The COVID-19 pandemic caused by the deadly SARS-CoV-2 coronavirus has killed nearly 7 million people over the past three years. However, even after repeated infections, some people remain symptom-free. Researchers at the University of California, San Francisco (UCSF) found that one in five people who do not experience symptoms after being infected with the SARS-CoV-2 virus carries a variant of the HLA-B*15:01 gene. This discovery may help develop more effective vaccines and treatments.
HLA genes play an important role in maintaining the human immune system. They help immune cells recognize and attack infections and diseases. Researchers found that in people with the HLA-B*15:01 gene who had never been infected with a virus, immune cells reacted to fragments of the SARS-CoV-2 protein. This suggests that these people developed immunity to the virus after exposure to other infections.
Studies show that about 20 percent of SARS-CoV-2 infections are asymptomatic. Therefore, learning more about this phenomenon could help scientists fight a disease that continues to claim lives around the world.
Key findings of the study:
– One in five people without symptoms after SARS-CoV-2 infection carries a variant of the HLA-B*15:01 gene.
– In people with the HLA-B*15:01 gene who had never been infected with the virus, immune cells reacted to fragments of the SARS-CoV-2 protein.
– Approximately 20 percent of SARS-CoV-2 infections are asymptomatic.
These results indicate that genetic data can be used to predict the development of COVID-19 symptoms and to develop new treatments and prevention methods. The presence of the HLA-B*15:01 gene doubles the likelihood of asymptomatic disease, and two copies of the gene increase the likelihood of asymptomatic disease eightfold.
Biochemist Stephanie Gras of La Trobe University in Australia notes that studying asymptomatic infection may help develop new ways to increase defense against COVID-19. Mimicking the immune “shield” seen in symptom-free people could be key to successfully fighting the pandemic.
