New variants of Covid-19 mean any immunity within the population through vaccination may never completely eradicate coronavirus, experts have said.
Danny Altmann, professor of immunology at Imperial College London, said that Covid may never die out because mutations in the virus could affect the efficacy of vaccines.
And a Government scientific adviser said that coronavirus is unlikely to be eradicated entirely but the “nature of the virus” means it could become a seasonal infection.
Andrew Hayward, of University College London’s Institute of Epidemiology and Health Care, who sits on the Government’s New and Emerging Respiratory Virus Threats Advisory Group (NERVTAG), told BBC Radio 4’s Today programme that Covid-19 would likely continue to mutate, meaning herd immunity was unlikely.
Asked on Times Radio whether coronavirus could “die away” once enough people have antibodies – either through having caught the virus previously or via vaccination – Professor Altmann said: “That’s still kind of true.
“More vaccination means more people carrying antibodies means fewer susceptible people, which means fewer lungs for the virus to be in, which means less pandemic.
“So, it hasn’t all gone out of the window. But nobody said this virus had to be simple.”
Despite more than 39 million people – three quarters of UK adults – now being double-jabbed, scientists say variants can allow the virus to continue to spread and make people ill.
Professor Altmann said: “There’s Delta at the moment, there may well be other worse ones coming round the curve, and they impact the effectiveness of the vaccines and change their calculations.”
The Delta variant is currently the most dominant strain of Covid-19 in the UK and data suggests double vaccinated people are more likely to experience symptoms from this variant than earlier ones.
Professor Hayward said: “I think the nature of this infection and the nature of the vaccines is such that the level of immunity that is achieved is not enough to consider that.
“If someone could come up with a vaccine that was not only 95 per cent protective against severe disease but 95 per cent protective against infection then, yes, we would stand a chance of eradicating it.”
He added: “I think it is a pretty distant prospect and we need to get used to the concept that this will become what we call an endemic disease rather than a pandemic disease.
“A disease that is with us all the time probably transmits seasonally a bit like influenza, where we see winter outbreaks.”
Oxford Vaccine Group director Professor Sir Andrew Pollard told MPs yesterday that achieving herd immunity was “mythical”.
Giving evidence to the all-party parliamentary group on coronavirus, Professor Pollard said: “We know very clearly with coronavirus that this current variant, the Delta variant, will still infect people who have been vaccinated and that does mean that anyone who’s still unvaccinated, at some point, will meet the virus.”