Your immune system activates T-cells when you catch a cold. They help neutralize the virus to stop it, so you eventually regain health. If you’ve got the T-cells active from fighting a cold, their presence may help disable the SARS-CoV-2 virus (the coronavirus that leads to COVID-19).
Vaccination, of course, remains the best defense against COVID-19 infection and severe symptoms.
Researchers wanted to know why some people get sick when exposed to the virus while others don’t. They found that high levels of pre-existing T-cells, like those brought on from other coronaviruses like a cold, played a role.
This finding could lead to potential improvements on existing COVID vaccines that might better target viral variants, like omicron.
The study started in September 2020, long before many people were vaccinated against COVID. It only involved 52 people, but the results are quite intriguing. The team looked at 52 people who had lived with somebody who’d been exposed to the virus.
Each participant took PCR tests after the exposure, then 4-7 days later. They also had blood samples taken between one and six days of exposure so researchers could analyze T-cells from previous infections.
Researchers found that the 26 people who did not become infected with SARS-CoV-2 had significantly higher levels of the cross-reactive T-cells (that indicate a recent cold) than the 26 people who were infected.
Now, this doesn’t mean that you should be out there trying to catch a cold to boost immunity from omicron or future COVID variants. But it does suggest the power of an active immune system and a potential new method to target vaccines.