Have you tested negative for covid-19 despite being exposed to coronavirus? May have “immunological memory”


A new study in the UK may have revealed why some people are testing negative for covid-19 despite being exposed to the virus.

Research that monitored health professionals during the first wave in London found that some people have an “abortive infection”. In these cases, the virus enters the body, but is expelled by T cells early in the infection, leading to a negative result in PCR and antibody tests.

“We all know someone who was exposed but did not succumb to the infection. What we didn’t know was whether these individuals had actually managed to avoid the virus or if they had naturally expelled it before it was detected in routine tests,” explains Leo Swadling, immunologist and one from the main authors to the “The Guardian“.

Despite the high exposure, 58 of the study participants (about 15%) never tested positive for the virus. However, the blood samples showed a higher concentration of T cells present in the blood, compared to tests carried out before the outbreak and with people who had not been exposed to the virus.

Scientists believe this discovery could pave the way for the creation of new vaccines focused on these cells that could create longer-lasting immunity, over years instead of months as in the case of antibodies.

The study also suggests that some of these people already had an immunological memory of these cells, acquired through previous exposure to other viruses – namely seasonal flu – and that it protects them from covid-19.


Source: Expresso by expresso.pt.

*The article has been translated based on the content of Expresso by expresso.pt. If there is any problem regarding the content, copyright, please leave a report below the article. We will try to process as quickly as possible to protect the rights of the author. Thank you very much!

*We just want readers to access information more quickly and easily with other multilingual content, instead of information only available in a certain language.

*We always respect the copyright of the content of the author and always include the original link of the source article.If the author disagrees, just leave the report below the article, the article will be edited or deleted at the request of the author. Thanks very much! Best regards!