People who’ve recently recovered from a cold may enjoy some protection against coronavirus, scientists have claimed.
Lab studies by the University of Glasgow researchers found the common cold triggers the release of antibodies which also target Covid in the nose and lungs.
The researchers said this means someone who has recently had a runny nose may be less likely to become sick with Covid or catch it in the first place.
But this protection likely only lasts a short period of time because of how quickly immunity against the family of viruses that cause the cold last.
Professor Pablo Murcia, from the MRC-University of Glasgow Centre for Virus Research, said: ‘Our research shows that human rhinovirus triggers an innate immune response in human respiratory epithelial cells which blocks the replication of the Covid-19 virus.
‘This means that the immune response caused by mild, common cold virus infections, could provide some level of transient protection against SARS-CoV-2, potentially blocking transmission of SARS-CoV-2 and reducing the severity of Covid-19.
‘The next stage will be to study what is happening at the molecular level during these virus-virus interactions, to understand more about their impact on disease transmission.
‘We can then use this knowledge to our advantage, hopefully developing strategies and control measures for Covid-19 infections.
‘In the meantime, vaccination is our best method of protection against Covid-19.’
Antibodies – substances produced by the body to defend against infections – made against human rhinoviruses fade after only a few months.
Covid-specific antibodies are thought to last at least six months, but other studies have suggested they should remain in most people for more than a year.
Because Covid is such a new virus, scientists are still unsure how immunity from natural infection or vaccination lasts.
It follows on from a similar study last year which also suggested antibodies created by the immune system during common cold infection may also provide some protection against Covid-19.
The paper, by researchers at the Francis Crick Institute and University College London, also found some people have coronavirus antibodies despite never having the virus.
The researchers studied antibodies circulating in blood samples taken before the coronavirus pandemic started, dating back to 2011.
Of more than 300 people who never had Covid-19 found that around five per cent of adults have these versatile antibodies. However, in a group of under-16s, this percentage shot up to 44 per cent.
Scientists were currently unable to explain why the presence of these cross-virus antibodies differs in adults and children.