Previous Covid-19 infection provides some immunity for at least five months, but people may still carry and transmit the virus, according to a new study.
Experts have warned that a small number of those with immunity may still be able to carry the virus in their nose and throat and therefore have a risk of transmitting it to others.
The first report from Public Health England's (PHE) Siren study found that antibodies from past infection provide 83% protection against reinfection for at least five months.
This suggests that people who contracted the disease in the first wave may now be vulnerable to catching it again. Although reinfections in people with antibodies were rare, the researchers identified 44 potential reinfections among 6,614