A Comprehensive Article
The aim of this article is to analyze what is happening with SARS-CoV-2 (the virus causing COVID-19 pandemic) from a medical perspective, construct a big-picture view of the situation, and provide actionable insights for individuals. The goal is for the reader to obtain a general understanding of what is known about the virus, providing context in which to file new information materializing daily.
It is written from the viewpoint of Andrei Volgin, MD PhD, who has worked in multiple healthcare research disciplines and specialized in immunology. See Andrei’s LinkedIn here.
This article does not constitute medical advice, nor does it constitute a doctor-patient relationship. If you are experiencing changes in health or have questions about your health, consult your doctor.
Your doctor’s orders supersede what is written here.
The SARS-CoV-2 pandemic is a dynamic, ever-changing situation. Many things remain uncertain until relevant research is completed. This analysis is based on the information currently available, and will change accordingly when new, applicable information is presented.
This article consists of 4 parts containing cited explanations, and a summary of action steps in conclusion:
I. Understanding Immunity: The Innate & Adaptive Immune Systems
II. Why is COVID-19 So Different from What We’ve Encountered Before?
III. The Infection Dynamic
IV. Minimizing COVID-19 Infection Chances & Infection Severity
V. Skip to Action Steps Summary
To understand how COVID-19 impacts the body, it is necessary to understand the dynamic of the human immune system.
The human body has effectively evolved 2 immune systems1:
Adaptive immune response (sterile)
The ancient, innate immune system evokes a nonsterile immune response, meaning as long as a small amount or weakened version of the pathogen (virus, bacteria) stays alive or intact in the body, the body is able to produce an adequate immune response enough to stave off infection in the event of exposure. This is how the BCG2 (Bacillus Calmette-Guérin, used primarily for tuberculosis) vaccine works; a weakened strain of the bacteria is injected, so that when the body is exposed to infectious tuberculosis (TB) bacteria from a foreign source, the body already has sufficient immune response to ensure no infection occurs with the infectious strain. If the weakened TB bacteria injected during vaccination dies completely, so does the body’s immunity to TB. The individual may be completely susceptible to TB as if vaccination never occurred. Furthermore, a study showed that the viability of the TB vaccine could be affected by heavy modern antibiotic use.3
The innate immune system is highly complex, and although the entire composition of the innate immune system is not exhaustively known, identified components include: barriers to infection (mucous membranes, epithelia of skin, gastrointestinal, respiratory, genitourinary tracts), antimicrobial peptides and proteins, humoral components and cellular components4 (such as natural killer cells).
The more modern, adaptive immune system evokes a sterile immune response which completely rids the body of the pathogen to remove infection. Once a person has been infected by (and survives) or vaccinated from these diseases, they should not have it again. This occurs with diseases such as polio, measles, rubella, Hib, pneumococcus, or meningococcus vaccines, their body rids itself of the pathogen completely, and the immunity for that pathogen stays for a long time or forever. The adaptive immune response is based on the creation of T memory and B memory cells post-infection or vaccination5 that activate to rid the body of infection immediately upon exposure.
COVID-19 actively attacks the adaptive immune response, not allowing T and B memory cells to form effectively. This is the reason why it is very difficult to create a vaccine for COVID-19. HIV acts similarly by attacking the adaptive immune system, making it practically impossible to create a vaccine for it. Since the AIDS crisis of the 1980’s, no vaccine has yet been created.6
An important factor with innate immune responses, such as with COVID-19, is that if the body rids itself of the infection completely, that individual may again be susceptible to infection by the same strain. Immunity resets to its initial state (effectively no immune response). In most cases, antibodies created during this time are usually weak7 and not sufficient to prevent re-infection.
Since COVID-19 attacks the adaptive immune system and immunocompetent memory cells are not effectively created, the body is heavily dependent on the innate immune system to fight infection.
