Most pandemic modelling is focused on the first part of the epidemic curve(s): reproduction numbers, doubling times, and interventions. Other notions such as the final size of an epidemic, or the transition from pandemic to endemic, have received less attention. However, the time has come to model the end-game. What is herd immunity? How effective do the vaccines need to be and what fraction of the population needs to be vaccinated? Why not let the kids run wild? In this talk, I will review the mathematics behind these notions in the context of the CoViD-19, make some ball-park estimates, and try to convince you that the notion of herd immunity as it is being applied to the coronavirus is not the same as its use for measles, polio, and smallpox.

James Watmough obtained his PhD in Mathematics with the Institute of Applied Mathematics at the University of British Columbia and is now a Professor in the Department of Mathematics and Statistics at the University of New Brunswick. He has been a member of the Canadian Centre for Disease Modelling http://www.cdm.yorku.ca/) since its inception and more recently, a member of the Canadian COVID-19 Math Modelling Task Force (http://www.fields.utoronto.ca/activities/Mathematical-Modelling-COVID-19). His research interests include mathematical modelling of ecological systems with a focus on the role of heterogeneity in the spread of infectious diseases, biological invasions, and more recently our immune response to coronavirus infections.

Website: www2.unb.ca/~watmough

Relevant code: https://github.com/jameswatmough/SLIARmodel