Recent studies show that recovery from the common flu can also prevent infection from the coronavirus because of higher levels of T cells, now recognized as a layer of protection against COVID-19, present in the body of the recovered person.
Scientists involved in a recent study assessed close contacts of those newly diagnosed with COVID-19 to pinpoint when they were first exposed. They found that those who tested negative for COVID-19 had higher cross-reactive T cell levels.
Dr. Rhia Kundu, the lead author of the study, said that being exposed to the virus does not always result in infection, and they want to understand why.
The team took blood samples from volunteers within days of being exposed to SARS-CoV-2 to allow researchers to determine their T cell levels. Household contacts who did not test positive showed that they had significantly higher levels of pre-existing coronavirus-fighting T cells.
Further, the team found out that the high levels of pre-existing T cells created by the body when infected with other human coronaviruses like the common cold can protect people against the COVID-19 infection. (Related: The common cold can protect people against coronavirus, study finds.)
Another author, Ajir Lalvani, said that the study provides the clearest evidence that T cells induced by the common cold can play a protective role against infections, adding that the T cells provide protection by attacking proteins within the virus instead of the spike protein on its surface.
Lalvani said that the spike protein is under intense immune pressure from vaccine-induced antibodies, which could drive the evolution of vaccine mutants. In contrast, by targeting proteins internally with the protective T cells, the virus mutates less. Lalvani, however, added that "they are highly less conserved between the various SARS-CoV-2 variants, including omicron."
Further, Lalvani noted that new vaccines that include conserved, internal proteins would induce broadly protective T cell responses that should protect against current and future variants. (Related: Professor says covid is becoming "just another cause of the common cold.")
The available vaccines have proven to be less effective against the omicron strain, including against severe diseases. While booster shots restore some of the lost protection, early data shows that the boost drops its effectiveness against infection after it is administered into the body, and it is not yet clear whether or not the booster shots could maintain its protection longer.
Some academics not involved in the study warn that it could be a mistake to think that anyone who has had a cold caused by a coronavirus is protected against COVID.
An associate professor in cellular microbiology at the University of Reading, Dr. Simone Clarke, noted that while the study adds to findings on how the immune system can help fight the virus, it should not be "overinterpreted."
He noted that it is "unlikely" that the 150,000 people who have died within a month of testing positive for COVID never had a cold caused by a coronavirus. He said that coronaviruses only account for 10 to 15 percent of colds, and it is a grave mistake for anyone to think that they are protected once they develop a cold.
"There is no measurement of how much protection the reported effect gives people," he said. "A link is only hinted at, it has not been proven conclusively."
Watch the video below to learn more about how the common cold could fend off COVID.
This video is from the "WGON" channel on Brighteon.com.
Read more about COVID-19 updates at Pandemic.news.