The body’s first barrier to the virus is the innate immune system. If the innate immune system works well, giving the adaptive immune system a chance to produce effective antibodies for COVID-19, the individual is able to obtain immunity from becoming sick again. This occurs in a small percentage of an infected population. The immune subset of the population comprises the “herd immunity”8 that protects the larger population from pandemic growth.
Antibody tests for individual use can only prove that the individual became infected with and produced antibodies to COVID-19, but it does not guarantee that these antibodies will be effective in inactivating the virus. The presence of IgM antibodies shows that the individual is actively battling infection and the presence of IgG antibodies shows that the individual has overcome active infection.9 Antibody tests may be useful for scientists studying infection dynamic and response in a population, but they are not particularly useful for individual use other than this insight.10
Just as both the innate and adaptive immune systems have evolved to battle infection, viruses also constantly evolve to evade human immune system defenses. The COVID-19 virus has done the same.
The 3 factors that generally determine COVID-19 infection severity in an individual are:
For small viral load exposure with a strong innate immune system, the following options are most likely:
If an individual has a weakened innate immune system, the result is different.
If an individual is exposed to a very high viral load, they will likely become infected regardless of immune system strength.
This is partially the reason why we are seeing seemingly healthy front-line workers14 such as doctors, nurses, EMT and police15 infected and dying from COVID-19. The majority of immune systems cannot withstand repeated high viral load exposure from COVID-19 without experiencing significant effects. Front line workers are also more likely to come into contact with multiple virus strains,16,17 and thus possibly more aggressive strains, meaning their bodies must fight harder to stave off severe infection.
Once the body’s innate immune system becomes overwhelmed, like a dammed lake receiving too much rain, the system collapses and floods the body with too much to handle. It is crucial to ensure that viral load exposure remains minimal, so that the dam never breaks, and symptoms remain either nonexistent or low intensity.
So then, how do we prevent or minimize infection most effectively, on an individual scale?
There are 5 approaches that minimize COVID-19 infection risk and/or severity:
1. Eliminating or minimizing exposure to viral load
a. Complete isolation
b. Proper personal protective equipment (PPE) during times of exposure
Mask wear and other measures
c. Equipping the home correctly to prevent self-infection
2. Supporting the innate immune system by reinforcing gut microbiome & virome health
a. Intro to the gut microbiome and virome
b. How the microbiome and virome are interconnected
c. Developed vs. non developed country microbiome health
d. What to eat
3. Increasing expulsion of viral particles from the body
a. Light exercise outside the home
b. Drinking fluids
4. Recovery & rest (sleep)
1a. Complete isolation
The most effective way to prevent infection is complete isolation. This is recommended for individuals with immunocompromised states or other diseases that may raise risk for severe infection or complication. This includes individuals over the age of 65, individuals who are obese, who have asthma, chronic kidney disease being treated with dialysis, chronic lung disease, diabetes, hemoglobin disorders, liver disease, or with serious heart conditions.18
1b. Proper PPE during times of exposure
Proper PPE for frontline workers at work and for citizens during times of exposure (presence in public spaces such as grocery stores, pharmacies, etc.) is crucial for reducing chance of infection. The term “PPE” is used to refer to the collective protective measures an individual can take to reduce viral infection chances.
The virus can enter the human body19 through:
Any time an infected individual speaks, coughs, or sneezes, they expel infectious viral particles.21,22
Masks protect the breathing and digestive systems by reducing viral exposure.
Glasses/face shields protect the eyes by reducing viral exposure.
Gloves protect the skin of hands from high viral load exposure and subsequent contamination of mucous membranes (eyes, mouth), clothes, and skin by touch. Gloves also protect the skin from infection through microtears on hands and protect the skin of hands from losing integrity from overuse of sanitizers, including keeping the skin microbiome intact.
Proper PPE for Frontline Workers
Correct PPE use for frontline workers23 reduces viral load exposure to the point where a worker may become infected, but not severely enough to develop life-threatening symptoms. Unfortunately, most front-line workers either do not have access to proper PPE or proper PPE use training, which is just as vital as its availability. Front-line worker behavior is critical in determining the wellbeing of their fellow front-line workers and the community they serve.
