IMMUNITY to Covid-19 may last no longer than a few months, according to recent studies.
Scientists have found that immunity to the virus is waning, and that the amount of patients producing protective antibodies is declining.
Research by Imperial College London estimates that 4.4% of adults had immunity to Covid-19 in September.
This is down from 6% from studies taken in June, and 4.8% from studies taken in August.
Professor Paul Elliott, director of the programme at Imperial, from the school of public health, said: "Our study shows that over time there is reduction in the proportion of people testing positive for antibodies against the virus that causes Covid-19.
"It remains unclear what level of immunity antibodies provide, or for how long this immunity lasts.
"If someone tests positive for antibodies, they still need to follow national guidelines including social distancing measures, getting a swab test if they have symptoms and wearing face coverings where required."
It appears that the human body may only produce coronavirus antibodies for a set amount of time, meaning that it doesn't develop a permanent resistance to the virus.
Around 365,000 adults took part in the studies, which tested for the prevalence of coronavirus antibodies in patients living in England three times over a three month period.
Antibody levels fell on a average by 26.5% overall over the three months.
Graham Cooke, professor of infectious diseases at Imperial, said: "The big picture here is that after the first wave [of coronavirus], the great majority of the country still did not have evidence of protective immunity.
"So although we are seeing a decline in the proportion of people who are testing positive, we still have a great majority of people who are unlikely to have been exposed.
"So the need for a vaccine is still very large if you want to try and get a large level of protection in the population."
