My son has been riding out America's COVID-19 summer with extended family in the Hamptons – certainly a safer, more pleasant place to hibernate than New York City. But with winter approaching and the second wave rampant, his aunt politely suggested it was time for a young man who likes to party to take a COVID-19 test.

I was astonished not so much that he was negative but that it took only 15 minutes to get the result. That’s because the US, like Europe and Asia but unlike Australia, is making greater use of rapid antigen tests. These “point-of-care” tests still require the same uncomfortable nasal swabs but are not as accurate as the “gold standard” of PCR (polymerase chain reaction) testing. So instead of a near 100 per cent “sensitivity” or accuracy rate in detecting the virus, most offer only the high 80 per cent range. That typically translates into 10-20 per cent of people who still can’t be sure they don’t have the virus.