It is crucial to avoid any public service if a worker is feeling sick, and it is extremely crucial that management recognizes and rewards this safe behavior.
Proper PPE Use for Citizens
Correct PPE use for citizens consists of wearing and disposing of PPE properly during times of possible exposure.
The goal is to minimize viral load exposure for the wearer and to minimize viral load expulsion from the wearer.
Wearing a medical or cloth mask to prevent viral particle exposure in the air, and to prevent spreading viral particles if you are infected.
A mask will not filter aerosolized viral particles, but it will filter viral particles that are attached to larger airborne particles, such as dust, pollutants, saliva from talking/sneezing/coughing, etc. This means you will likely be exposed to small and medium amounts of the virus in public, but very large doses, like those emanating from carriers,24–27 could be filtered if they are attached to larger particles. A significant portion of viral particles expelled from a carrier may be filterable by a mask if they are attached to larger particles, which the mask stops.28
Masks also reduce the area29 in which exhaled breath travels, so frequenting a location with a high mask wear rate30 poses less risk of encountering airborne viral particles.24 After a mask is worn, it must be carefully removed31 so that the inside or outside surfaces of the mask are not touched, and either thrown directly into the washing machine (cloth masks), or laid out in direct sun to disinfect for 3+ days32 if they must be reused (medical/other masks).
Infection can occur by improper mask disposal. If cloth masks are reused, they should be sealed in an airtight container when removed and washed in hot water and ironed afterward. Medical/other masks that are disposed should be placed in an airtight bag prior to disposal. If your mask becomes wet or moist, it is no longer effective.
It is smart to wear a mask, if you wear it correctly.33
Wearing gloves when you will be encountering a high-traffic touch area like a grocery store.
Once you put on gloves, you must act as if the virus is already on them. Do not touch34 your phone, face, mask, keys, wallet, purse or other belongings, unless you have a plan to disinfect them before they’re touched again by clean hands. Gloves protect you from coming into contact with viral particles during a specific, short task, and spreading them to other surfaces after the task is complete. Once you exit the grocery store and remove your gloves by rolling them inside-out,35 careful not to touch any external glove surface, place them in an airtight container and throw them away at home. Gloves do not provide immunity; they merely prevent spread during an acute period of time to complete a task.
Wear glasses/sunglasses or a face shield when you will be visiting a public location where a chance of infection is possible or high.
Viral particles attached to airborne larger particles may hit your glasses as opposed to your eyes. You can visualize it this way: you must run through a cloud of flour. If you’re wearing glasses, it’s likely the flour won’t hit your eyes directly as much. If you’re not, it will likely hit your eyes, or closely around them, increasing possibility of eye contact. Glasses also prevent microdroplets during speech24–27 from directly entering your eye.
Disinfect your glasses after exposure.
Sanitizing personal belongings you touch during exposure.
If you enter a grocery store and handle your keys, phone, or credit card during your visit, have a plan to sanitize them before you touch them with clean hands. You may do so with hand sanitizer, or a homemade isopropyl or ethyl alcohol mixture of 70% ethanol or isopropyl alcohol and 30% water.36
Washing your hands.
Wash your hands correctly37 before and after exposure to others, visiting public places, returning home, or handling packages or items that have been handled by others. Wash your hands before you eat. See the CDC’s guidelines for hand washing here.37
Reducing body surface area exposure when frequenting possible exposure areas.
If you have long hair, it is wise to tie it back or tie it up so that it is not wafting in exposed air.
Do not continue to wear the clothes you wore while possibly exposed outside at home. Wear covering clothes that you immediately remove upon returning home, and place them in an airtight bag that you wash separately from other clothing. Do not unnecessarily disturb the bag, and handle with care when loading into the washing machine. If you go out in shorts or short-sleeve shirt, you can take a shower with soap.
Keeping your distance during physical exposure.
