet Microbe, 56 volunteers received the vaccine, which uses a modified vaccinia ankara vector to deliver genetic instructions for making antigen proteins. Overall, 94% developed antibodies against the spike and the nucleocapsid protein, according to the research team from City of Hope National Medical Center in Duarte, California. Other components of the immune system also responded well, including T cells, which help to protect against severe infection.

Two mid-stage trials of the vaccine are now underway. One is testing its safety and effectiveness in immunosuppressed patients with blood cancer. The other is testing it as a booster in healthy adults who previously received vaccines from Moderna, Pfizer/BioNTech or Johnson & Johnson. The studies will look at the level of antibodies that can neutralize the Omicron variant, the researchers said.

In separate experiments, Chinese researchers tested an inhalable antibody drug that also targets two sites on the virus. In mice infected with the coronavirus, the treatment appeared very effective, they reported in the journal Cell.

SOURCES: https://bit.ly/3Cyzgyq The Lancet Microbe and https://bit.ly/36cZhqR Cell, both online March 9, 2022.

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