Prof. Mats Julius Stensrud on:

“Causal Inference for Better Control of Communicable

When facing infectious diseases, healthcare professionals
must make decisions under uncertainty. Certain considerations are frequently
recurring in this process. Knowing whether a vaccine’s effect wanes is
important for determining the timing of seasonal flu shots or assigning
COVID-19 boosters. Understanding whether a vaccine has heterogeneous effects on
different subtypes, such as Malaria variants, has implications for the
development of new treatments. Whether vaccinating a subgroup of individuals is
sufficient to reach herd immunity, due to spill-over effects, shapes public
health policies. Although the previous plain English sentences might seem
clear, I will argue that terms like “waning”, “heterogeneous effects”, and
“spill-over” are ambiguously interpreted. I will then propose ways to clarify
these terms based on theory and methods for causal inference. Using Malaria,
HIV, influenza, and COVID-19 as illustrative examples, I will show that these
clarifications matter in practice. In particular, I will leverage the
clarifications to define new treatment effects in vaccine settings, which sometimes
justify existing analytic approaches and also motivate new methods that are
feasible to implement.

Monday, 20 January 2025, 6:45 pm – 7:45 pm

Venue: Cinema Wengen