Almost everyone is aware that it is wise to keep at least a 6 feet physical distance38 between you and others when possible. Keeping physical distance reduces the chances of encountering another individual’s viral load.
Cleaning/disinfecting items brought into the home from an external source to lessen viral load exposure.
Once you obtain groceries or other items, it is wise to disinfect the packaging,39 or remove packaging altogether. Wash40 fruits and vegetables thoroughly. If you receive food delivery/takeout, do not handle or eat from the original containers. Disinfect the containers, then transfer the food to clean dishes.
It’s best to handle possibly contaminated clothing and items with gloves.
If you receive cardboard packages, such as Amazon or UPS delivery, they should be relatively safe for complete handling after 1 day41 (perhaps less, if the package is left at the door outside of the home in outdoor conditions). The package may be brought inside and left to sit until the next day to open, or can be opened immediately if the packaging is discarded and hands sanitized afterward. The virus lives longer on plastic (up to 6 days41), so consider the surface of packages and length of time they’re left untouched prior to handling.
Don’t go overboard.
It is important to disinfect and clean appropriately, but it is important not to go overboard. Washing hands to the point of skin breaking poses a higher risk for infection. Over-washing could also negatively impact the protective skin microbiome,20,42,43 also increasing risk of infection. This is why we suggest glove use, as opposed to merely washing hands often; some individuals in constant exposure situations would have to wash hands very often, leading to negative effects on the skin, causing it to lose protective integrity.
PPE and immunity
Some individuals feel that wearing PPE reduces their exposure to viruses and bacteria significantly enough that their immune system becomes untrained to fight off infection. This is most likely untrue, as you will still be exposed to a multitude of microorganisms in your daily life in the time that you are not wearing PPE. This includes exposure to microorganisms during your time at home, while working, exercising, being outside, and through foods. You will still be exposed to small amounts of COVID-19 and other viral particles while wearing a mask in public areas, just fewer of them than if you did not wear a mask at all. PPE provides strategic protection during a specific task, and it will not change the entire dynamic of your immune system, unless you are wearing complete PPE 24/7 for prolonged periods of time, which is not recommended.
Some individuals also have expressed concerns regarding side-effects of mask wear, such as low blood oxygenation levels. If you have no underlying respiratory/health problems and wear the right masks correctly during periods of exposure, the effect of possible low blood oxygenation (if any) poses a much smaller risk than possible high viral load exposure for the limited time you are wearing a mask. As a personal example, Dr. Volgin used a mask during his research of sterile cultures for his entire research career, and has never had problems with oxygenation or brain function. However, if you have underlying health conditions that could impact your breathing44 with a mask, consult your doctor for further information.
Using proper PPE not only reduces your risk of infection, but it also reduces the risk of you spreading infection to others28 if you are an asymptomatic carrier, low symptom carrier, are in the incubation period, or tested positively but are breaking your doctor’s quarantine orders (highly unrecommended). While some individuals may believe they won’t become significantly sick or that they are immune, it is vital to know that others are not. Wearing proper PPE in public spaces or during physical interaction helps protect others who are at risk of infection and complications. Even if someone feels that they will not come into contact with high-risk populations, they may infect others who do.
Recent studies45–47 show that nearly half of patients are infected by people who are not noticeably symptomatic. Because they don’t feel sick themselves, people may not be aware of the risk they pose to others, especially since they may never become noticeably sick. For example, Patient 1 in Italy48 frequented several public establishments when he was asymptomatically infectious. He infected about 80 individuals in one night that then started the pandemic in Italy.
The most responsible action an individual may take is to consider the effects of their own actions on others, especially during a pandemic.
Use PPE properly to decrease your own infection risk. If you do not want to wear PPE for your own protection in shared areas, consider others.
