The virus that causes the common cold might offer some level of protection against Covid-19 infection, according to a new study. But vaccination is still the best way to stay protected. 

Researchers found the human rhinovirus (common cold virus) triggers an innate immune response that seems to block the Covid-causing virus – known as SARS-CoV-2 – from multiplying in cells of the respiratory tract. 

What’s more, the research team found that this interaction between the two viruses could have a population-wide effect – and an increasing prevalence of colds could actually reduce the number of new Covid-19 cases.

Human rhinoviruses are the most widespread respiratory viruses found in people. Previous research has shown interactions between rhinoviruses and other respiratory viruses can affect the type and severity of infections, and the way in which they infect and circulate around groups of people.

Viruses only infect a small number of cell types within the body, and respiratory viruses typically infect cells within the respiratory tract.

In the study, the researchers infected human respiratory cells with SARS-CoV-2 in the lab, recreating the cellular environment in which infections normally occur.

They then studied the replication of SARS-CoV-2 in these cells, both in the presence and absence of rhinovirus.

They discovered the common cold virus triggers an initial immune response in human respiratory cells which then blocks the replication of SARS-CoV-2.

Professor Pablo Murcia, from the MRC-University of Glasgow Centre for Virus Research, explained: “This means that the immune response caused by mild, common cold virus infections, could provide some level of transient protection against SARS-CoV-2.”

He even suggested this could potentially block transmission of SARS-CoV-2 and reduce the severity of Covid-19. Although for now he warned that vaccination is our best method of protection against the virus.

The research was published in the Journal of Infectious Diseases and funded by the Medical Research Council (MRC).

Prof Murcia said the next stage will be to study what is happening at the molecular level during these virus to 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,” he said.