This study was undertaken for vaccine research. Also, there have been previous studies done that have shown the common cold Tcells protect against Covid-19. Our immune system is clearly very efficient and effective.
A new study, published in Nature Communications and led by Imperial College London researchers, provides the first evidence of a protective role for these T cells. While previous studies have shown that T cells induced by other coronaviruses can recognise SARS-CoV-2, the new study examines for the first time how the presence of these T cells at the time of SARS-CoV-2 exposure influences whether someone becomes infected.
The researchers also say their findings provide a blueprint for a second-generation, universal vaccine that could prevent infection from current and future SARS-CoV-2 variants, including Omicron.
Dr Rhia Kundu, first author of the study, from Imperial’s National Heart & Lung Institute, says: “Being exposed to the SARS-CoV-2 virus doesn’t always result in infection, and we’ve been keen to understand why. We found that high levels of pre-existing T cells, created by the body when infected with other human coronaviruses like the common cold, can protect against COVID-19 infection.
While this is an important discovery, it is only one form of protection, and I would stress that no one should rely on this alone. Instead, the best way to protect yourself against COVID-19 is to be fully vaccinated, including getting your booster dose.”
The study began in September 2020 when most people in the UK had neither been infected nor vaccinated against SARS-CoV-2. It included 52 people who lived with someone with PCR-confirmed SARS-CoV-2 infection and who had therefore been exposed to the virus. The participants did PCR tests at the outset and 4 and 7 days later, to determine if they developed an infection.
Blood samples from the 52 participants were taken within 1-6 days of them being exposed to the virus. This enabled the researchers to analyse the levels of pre-existing T cells induced by previous common cold coronavirus infections that also cross-recognise proteins of the SARS-CoV-2 virus.
Cross-reactive memory T cells associate with protection against SARS-CoV-2 infection in COVID-19 contacts’ by Kundu et al published today in Nature Communications: https://www.nature.com/articles/s41467-021-27674-x