Omicron's Two-Thirds Say They've Had Covid Before.

Two-thirds of those who have recently been infected with the Omicron variant report they have previously had Covid.

The findings came from React, a big, ongoing study in which thousands of participants in England were swab-tested.

More research is needed to determine how many are true reinfections, but the findings do reveal which groups are more likely to catch Covid again.

Healthcare workers and families with children or several people living under one roof are among them.

In total, over two million people have been tested as part of the project.

The most recent findings, for the first two weeks of 2022 (round 17), are based on around 100,000 polymerase chain reaction (PCR) tests that were sent to participants and then returned.

Around 4,000 people tested positive, the greatest number since the outbreak began.

When a sample of them was sequenced to see what type of Covid was to blame, it turned out that nearly all of them were Omicron, the highly infectious form first discovered in South Africa and responsible for a large winter wave of infections in the UK.

It's unclear how many of the participants who tested positive had received all of their vaccinations.

Two doses provide minimal protection against Omicron infection, although they do provide some protection against severe disease.

However, since Omicron's arrival, booster dosages have been rapidly distributed to supplement people's protection.

Two out of every three infected volunteers (65%) stated that they had previously tested positive for Covid.

It's possible that many of these were reinfected.

Although, in other cases, the most recent PCR testing may be catching up ancient viral traces.

According to some estimations, one out of every ten Omicron cases could be reinfected.