Omicron: How do prior infections affect covid-19 risk from new variants?

Many people all over the world have now had one infection with covid-19 – how does that affect their future chance of a second round with the coronavirus?



Health



8 December 2021

A healthcare worker performs laboratory tests which detect immunoglobulin class G (IgG) antibodies to SARS-CoV-2 virus in blood at a medical centre of the INVITRO private healthcare company. Peter Kovalev/TASS (Photo by Peter KovalevTASS via Getty Images)

A healthcare worker does tests that detect antibodies to the coronavirus

Peter Kovalev/TASS via Getty Images

For the past year, there has been great interest in measuring how much protection the covid-19 vaccines give against infections and severe illness – and now the focus has turned to how the vaccines will fare against the new omicron variant. But there is another question about immunity that is relevant: how much protection is provided by a previous covid-19 infection?

Two years after the pandemic began, there have been about 250 million confirmed coronavirus infections around the world, although the …

Article amended on
9 December 2021

We clarified that some people with prior infections made no detectable antibodies against the virus