If you have been infected with COVID-19, you may have some protection against certain versions of the cold.

A new study suggests that previous COVID-19 infections reduce the risk of getting colds caused by less virulent coronaviruses, which could be the key to expanding COVID-19 vaccines.

“We think there will be a coronavirus epidemic in the future,” warned Dr. Manish Sagar, lead author of the study published Wednesday in the journal Science Translational Medicine. “Vaccines could be improved if we could replicate some of the immune responses that occur during natural infection.”

The study examined the COVID-19 PCR tests of approximately 5,000 people who sought medical attention between November 2020 and October 2021. After taking into account factors such as age, gender and pre-existing conditions, Dr. Sagar and his colleagues found that people previously infected with COVID-19 were about 50% less likely to suffer from a symptomatic cold caused by the coronavirus, compared to people who were, at the time, fully vaccinated and n had not yet been infected with COVID-19.

Several viruses cause colds; Coronaviruses are believed to be responsible for around one in five colds.

Researchers have linked protection against colds caused by coronaviruses to virus-killing cellular responses for two specific viral proteins. These proteins are not used in most current vaccines, but researchers propose adding them in the future.

“Our studies suggest that these may be new strategies for better vaccines that address not only current coronaviruses, but any that may emerge in the future,” said Dr. Sagar of Boston Medical Center.

Dr. Wesley Long, a pathologist at Houston Methodist in Texas, who was not involved in the study, said the results should not be seen as an attack on current vaccines, which target the spike protein found in the surface of the SARS-CoV-2 virus that causes COVID-19.

These vaccines, he said, “remain the best defense against severe COVID-19 infection, hospitalization and death.”

But he added: “If we can find targets that provide cross-protection between multiple viruses, we can either add them to specific vaccines or start using them as vaccine targets that would give us broader immunity from ‘only one vaccination. That would be really awesome. »