COVID-19 Risk Factor: Men, Older Adults, Smokers More Prone to Getting Infected Due to Their Biology

A study led by Massachusetts General Hospital and the Broad Institute of Harvard and MIT reveals that men, older adults, and smokers are more prone to COVID-19 infection due to their biology.

The team analyzed hundreds of thousands of data on respiratory cell samples from the nasal passages and airways of participants. They discovered that men who are older adults and smoke traditional cigarettes have higher receptor cells that the virus uses to infect a person.

The team said that the findings do not provide a scientific explanation for biological pathways or why some people have a higher risk of being infected with the virus, and why some groups of people should be prioritized for vaccination, MailOnline reported.

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COVID-19: Men, Older Adults, and Smokers More Prone to Getting Infected Due To Their Biology

Why SARS-CoV-2 Prey On Certain Groups?

The reason why the novel coronavirus is targeting certain groups was unknown until recently with the MIT and Harvard study, entitled "Single-cell meta-analysis of SARS-CoV-2 entry genes across tissues and demographics."

Previous studies have revealed that SARS-CoV-2 is more likely to infect men and women, older adults than younger people, and smokers than non-smokers.

But the study, published in Nature Medicine, explains why the virus targets certain people. From a meta-analysis of data of over 1.3 million cells from the nasal airway, and lung tissue samples from 228 healthy people without COVID-19, the researchers found that these groups have high levels of angiotensin-converting enzyme 2 receptor (ACE2).

The SARS-CoV-2 virus uses ACE-2 to enter and infect human cells. Additionally, the team also looked at Transmembrane Serine Protease 2 (TMPRSS2) genes that cut open spike protein on the surface of the virus to help it enter cells.

MailOnline further reported that there was no statistical difference between TMPRSS2 genes and ACE-2 receptor cells between smokers and former smokers.

Associate professor Dr. Nicholas Banovich from the Integrated Cancer Genomics Division at the Translational Genomics Research Institute said that their findings reveal that age, smoking habits, and sex all played a significant role in the ability of SARS-CoV-2 to infect human cells.

He also said that this study adds to the growing information about comorbidities, such as hypertension and diabetes, that patients may have and make them at a higher risk for the infection. He pointed out that these people should be prioritized for vaccination.

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Not Sure Why Certain Groups Have More Of These Genes and Receptors

The MIT and Harvard meta-analysis builds on previous research that found goblet cells often have high levels of ACE2 receptors. Goblet cells secrete the main component of mucus in the nasal passage.

Although the study identifies the groups of people more prone to the infection, it does not however tell why these people have more of the genes and receptors that are necessary for the infection. For that, the team suggests further research is needed, Washington News Post reported.

The researchers wrote that their meta-analysis provides a detailed molecular and cellular map to help better understand SARS-CoV-2.