Novel Coronavirus SARS-CoV-2 (50047466123)

What is the cause of asymptomatic COVID-19 cases?

The study led by researchers at University of California San Francisco, published in Nature on July 19, 2023, provides the first evidence of a genetic basis for asymptomatic SARS-CoV-2 infection.  Individuals who contract COVID-19 but remain symptom-free are more than twice as likely to carry a specific gene variation. The genetic mutation, HLA-B15:01, common in about 10% of the study’s population, doesn’t prevent virus infection but remarkably prevents the development of symptoms. The research identifies the HLA-B15:01 variant as a key factor in solving the mystery of asymptomatic COVID-19 cases, with 20% of asymptomatic individuals carrying it compared to 9% with symptoms. The study, focusing on unvaccinated donors, finds that risk factors for severe COVID-19 don’t play a role in asymptomatic cases. The HLA-B*15:01 gene’s ability to recognize and respond to COVID-19, facilitated by T-cell memory, suggests potential targets for drug and vaccine development. The collaboration with La Trobe University delves into the concept of T-cell memory, highlighting the immune system’s ability to recognize SARS-CoV-2 due to exposure to similar peptides in seasonal coronaviruses. The research opens avenues for promoting immune protection against SARS-CoV-2 in future vaccine or drug development.

Recently in AP Biology, my class learned about the intricate mechanisms of the immune system.  This research directly connects to our learning of the immune system, more specifically memory cells which are highlighted in the article as a key piece of how the HLA-B15:01 gene functions.  T memory cells are cells which are responsible for recognizing and responding to all previous infections.  As previously mentioned, La Trobe University found that the HLA-B15:01 gene recognizes COVID-19 because of its similarity and to the more common coronaviruses people are regularly exposed to.  Once recognized the immune system has the capability to attack it with T-killer cells and potentially create and secrete antibodies through macrophages and plasma cells.

Since March 2020 I have been curious to the reasoning behind asymptomatic cases and I am happy to find a potential answer to this long unanswered question.  Why do you think this research has taken almost three years to find the answer to.  Comparatively, the COVID-19 vaccine was made in around 8 months from March of 2020. Of course there was significantly more incentive and money invested into the development of the vaccine, however the two findings are years apart and the vaccine is seemingly much harder to research and develop.

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