Theoretical novel COVID-19 vaccination risk of rare and severe adverse events versus COVID-19 mortality

Victor, Grech; Neville, Calleja

COVID-19 continues pandemic and researchers and companies are racing to develop effective vaccines with currently (September 2020) over 320 vaccine candidates, 32 of which are in clinical trials that plan to enroll >280,000 volunteers from >470 sites in 34 different countries. Vaccines are given to healthy multitudes and for this reason, they must adhere to high safety standards Many question the safety of vaccines developed with the current alacrity, commonly citing potential hypothetical and unknown (and indeed unknowable) side effects. This brief paper will outline the risk of such hypothetical events after a vaccine has gone through the appropriate testing phases and will compare this to estimated death rate from COVID-19 after factoring in asymptomatic cases, using a variety of scenarios and working with estimates of population, case and infection fatality ratios (analysed as Population Fatality Rate, Infection Fatality Ratio and Case Fatality Ratio). Even after factoring in up to 80% of individuals testing positive COVID-19 being asymptomatic, an effective vaccine that completes phase 3 trials having been administered to 20,000 individuals with very few (≤2) or no serious effects is well worth taking.