High levels of T-cells from common cold coronaviruses can protect against COVID-19, suggests a study from Imperial College London.

The study was started in September 2020 and evaluated the levels of cross-reactive T-cells which were produced by prior episodes of common colds in 52 household contacts of positive COVID-19 cases shortly after exposure. Investigators assessed if they would develop infection. Twenty six individuals who did not develop the infection were found to have significantly higher levels of these T-cells compared to those who contracted the infection. 

Dr Rhia Kundu, study author, said that high levels of pre-existing T cells, generated when infected with other human coronaviruses such as the common cold, appear to protect against COVID-19 infection. The study is published in Nature Communications… (NDTV – Reuters, January 10, 2022)