You Who Haven't Caught COVID-19, the Key to Saving Humanity? [Reading Science]

Scientists Focus on T Cells with 'Cross-Reactivity' in 'Super-Immune' Individuals
Key to Developing Vaccines and Treatments with Strong Durability Regardless of Variants

T-cell.

[Asia Economy Reporter Kim Bong-su] "You haven't even been vaccinated, yet you haven't contracted COVID-19? There might be a key in your genes that humanity can use to fight against COVID-19."

The number of confirmed COVID-19 cases in Korea has surpassed one-quarter of the total population. This is due to the continuous emergence of variants and the limitations of vaccine protection. The global situation is similar. Accordingly, experts are focusing on the ability of T cells, which have been confirmed to directly attack the virus regardless of mutations and have strong durability, possessed by so-called 'super immune individuals.'

According to Bloomberg on the 1st, as COVID-19 variants have continued to emerge over the past two years and infections have surged again in the United States, American experts have begun intensive research focusing on the infection avoidance ability of these 'super immune individuals.' In February, the U.S. Centers for Disease Control and Prevention announced that about 43.4% of Americans have COVID-19 antibodies. This means that more than 50% of people have not yet been infected with COVID-19.

The COVID-19 virus frequently mutates to evade the human immune system. The protection generated by vaccination also weakens over time. Because of this, it is difficult to determine how many people have immunity to COVID-19 at any given time. For example, the recently dominant Omicron variant provides immunity against the previous Delta variant after infection and recovery. However, the Omicron variant itself neutralizes the body's defenses formed by previous variants such as Alpha, Beta, Gamma, and Delta. Especially recently, as many people conduct COVID-19 tests at home and do not report the results, it has become difficult to accurately grasp the scale of infections. Consequently, the number of COVID-19 cases has not stopped increasing in many regions even two years after the pandemic began.

Experts are increasingly interested in uncovering the principles behind the 'super immunity' of people who have not yet been infected with COVID-19. In other words, they are focusing research on how 'super immune individuals' can eliminate the COVID-19 virus before it replicates in the body and before antibody production is triggered. In this regard, a research team at London College published a paper last November confirming that some healthcare workers in the UK were able to eliminate the virus upon exposure before producing antibodies. Some people previously infected with coronaviruses have natural immune cells (T cells) in their bodies that remember the virus and respond quickly, successfully eliminating it before antibodies are produced.

Notably, their T cells exhibited different behavior from those of COVID-19 infected patients. T cells produced by vaccination or COVID-19 infection attacked the spike protein of the virus, which undergoes mutations, but the T cells of super immune individuals targeted the internal structure of the COVID-19 virus. Scientists have named this ability of T cells to attack and eliminate the virus regardless of mutations as 'cross-reactivity.'

In fact, a pharmaceutical company called Gritstone Bio is conducting experiments based on these research results. Other studies have reached similar conclusions. One study investigating people who lived with COVID-19 patients but were not infected found that they had been exposed to coronaviruses in the past. In January, research also showed that children without COVID-19 antibodies possessed cross-reactive T cells. Leo Swadling, Professor of Immunology at London College, said, "Because T cells have a long lifespan, repeated vaccinations are not necessary," adding, "Studying super immunity could help us respond not only to Omicron but also to future variants that may arise."