They include, first, the use of clinical diagnosis, rather than laboratory testing, where there is a high probability, due to close contact with confirmed cases, that symptomatic people are positive; secondly, continued antiviral treatment of all those who have the virus but more targeted use of antiviral prophylaxis, based on local risk assessment and limited to contacts considered most at risk of contracting the virus—in practice, mainly household or household-like contacts, or, in a school context, those at surrounding desks; and thirdly, the restriction of contact follow...