Lightening the viral load to lessen covid-19 severity
Stephen Burgess, David W. Smith, Julia C. Kenyon, Dipender Gill
Abstract
Although the number of positive tests for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) across many European countries has risen sharply in recent weeks, increases in the number of hospital admissions and deaths from covid-19 have not been as steep. The case fatality rate (the proportion of deaths per positive test) in the UK was lower in May and June than in March and April 1 and seemed to steadily decline throughout July and August. 2 Reductions were also observed in the early stages of the outbreak across many countries. 3 Case fatality rates have varied in different countries, with relatively lower estimates observed in several African countries. 4 Why have case fatality rates decreased, and how does this relate to measures used to control the epidemic?