1c. Equipping the home correctly to prevent self-infection
Since the COVID-19 virus first attacks surfaces protected by the innate immune system, like mucous membranes, it is possible that the virus can be prevented from further permeating the body by being stopped at this first immune barrier. However, it may be possible that an individual, by living in an enclosed space with little air circulation, can infect themselves further or re-infect themselves with their own virus if it is not cleared from the space and if that individual did not develop immunity. The virus is expelled through exhalation, and can accumulate in enclosed spaces, infecting or re-infecting the host that originally expelled the virus.
Some measures can be taken to prevent this:
If you or someone in your household is sick, see the CDC’s guidelines for protecting co-inhabitants here.52
Keeping the air fresh and circulating in your home may reduce self-infection risk. Ensure you take proper measures if someone in your household is sick.
To begin, it is necessary to understand what the microbiome and virome are, how they impact the individual human, and how they impact human populations.
The gut microbiome53 is a collection of microorganisms, mainly bacteria, that live in the human digestive tract, with the most impactful microorganisms residing in the large intestine. The gut microbiome is comprised of powerful diverse bacterial colonies that work together in a unified community to accomplish several important tasks:
It directly influences the immune system,54,55 endocrine system,56 digestive system57(p1) and nervous system.58 The microbiome also plays a role in a human’s development of various diseases,59 such as obesity, cardiovascular disease, food allergies and other autoimmune problems, depression, anxiety, cancer, and even Alzheimer’s. A human cannot be truly healthy without a healthy microbiome.
Although this organ exists within the human digestive system and acts like a cohesive organ in partnership with the human body, it is not directly part of the human body, and belongs to the biosphere.
The virobiome or virome is generally regarded as a subset of the microbiome, and includes the multiple viruses that live within the microbiome and body of a human.60 The gut microbiome exists in the digestive tract, but the virome exists within cells throughout the human body, including the digestive tract. Some viruses are integrated into human DNA in heterochromatin areas,61 and some viruses exist as separate particles in and around human cells.
The virome is a dynamic system, with viruses cutting themselves in and out of human DNA, infecting human cells and initiating infection processes. A released, infectious virus can integrate itself into the DNA of its host, like what occurs during herpes virus infection.62 It is unknown how many viruses exist within human cells, but the dynamic of the human virome depends on the influence of the host individual microbiome and on the host species collective virome. Researchers do not classify viruses as independently living organisms, but together with host cell interaction and their collective influence within ecosystems, they behave like an informational emergent network.63
Although this is a relatively new area of study, some researchers know that the virome is very closely linked to human health: virome diversity can influence rapid viral evolution, horizontal gene transfers, and intimate interactions with host DNA. The viruses that exist in the human body determine the body’s response to disease. These viruses also have the ability to influence the microbiome in a way that can “promote or prevent pathogen colonization.”64
The microbiome, which is closely tied to immune system health, and the virome, which also intimately influences immune response, must be considered. The gut microbiome must be supported and maintained, so that the individual’s virome has the chance to properly “prevent pathogen colonization.”
Frequent mass vaccination using vaccines made with modern molecular genetic techniques provide effective immune response for hosts, but carry informational genetic components that can disrupt the host virome and lead to destructive effects.
The virome’s dynamic is directly influenced by microbiome communication.
In order for the body to be able to effectively fight off viruses, it needs to have a strong and robust microbiome.
It is still difficult to determine what exactly constitutes a “healthy” microbiome, aside from diversity, but actionable insights can be suggested for diet and lifestyle.
Why is eating non-industrialized foods absolutely critical for microbiome and immune health?
Modern food technology has nearly completely removed native microorganisms from human food, and we no longer receive the beneficial microorganisms we require through our diets. Our bodies need hundreds, if not thousands, of various microorganism species for microbiome support that should be replenished with what we eat. As soon as modern growing, processing and storage technology destroyed friendly microorganisms, modern microbiomes started to become sick. Since a sick microbiome does not support human health, populations living in developed countries that use modern food technology have begun to experience a sharp rise in “lifestyle diseases” caused by worsening microbiomes. Obesity, cardiovascular disease, food allergies and autoimmune problems, depression, anxiety, and even Alzheimer’s disease and cancer, and now increased COVID-19 infection risk are directly connected to an unhealthy microbiome.
