Large-scale deployment of safe and durably effective vaccines can curtail the COVID-19 pandemic. The COVID-19 vaccines currently in use were approved on the basis of efficacy and safety data from phase 3 trials with a median follow-up time of only about two months. Because of crossover, the phase 3 trials provided little information about the efficacy of these vaccines beyond 6 months. Typically, estimates of vaccine efficacy over broad time intervals are reported, which are not informative about the level of waning at the end of the observation period. Observational studies can potentially provide information about long-term vaccine effectiveness, but they are more difficult to be analysed. In this talk, I will discuss how to properly measure and estimate vaccine efficacy/effectiveness as a function of time elapsed since vaccination while properly accounting for changing transmission rates over calendar time. I will present results on the long-term effectiveness of the Pfizer, Moderna, and Janssen vaccines against Covid-19, hospitalization, and death in the United States.

Who is this event intended for? Statisticians working on Vaccines or related topics to COVID-19.

What is the benefit of attending? To learn how to evaluate the duration of protection of COVID -19 vaccines and about the performance of blinded and unblinded crossover designs in estimating long-term vaccine efficacy.