Prospects for a safe COVID 19 vaccine
Prior vaccine development experiences do not raise concerns about vaccine associated enhanced disease for COVID 19 vaccine candidates. Rapid development of an efficacious vaccine against the viral pathogen severe acute respiratory syndrome coronavirus 2 (SARS CoV 2) the cause of the coronavirus disease 2019 (COVID 19) pandemic, is essential, but rigorous studies are required to determine the safety of candidate vaccines. Here, on behalf of the Accelerating COVID 19 Therapeutic Interventions and Vaccines (ACTIV) Working Group, we evaluate research on the potential risk of immune enhancement of disease by vaccines and viral infections, including coronavirus infections, together with emerging data about COVID 19 disease. Vaccine associated enhanced disease has been rarely encountered with existing vaccines or viral infections. Although animal models of SARS CoV 2 infection may elucidate mechanisms of immune protection, we need observations of enhanced disease in people receiving candidate COVID 19 vaccines to understand the risk of immune enhancement of disease. Neither principles of immunity nor preclinical studies provide a basis for prioritizing among the COVID 19 vaccine candidates with respect to safety at this time. Rigorous clinical trial design and postlicensure surveillance should provide a reliable strategy to identify adverse events, including the potential for enhanced severity of COVID 19 disease, after vaccination.
Science Translational Medicine