Editorial: How can we reach a level of herd immunity that will protect us from COVID-19?

Epidemiological theory teaches us that a microbial agent introduced into a population stops circulating when the proportion of the population that is immune to that agent is higher than or equal to 1-1/R0, where R0 is the much-discussed reproduction rate, the number of secondary cases generated by each infected person in a non-immune population in the absence of control measures. In France, where R0 was estimated as 3 before the lockdown (Salje et al., Science, 2020), that means that 67% of the French population need to be immune to the novel coronavirus for the virus to stop circulating on a large scale.

In a Comment published by the journal Nature Reviews Immunology, Arnaud Fontanet (Institut Pasteur/Cnam) and Simon Cauchemez (Institut Pasteur/CNRS) explore the conditions affecting the application of the formula used to calculate the level of herd immunity needed to offer widespread protection..

Find out more (in French)