"Is It Safe to Be Next to a COVID-19 Patient?"... Existence of 'Super Gene' That Prevents Infection

A24-type Antigen Carriers Show Active 'Killer T Cell' Response

Citizens receiving vaccinations. Not related to the article.

[Asia Economy Reporter Na Ye-eun] There are people who do not get infected even when exposed to COVID-19. Recently, research on the so-called 'Never Covid cohort,' individuals possessing specific genes that show strong immune responses to COVID-19, has been increasing.

According to foreign media, Imperial College London (ICL) in the UK has published a new study showing that people with high levels of 'T cells,' a type of immune system cell, in common cold-related coronaviruses have a lower likelihood of being infected with 'SARS-CoV-2.'

Through this, the research team concluded that the rate of transmission to other members within a household with a COVID-19 positive patient is surprisingly not very high.

The researchers directly exposed 36 healthy men and women aged 18 to 30 to the COVID-19 virus and observed them in a controlled environment for two weeks, finding that only half of the participants, 18 people, tested positive.

Dr. Liha Kundu, the first author of the study, explained, "Exposure to the SARS-CoV-2 virus does not always result in infection," adding, "We found that high levels of T cells produced in the body during COVID-19 infection can protect against the disease."

Professor Danny Altman, who led the study, said, "There has been ongoing curiosity about why people respond differently in the same COVID-19 environment, and we concluded that it is related to specific genetic factors," adding, "Certain genes definitely confer resistance to COVID-19, and even if infected, the likelihood of being asymptomatic is high."

Image of coronavirus. /Photo by Yonhap News

The key genetic factor that global researchers have focused on is the Human Leukocyte Antigen (HLA). This is one of the tissue compatibility antigens, and its form is determined by genes. The scientific consensus is that people with certain types of HLA who have had colds in the past show strong immune responses to COVID-19.

COVID-19 is a virus in the 'SARS-CoV' family, similar to the common cold. This is why many scientists have paid attention to the possibility of 'cross-immunity' between COVID-19 and cold coronaviruses.

The gene strongly associated with COVID-19 resistance identified so far is the 'A24 type' Human Leukocyte Antigen. People possessing this antigen showed active responses of 'killer T cells' that destroy infected cells when exposed to COVID-19. This means that T cells neutralized the COVID-19 virus through immune memory reacting to specific spike protein regions of the cold coronavirus.

This antigen is a genetic factor more common among Asians, which supports the reason why Asian countries have fewer confirmed cases compared to the US and Europe. On the other hand, there is also analysis that individuals with the Human Leukocyte Antigen 'DRB1*1302' are more vulnerable to COVID-19 infection.