As we move to ‘living with the virus’, it’s time to consider the balance of benefits and harms of asking people to quarantine
Ministers for the UK government have said the NHS Covid contact tracing app may need to be less sensitive, but is this a good idea when cases are rising so rapidly? Regardless of what is announced on 19 July, there will be a large wave of new cases, mainly in younger people; the latest ONS infection survey shows 16 to 24-year-olds have the highest infection rates, about 10 times more than in the over-50s. The link from infection to hospitalisations and deaths may have been weakened, but millions of contacts in quarantine implies major economic disruption and challenges to providing healthcare, let alone ruined holidays.
Quarantining contacts only reduces cases if (a) contacts are infected and (b) they isolate before infecting others. Since May 2020, NHS test and trace has reached more than 7.5 million close contacts and told them to self-isolate for 10 days. The benefit of this enforced inactivity is contestable: under 10% of contacts become lab-confirmed cases, and those who do may already have passed on the virus, as the median time to reach contacts after the initial case first reported symptoms is around four days.
