Getting Covid-19 might not give you a long-term immunity, an infectious disease expert has warned.
Professor David Heymann said antibodies caused by contracting some viruses can wear off over time, which is why some vaccinations need a “booster” jab every few years.
During an online briefing for the Chatham House think tank, he said: "We know that antibodies from other coronavirus infections have a short-lived capability of providing immunity.
“So if a person is carrying an antibody to, say, coronavirus x and they've had a cold and that's what's caused this antibody, they could next year have a cold from the same coronavirus x and not be protected."
A world-class infectious epidemiologist, Professor Heymann was the World Health Organisation's (WHO) assistant director-general for health security and environment and representative of the director-general for polio eradication.
As the WHO’s Executive Director of Communicable Diseases, he headed the global response to SARS.
Professor Heymann went on: "In some coronaviruses the antibodies decrease and they permit another infection of the same organism.
"We don't know yet in the new coronavirus which causes Covid-19 whether or not that coronavirus does cause long-lasting immunity, and therefore we can't make too many assumptions.
He added: "It would be nice to say 'if I have antibodies I feel a little bit safer in going back into the public', and I think we would all do that. I would do that as well.
"But with the caveat that I don't understand exactly how long that immunity will last and I must pay attention to what's going on in science to know that."
But he said people who have had the virus could at least begin to work, depending on “what a country feels its risk tolerance is.”