The School of Biological Sciences Fall 2024 Seminar Series presents Dr. Jeffrey Townsend

When a pandemic starts, there are many factors that are unknown. Rapidly acquiring information becomes critical to pandemic response. Emphasis of what we don’t know is critical to advancing immediate priorities. However, in many cases, we may know more than might be assumed. I will discuss two examples where it was possible to use information and inference to inform pandemic uncertainties and guide public health decision-making: determining quarantine durations for detected cases and for international travel, and quantifying the durability of immunity against reinfection and breakthrough infection after vaccination. Our early identification of the benefit of a negative COVID-19 test on exit was cited by the CDC in their stipulation of a shorter quarantine with test, and our assessment of justifiable travel quarantines has markedly changed the conception of appropriate enforcement for public health. An oft-cited uncertainty of the early pandemic was the durability of immunity against reinfection, leading to the promulgation of an idea that perhaps sufficient infection would lead to herd immunity. We were able to show using viral antibody waning data from closely related human-infecting coronaviruses and their evolutionary relationships with SARS-CoV-1, MERS, and SARS-Cov-2 that the durability of immunity to reinfection is short, key information for public health interventions, and to further characterize the relative durability of immunity against breakthrough infection achieved by several major vaccines, and lastly to recently characterize the frequency of booster vaccination required to suppress infection given endemic transmission. These insights can be extended to future pandemics to enable increasingly rapid response upon identification of novel vectors of infection.

Hosted by William Ratcliff