Singapore research : People who have never contracted covid may also have immunity

Publisher : Lianhe Zaobao

Ref : https://www.zaobao.com.sg/news/singapore/story20200717-1069726

Translation, editing : Gan Yung Chyan

                                / KUCINTA SETIA

The latest Singapore research has found that some healthy people who have not been infected with SARS-CoV-2 (or covi) already contain T cells that target the virus, which means that the local population has a certain degree of immunity to covi.

Whether these targeted T cells can effectively fight viruses remains to be further studied, but preliminary studies have concluded that people with these T cells can avoid serious illness.

Duke-NUS School of Medicine published research results yesterday. Among 37 healthy people, more than half of them contain immune T cells against covi.  These people have never been infected with covi, nor have they been infected with the severe acute respiratory syndrome coronavirus one (SARS-CoV-1, or SARS virus) that causes SARS.

According to research reports, healthy people with T cells targeting covi may have been infected with other coronaviruses, such as the coronavirus that causes the common cold, or unknown animal coronaviruses, to produce T cells.

T cells are white blood cells that specifically recognize viruses and are an important part of the immune system. A number of recent studies have found that people infected with covi can quickly produce T cells that attack the virus, and as time goes by, there are more and more T cells in the body. Researchers hope they can play an active role in responding to the novel coronavirus epidemic.

The author of the research report, Antonio Bertoletti, Professor of the Emerging Infectious Diseases Program at Duke-NUS  School of Medicine, said in an interview with Lianhe Zaobao that although SARS virus, SARS-CoV-2, Middle East respiratory syndrome virus, and the four human coronaviruses HKU1, OC43, BL63 and 229E are different coronaviruses, but some parts of the virus remain intact, so they are similar to T cells. This phenomenon is called cross-reactivity.

He pointed out that the so-called immunity, in addition to having immunity, also depends on whether the immunity can effectively protect a person. "Some data shows this. We need to do more to confirm whether the T cell response can provide protection."

The study also found that despite 17 years, 23 subjects who had been infected with SARS virus still had T cells against SARS virus in their bodies, and these T cells also had a strong crossover with SARS-CoV-2 reaction.

This research was conducted in collaboration with Duke-NUS School of Medicine, NUS Yang Luling School of Medicine, Singapore General Hospital, and the National Center for Infectious Diseases.