New study uncovers gene that protects from COVID-19

The immune response to COVID-19 has become a topic of great interest, particularly in understanding why some individuals remain unaffected while others fall ill. A recent study published in Nature delved into this subject, uncovering a potential explanation. Researchers conducted a unique challenge trial where young and healthy unvaccinated volunteers, who had never contracted COVID-19, were intentionally exposed to the virus. Surprisingly, only six out of the 16 participants became sick. This is prepared by SSP.

Initially viewed as a setback, the researchers recognized this as a valuable opportunity to investigate the immune responses of those who successfully resisted the infection. Of particular interest were the individuals with elevated activity of a lesser-known gene called HLA-DQA2, which is associated with immunity. Those who did not get sick demonstrated either no presence of the virus or temporary infections that quickly resolved. The former group displayed subtle but widespread changes in specific immune cells, while the latter exhibited a strong interferon response in their nasal passages within 24 hours after exposure. Interferons play a role in alerting the immune system to viral threats and attracting cells that combat the infection.

Intriguingly, participants who did fall ill took approximately five days to generate a similar interferon response, allowing the virus more time to replicate and spread. This disparity indicates that a rapid and localized immune activity at the site of infection could potentially hinder the establishment of the virus. Additionally, it was surprising to discover that the interferon activity was detected in the blood of those who became sick before signs appeared in their noses, contrary to initial expectations.

Reasons behind why some participants experienced transient infections while others did not remain unclear. However, both groups exhibited increased activity of the HLA-DQA2 gene before exposure, present in specialized immune cells involved in pathogen detection. Previous studies have suggested a connection between this gene and milder COVID-19 outcomes, potentially enabling the identification of individuals susceptible to infection based on their gene signatures.

It is important to note that the challenge trials were conducted in 2021, and the landscape has significantly changed due to widespread immunity from infection and vaccination. Consequently, the immune responses of the general population are likely to differ from those observed in this study. To obtain more diverse and comprehensive insights, future research with a larger and more varied participant pool, including individuals of different ages, would be invaluable.