In patients who have confirmed COVID infections, many don’t have detectable levels of antibodies in their blood, yet these same patients do have T-cells with receptor memory specific to the COVID virus.
T-cells may hold the key to long lasting immunity against this virus.
As antibodies wane over time, research suggests T-cells confer longer lasting protection from COVID and its variants. Although antibody immunity has received the bulk of attention in COVID coverage, evidence points to a major, albeit under-reported, role of T cells in the resolution of COVID. Similar coronaviruses – specifically SARS-CoV-1 and MERS – tend to only elicit a short-lived humoral (antibody) response and initial reports suggest SARS-CoV-2 behaves similarly.
Said succinctly, the antibodies fade over time but T-cell memory lasts much longer.
The data is compelling: A group of people who had been exposed to the SARS-CoV-2 virus were tested for both an antibody response and T-cell response to the virus. Most asymptomatic COVID cases showed a strong T-cell response but only about 60% of them had detectible antibodies in their blood. In fact, over 90% of the group labeled “exposed asymptomatic” had detectible T-cell responses.
This suggests that “asymptomatic infections may be more common than current data suggest” according to the authors of this study.
Interestingly, a small fraction of samples collected in mid-2019 prior to the COVID-19 outbreak, and thus considered people with no exposure to the SARS-CoV2 virus, revealed some T-cell memory to the virus. Since there are four known coronaviruses that circulate seasonally in the general population and are known causes of a common cold (HCoV-OC43, HCoV-229E, HCoV-NL63, and HCoV-HKU1), this suggests that T-cell immunity to one coronavirus may extend to other coronaviruses. This is good news as some people may have some immunity from past infections with other coronavirus strains, and may partially explain the disparity in symptoms for different people.
The marvelous intelligence of a well-functioning immune system is illustrated in this medical paper. The exquisite “redundancy and diversity in the immune system” confers protection from viruses even if one branch of the immune system is not as strong as the other branch. In other words, T-cell immunity and B-cell immunity aren’t in competition – they work together. The paper is appropriately titled “COVID-19 makes B cells forget, T cells remember.”
SpectraCell measures T-cell function in a test called the Immunidex, which is part of its more comprehensive Micronutrient Test. Beginning in 2021, the Immunidex can be ordered as a standalone test called the Immunidex Screen.
(Cell, October 2020)
LINK to FREE FULL TEXT COVID-19 Makes B Cell Forget, but T Cells Remember
