People previously infected with COVID-19 can have immunity for up to five months afterwards, but could still pass it on to others, England’s health agency has said.

Public Health England said it had been testing tens of thousands of health workers across Britain since June for antibodies.

Its researchers found that people can be up to 83 per cent protected against the virus after being previously infected with Covid-19. The protection then appears to last for five months.

Between June 18 and Nov. 24, scientists detected 44 potential re-infections, two “probable’’ and 42 “possible’’ reinfections  out of 6,614 participants who had tested positive for antibodies.

But early evidence from the next stage of the study suggests some people carry high levels of the virus and could transmit it to others.

Prof. Susan Hopkins, senior medical advisor at Public Health England and leader of the study, said: “We now know that most of those who have had the virus, and developed antibodies, are protected from reinfection, but this is not total and we do not yet know how long protection lasts. Crucially, we believe people may still be able to pass the virus on.’’

The team has not yet investigated immune responses from the COVID-19 vaccines, which Britain began rolling out in November.

They will investigate people’s bodily reactions to vaccines later in the year.

According to the latest figures from the British government, more than 3.2 million people have tested positive for COVID-19 in the four nations since the outbreak began. (dpa/NAN)