On Sept. 3, 2020, Oregon Health & Science University (OHSU) announced that for the first time, early research in hamsters demonstrated that an investigational coronavirus vaccine candidate may help protect against severe COVID-19 disease.

The study, led by Beth Israel Deaconess Medical Center in Boston with contributions from Oregon Health & Science University, was published Sept. 3 in the journal Nature Medicine. It examines the investigational vaccine being developed by Johnson & Johnson affiliate Janssen Pharmaceuticals. In earlier preclinical research, the same investigational vaccine robustly protected nonhuman primates against SARS-CoV-2, the virus that causes COVID-19. This investigational vaccine candidate was being tested in humans through a Phase 1/2a clinical trial in the U.S. and Belgium.

Vaccinated hamsters in the study did not experience severe COVID-19 symptoms. The researchers defined severe COVID-19 in hamsters as extensive pneumonia and lung inflammation, high amounts of coronavirus, and substantial weight loss.

The research team also found hamsters can develop severe illness and weight loss after becoming infected with a high dose of the virus that causes COVID-19. This indicates hamsters could be good models to evaluate how well potential vaccines protect against severe coronavirus. Previously studies involving other animal models have generally led to mild to moderate COVID-19 disease.