To slow the spread, focus on fresh air As evidence has accumulated over the course of the COVID-19 pandemic, scientific understanding about the virus has changed: the majority of transmissions occur as a result of infected people spewing large droplets and small particles called aerosols when they cough, talk or breathe. Surface transmission, although possible, is not thought to be a significant risk.  “Excessive attention on making surfaces pristine takes up limited time and resources that would be better spent on ventilation or the decontamination of the air that people breathe,” says engineer Linsey Marr, who studies airborne disease transmission. Nature | 11 min read

HEPA air filters are a very useful layer of protection in enclosed areas. Consumer reports has reviewed HEPA filters and rated several aspects. Alternatively you can build your own air filter with simple components as described here with 4 MERV 13 filters, duct tape, cardboard, and a simple box fan.

Since originally posting this page more information about the transmission of COVID 19 has become available. While spread through fomites (touching surfaces, clothing etc.) is theoretically one mechanism of spread it is unlikely that this represents a significant component. Here is an update from John’s Hopkins.

An editorial published in Nature discusses the need to shift focus away from surface decontamination as a mechanism to reduce SARS-CoV-2 transmission risk. Multiple studies have found that transmission of SARS-CoV-2 via contaminated surfaces, or fomites, is relatively rare compared to respiratory transmission via droplets or aerosols. Despite the evidence supporting respiratory exposure as the overwhelming driver of community transmission, numerous public health entities, including the WHO and US CDC, continue to emphasize the importance of surface decontamination, which can cause confusion among the public regarding transmission risk and appropriate protective measures. Notably, surface decontamination efforts, while highly visible and easy to recognize, are costly and likely not effective means of reducing transmission risk. The editorial calls for increased focus on improving ventilation and air filtration capacity to reduce respiratory exposure. Additionally, proper physical distancing and face mask use remain key tools in mitigating exposure and transmission risk for individuals.

The key to reducing the risk of symptomatic infection, especially moderate to severe illness and death appears to be vaccination. Beyond vaccination general health measures such as regular exercise (resistance training twice weekly for 20-30 minutes and aerobic  exercise 5-6 times per week), good sleep habits, stress reduction practices such as yoga, mediation, prayer and time walking in a green space all improve immune function.

Most important is to achieve and maintain metabolic health. Obesity associated insulin and leptin resistance is the most significant modifiable risk factor for severe disease and death. SARS CoV-2, like many other viruses, interferes with the production and signaling of interferon 1, an essential component of the innate immune system, which is the early response component of our immune system. Obesity, insulin and leptin resistance (causes:  sugar and refined carbohydrate intake, consumption of highly processed “vegetable oils”, lack of adequate muscle mass called sarcopenia, sedentary lifestyle, high stress levels, lack of social connection and purpose) also negatively affect our ability to generate interferon 1 and impair interferon signaling to various immune cells. The result is a profound increase risk for individuals who are obese, insulin and leptin resistant. These individuals suffer a double hit to the early immune response. First caused by the virus itself, second caused by underlying immuno-suppression associated with metabolic dysfunction.

Here is an image that depicts the immune evasion associated with SARS CoV-2’s ability to impair the innate immune response.

In the graphic above SARS CoV-2 virus interferes with interferon (IFN) production and signaling. This is compared to Virus X which does not. This impairment of the initial immune response results in a cascade of events in which the immune response is TOO LITTLE, TOO LATE, and then TOO MUCH (causing a cytokine storm and severe illness.)

The following graphic illustrates how immune suppression caused by SARS CoV2 and the deleterious effects of obesity/insulin-leptin resistance can affect outcome.

As a result, attention to the essential components of health remains the single most important thing you can do to reduce risk by supporting your immune system. In the following graphic the components of a healthy lifestyle circle the word HEALTH. Outside the circle are many factors that are deleterious to health in general and our immune system in particular.

There is a clear relationship between vaccination rates and hospitalizations as depicted here:

Early in the pandemic 50-60% of viral transmission appeared to be from asymptomatic individuals. This is likely true for the most recent variants. So wearing a mask, social distancing, and avoiding unventilated crowded indoor spaces remains extremely important as the more easily transmitted variants emerge and dominate. 

