New COVID-19 Vaccine Defends Monkeys Against Infection

Researchers from Beijing-based Sinovac Biotech have reported preliminary results of a study into the development of a vaccine against COVID-19. This is some of the first evidence of a vaccine showing efficacy in a primate experimental model (rhesus macaques) and provides hope for a global community anxiously awaiting countermeasures against the escalating pandemic.

Experts estimate that a clinically-available vaccine against SARS-CoV-2 could take 18 months or longer to develop, even at an accelerated pandemic pace. A new vaccine needs to be thoroughly tested for safety and efficacy in animals and humans prior to its commercialization. Before phase I testing, in which a small group of healthy volunteers receives the vaccine in development, vaccines are typically tested in non-human primates, which share physiological and disease process similarities with humans.

In Sinovac’s study, the vaccine testing protocol involved two doses of inactivated SARS-CoV-2, administered to a cohort of eight rhesus monkeys. The animals were allowed to develop a natural immune response to the inactivated virus over the course of three weeks. They were then exposed to live, unadulterated SARS-CoV-2 to test the protective capabilities of the vaccine treatment.