Does the presence of Covid-19 antibodies in your blood mean you are immune to the virus?

According to guidance published by many health authorities, including the UK’s Department of Health and Social Care in July, there is no strong evidence to suggest that those who’ve had the virus and produced antibodies are immune.

In other words, receiving a positive antibody result does not mean a person is immune or can’t pass on the virus to others. But in this past week, the UK’s Advertising Standards Authority (ASA) has upheld complaints of misleading advertising by three clinics in this regard, as the country grapples with a second wave...