COVID-19 Q&A #2 - Antibody-Dependent Enhancement, Cross-Immunity, Immunity Duration & More

Moderate exercise of one hour per day for five days a week has been shown to improve the immune system, but intense exercise for two hours or more has been shown to increase the risk of illness.

In the United States, 60% of the population has inadequate intake of vitamin E, 45% has inadequate intake of magnesium, 34% has inadequate intake of vitamin A, 25% has inadequate intake of vitamin C, and 8% has an adequate zinc. Omega-3 fatty acid intake is also very low, and 70% of the US population has insufficient vitamin D levels.

Approximately 70% of the US has vitamin D insufficiency while a further 28% has a low enough level to be called deficient. According to 'The Endocrine Society,' blood levels of 25-hydroxy vitamin D below 20 ng/mL is considered deficient and less than 30 ng/mL is considered insufficient.

Partial sleep deprivation can affect immunity. For example, humans immunized against infection with the influenza A virus during a period of partial sleep deprivation had virus-specific antibody titers less than half of those of non sleep-deprived individuals at ten days after immunization.

There are several studies that demonstrate that extreme endurance exercise does not benefit the immune system and can increase the chances of getting respiratory illness.

People that consume alcohol or are vegetarian may require more zinc. Alcohol increases zinc excretion by 50%, and vegetarians get their zinc from plant sources, which has zinc bound to phytate—this lowers its bioavailability.

A meta-analysis of three trials found that supplementation with zinc acetate lozenges—around 80 to 90 milligrams a day—resulted in a three-fold faster recovery rate from the common cold compared to a placebo.

With respect to COVID-19, data suggests that men and women are equally likely to get the disease, but men are more likely to die from it. Of 168 Wuhan patients who died from SARS-CoV-2, 75% of them were male.

Chronic sleep deprivation can affect immune cell numbers. For example, insomnia has been shown to be associated with significant decreases in the numbers of CD3-positive, CD4-positive, and CD8-positive T cells.

A meta-analysis of 25 randomized control trials found that vitamin D supplementation can decrease respiratory tract infections by more than 50% in people with vitamin D deficiency and by 10% in people that were already vitamin D sufficient.

Studies have shown that early exposure to microorganisms in the dirt—particularly before the first year of life—has been shown to significantly lower the risk of allergies, wheezing, and asthma in children.

The RDA for zinc is 11 mg per day for adult males and 9 mg per day for females. Approximately 8% of the US population has inadequate zinc intake, and up to 45% of people 60 and older have inadequate zinc intake.

Many studies have found that short-chain fatty acids derived from the gut microbiome promote the expansion of T regulatory cells. Reduced T regulatory cell numbers have been found in severe COVID-19 patients, and T regulatory cells have been shown to help resolve acute respiratory distressed syndrome. So, reduced T regulatory cell numbers might lead to worse lung pathology.

A randomized controlled trial in about 600 elderly individuals given a multivitamin that contained zinc for one year found those individuals with the highest zinc levels after supplementation were almost 50% less likely to get pneumonia.

Those with decreased ACE2 levels are also those who have been seen to have more severe COVID-19 cases—this includes people with chronic diseases, elderly, and males. It's been hypothesized that since ACE inhibitors and ARBs (angiotensin II receptor blockers) increase ACE2, they may reduce the risk of severe disease in these populations that are at risk.

One study found that even though patients tested positive for coronavirus up to two weeks after symptoms stopped, they no longer transmitted the virus to close contacts.