The industrialized food phenomenon, and thus microbiome health, is reflected in COVID-19 infection rates. It seems that countries with lower food industrialization infrastructures have healthier microbiomes, which interact favorably with the virome, and are able to stave off infection more effectively than their Westernized counterparts.
Interestingly, in January, the WHO director was greatly concerned by COVID-19 spreading in low-industrialized countries,65 but when this spread was not reported, “the disproportionately smaller number of cases reported from disadvantaged/low income countries remains puzzling.”65 Dr. Volgin postulates that the reason is partially due to the fact that lower industrialization of food production in these countries allows food to retain its healthy native bacteria and other factors, feeding the microbiome with the right microorganisms, and allowing the microbiomes and immune systems of populations in less developed countries to better fight COVID-19 infection.
Other interesting studies that investigated the strength of unindustrialized microbiomes studied the Hadza hunter-gatherers of Tanzania,66 Nicobarese tribal community,67 Savar Indian foraging tribe,68 all point to one similar conclusion: “The Western diet is basically wiping out species of bacteria from our intestines.”68
A study even states that Some of the “variations in microbiome structure have been attributed to differences in host genetics and innate/adaptive immunity,”69 directly tying the health of the microbiome to immunity.
Of course, there are many other factors that impact infection in Western nations like widespread “lifestyle diseases” including autoimmune disease, obesity and cancer, but many root causes of these diseases may be tied directly to microbiome health.59 Correlation does not equal causation, of course, but this relationship is interesting to note.
The modern individual gut microbiome in industrialized countries is becoming more and more “sick,” leading to a decline in innate immunity strength, increasing infection risk. Unfavorable microbiomes also stimulate lifestyle diseases, which increase infection risk.
What can you do to support your microbiome, favorably impact your virome, and support your innate immune system?
Innate-system boosting vaccines
The medical society is discussing the possibility of increasing innate immunity through vaccines, such as BCG or polio vaccines. Initial data is positive,73 but requires further investigation.74
Viral particles leave the body through exhalation and excretion, so a few suggestions can be made:
3a. Light exercise outside the home
“Moderate intensity exercise improves immune function and potentially reduces risk and severity of respiratory viral infection.”75 If you can do so safely and with enough distance between yourself and others, for example, in a large enough backyard, engage in light exercise. Spend about 15-30 minutes, 3-7 days a week at low to medium intensity, depending on your existing fitness level. The goal of this exercise is not to raise your fitness level, but to warm up the body, promote blood circulation and increase sweat production to help encourage cellular toxin and waste removal. Exercise also physically remove viral particles from the airway. This activity can include walking, gentle yoga, gentle calisthenics, gardening, or other low-impact forms of exercise.
Note that it is important avoid over-exercise, as “prolonged, intense exercise causes immunosuppression75.”
It is also important to exercise safely outside of the home, so the expelled viral particles do not enter your living or working area. If this is not possible, increase air exchange in the room you use to exercise by opening a window/door to promote a draft.
Researchers state that there is a “compelling link between physical activity and the body’s defense system,”76 naming a new area of study dubbed “exercise immunology.”
Shower after exercise is important to remove viral particles that may have accumulated on your skin through exhalation and bodily fluids.
3b. Drinking fluids
Keeping the body hydrated is critical for proper body function and for the expulsion of toxins from the body.77,78 Drink enough water to prevent feeling “thirsty,” since by that time, you are likely already somewhat dehydrated. Consume 2-3 liters of liquids a day. It is important that you do not over-hydrate, just as it is important to remain hydrated.