The Delta variant was 2.5 to 3 times more transmittable compared to the alpha variant. Now Omicron 4 and 5 variants are even more irascible. The rapid mutation rate of this virus is unique and has contributed to it’s widespread effects. The science keeps changing as new variants emerge.

DOUBLE MASKING IS MORE EFFECTIVE THAN SINGLE MASKS.

TRIPLE LAYER MASKS OF TIGHTLY WOVEN FABRIC IS MORE EFFECTIVE THAN SINGLE OR DOUBLE LAYERS.

N95 MASKS ARE MOST EFFECTIVE BUT THEY MUST FIT THE FACE WITH A TIGHT, SNUG FIT. 

TO IMPROVE THE BARRIER FUNCTION OF MASKS WEAR A SNUG FABRIC MASK OVER A SURGICAL MASK OR OVER AN N-95. THIS WILL PROTECT BOTH THE WEARER AND THOSE AROUND THE WEARER.

Doctors and nurses in hospitals and clinics often wear a surgical mask over an N-95. 

Face shields do not protect you or those around you from infection. Face shields and goggles likely decrease the risk of infection transmitted from aerosols that hit your eyes but do nothing for the most important mechanism of spread, breathing in aerosols or droplets into your nose. Aerosols will just spread around a face shield into your nose. 

Think about smelling the pleasant odors of food cooking in a kitchen. Face shields will not block those aerosolized food vapors from entering your nose, but tightly fitting masks will do it to some degree.

I have given 4 lectures on Acute and Long Covid 19, risk and mitigation strategies, nutritional immunology. One was recorded and can be viewed here.

In the context of the COVID 19 pandemic I will close with the usual summary.

1. Avoid alcohol consumption (alcohol wreaks havoc with your immunity)
2. Get plenty of sleep (without adequate sleep your immune system does not work well )
3. Follow good sleep habits
4. Exercise, especially out of doors in a green space, supports the immune system
5. Get some sunshine and make sure you have adequate Vitamin D levels. Supplement with Vitamin D3 to get your levels above 30 ng/ml, >40ng/ml arguably better.
6. Eat an anti-inflammatory diet rich in micronutrients.
7. Practice stress reduction like meditation and yoga which improves the immune system
8. Eliminate sugar-added foods and beverages from your diet. These increase inflammation, cause metabolic dysfunction, and suppress immunity.
9. Eliminate refined-inflammatory “vegetable oils” from your diet, instead eat healthy fat.
10. Clean up your home environment and minimize your family’s exposure to environmental toxins by following recommendations at EWG.org with regards to household products, personal care products, and organic foods. (https://www.ewg.org/)
11. Drink water filtered through a high quality system that eliminates most environmental toxins. (Such as a Berkey or reverse osmosis filter)
12. HEPA filters or the home-made version (Corsi-Rosenthal box) used in your home or workplace can reduce circulating viral load by 80%. This works for any respiratory virus transmitted by aerosol and this winter we have the triple threat of RSV, Influenza, and SARS-CoV-2. It also decreases indoor air pollution.
13. If you are eligible for vaccination, consider protecting yourself and your neighbor with a few jabs. Age > 50 and/or risk factors (Diabetes, pre-diabetes, insulin resistance, hypertension, obesity, heart disease, COPD, asthma, cancer treatment, immune suppression) suggests benefit from a booster. Risk for complications of boosters in adolescents, especially males, without risk factors, may equal benefit. Previous infection with Covid can be considered as protective as a booster. Discuss risk vs benefits with your doctor.

THIS WEBSITE PROVIDES INFORMATION FOR EDUCATIONAL PURPOSES ONLY. CONSULT YOUR HEALTH CARE PROVIDER FOR MEDICAL ADVICE.

Eat clean, drink filtered water, love, laugh, exercise outdoors in a greenspace, get some morning sunlight, block the blue light before bed, engage in meaningful work, find a sense of purpose, spend time with those you love, AND sleep well tonight.

Doctor Bob