Maybe a reason why obesity is a factor in bad outcomes

If the article interpretation is correct, the fat cells the virus permeates may no longer be used for energy... which is really bad news for those of us who already have vascular problems, mobility problems, etc and thus difficulty losing weight. That puts a further onus on us to avoid getting COVID if even possible. Sigh...

Here is what was known in 2021.

Comorbidity Morbidity mortality

Despite the mechanisms for high morbidity and mortality induced by SARS-CoV-2 are currently unknown, based on available literature data in public databases, it is known that the risk of infection and mortality increases with advancing age and also seems to show a sexual dimorphism, male elderly subjects are at higher risk of infection, as well as death (1, 2). In addition, despite COVID-19 is a non-discriminatory disease, involving both healthy individuals and those with comorbidity conditions, it is well-documented that mortality further increases in presence of pre-existent pathologies, such as cardiovascular disease, hypertension, diabetes, obesity, chronic pulmonary disease, and cancer (12–14). Despite, the biological mechanisms behind these observations are still unclear, virus/host cell interaction, immunological differences, and sex-based hormonal differences are likely to be involved. https://www.frontiersin.org/articles/10.3389/fmed.2020.594495/full

Vitamin D is important for immune function, modulates the inflammatory response to infection, and regulates the renin-angiotensin system.

• Ecologic studies: Countries with lower average levels of 25(OH)D or lower solar ultraviolet-B radiation exposure have higher COVID-19 mortality.

• Demographic groups known to be at higher risk of vitamin D deficiency—Black individuals, the elderly, nursing-home residents, and those with obesity, vascular comorbidities, or chronic kidney disease—are also those at high risk of COVID-19 hospitalization and/or mortality. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3166406/

VIDEO reminding that there are receptors in immune cells for Vitamin D (as well as a multitude throughout the body) and that people of colour, people who are Obese and the elderly are all more likely to be vitamin D deficient. Lots of studies and charts to show the association. (Observational data is still limited as it has other relations to health) https://www.youtube.com/watch?v=ha2mLz-Xdpg

“If you really are very obese, fat is the biggest single organ in your body,” Dr. Kass said. The coronavirus “can infect that tissue and actually reside there,” he said. “Whether it hurts it, kills it or at best, it’s a place to amplify itself — it doesn’t matter. It becomes kind of a reservoir.” As the inflammatory response snowballs, cytokines trigger even more inflammation and the release of additional cytokines. “It’s like a perfect storm,” he said.

Inflammation is the body’s response to an invader, and sometimes it can be so vigorous that it is more harmful than the infection that triggered it. “The more fat mass, and in particular visceral fat mass, the worse your inflammatory response,” Dr. McLaughlin said, referring to the abdominal fat that surrounds internal organs.

Fat tissue is composed mostly of fat cells, or adipocytes. It also contains pre-adipocytes, which mature into fat cells, and a variety of immune cells, including a type called adipose tissue macrophages.

https://www.nytimes.com/2021/12/08/health/covid-fat-obesity.html

Epithelial tissue and COVID

COVID can harm organs and scars organ tissue and not just in lungs.

[ Epithelial tissue damage means a protector barrier for cells may be permanently scarred and damaged] As with everything else pertaining to health, Age, earlier viruses or cig smoking damage and many other factors determine healing from COVID. Epithelial repair mechanisms in the lung

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2886606/

Respiratory epithelial cell responses of the alveolar epithelium:

Respiratory epithelial cell responses to SARS-CoV-2 in COVID-19 of the alveolar epithelium:

Potential for structural and functional damage and severe illness https://thorax.bmj.com/content/77/2/203#block-system-main

Epithelial Inflammation

SARS-CoV-2 Causes Severe Epithelial Inflammation and Barrier Dysfunction. Apr 2021. https://journals.asm.org/doi/10.1128/JVI.00110-21