One of the most important factors in recovering from COVID-19 or preventing infection is proper rest, specifically sleep. Sleep is absolutely critical for immunity: “sleep affects various immune parameters, is associated with a reduced infection risk, and can improve infection outcome79” It is known that “sleep regulates immune functions”80 and furthermore, “sleep after vaccination boosts immunological memory.”81 Be careful not to chronically deprive yourself of sleep, as “sleep deprivation makes a living body susceptible to many infectious agents.”82
If you have the ability to, plan your schedule such that you prioritize sleep in order to receive an adequate amount. This should be 7-9 hours a night83 minimum, plus more if you are experiencing stress, exerting yourself physically, or feeling that you might be coming down with an illness (from 8 to 12 hours). Out of everything listed here, aside from proper protection from viral load, this is the most important factor for remaining safe and healthy during a pandemic.
Sleeping sufficiently is crucial. Not enough sleep may cause the innate immune system to not be able to fight off infection.
Recovery from physical exertion is also crucial. It is important not to over-train if you are an athlete, as excessive training results in negative returns past a certain point. Studies show a “J-graph” style of negative returns on the immune system: passing a certain training intensity increases risk of infection.76
Individuals infected with COVID-19 have reported weaker feeling muscles and fatigue.84,85 It is important to adjust exercise accordingly. Over-exercise is more dangerous than not exercising at all.
It is crucial to not harm yourself through negative thoughts, panic, stress and fear. Do not allow yourself to become fixated on negative ideas. Notice bad thoughts, and then let them pass. Figure out the tools that best help you manage worry and stress, and learn to use them.
Focus your attention on positive events and thoughts. Notice beautiful or happy occurrences in your environment more than you notice the negative. Spend more mindful energy on things that bring you joy.
Select activities for your free time that make you happy.
A healthy mindset helps your overall health.86,87
COVID-19 has already brought enough negativity into our lives, don’t help it by contributing excessive negative thoughts and emotions to the situation.
In summary, the following action steps should be followed for individuals who would like to minimize their risk of contracting COVID-19 and/or lower infection severity.
1. Minimize unnecessary exposure
2. Support the innate immune system by reinforcing gut microbiome & virome health
3. Increase expulsion of viral particles from the body
4. Prioritize sleep significantly
5. Strive to live with a healthy mindset
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1. Information NC for B, Pike USNL of M 8600 R, MD B, Usa 20894. The Innate and Adaptive Immune Systems. Institute for Quality and Efficiency in Health Care (IQWiG); 2016. Accessed May 26, 2020. https://www.ncbi.nlm.nih.gov/books/NBK279396/
2. Okafor CN, Rewane A, Momodu II. Bacillus Calmette Guerin (BCG). In: StatPearls. StatPearls Publishing; 2020. Accessed May 26, 2020. http://www.ncbi.nlm.nih.gov/books/NBK538185/
3. Durek C, Rüsch-Gerdes S, Jocham D, Böhle A. Sensitivity of BCG to modern antibiotics. Eur Urol. 2000;37 Suppl 1:21-25. doi:10.1159/000052378
4. Innate Immune System – an overview | ScienceDirect Topics. Accessed May 26, 2020. https://www.sciencedirect.com/topics/immunology-and-microbiology/innate-immune-system
5. Chaplin DD. Overview of the Immune Response. J Allergy Clin Immunol. 2010;125(2 Suppl 2):S3-23. doi:10.1016/j.jaci.2009.12.980
6. February 21 CSH govDate last updated:, 2020. HIV Vaccines. HIV.gov. Published February 21, 2020. Accessed May 26, 2020. https://www.hiv.gov/hiv-basics/hiv-prevention/potential-future-options/hiv-vaccines
7. Tay MZ, Poh CM, Rénia L, MacAry PA, Ng LFP. The trinity of COVID-19: immunity, inflammation and intervention. Nat Rev Immunol. Published online April 28, 2020:1-12. doi:10.1038/s41577-020-0311-8
8. Randolph HE, Barreiro LB. Herd Immunity: Understanding COVID-19. Immunity. 2020;52(5):737-741. doi:10.1016/j.immuni.2020.04.012
9. Hou H, Wang T, Zhang B, et al. Detection of IgM and IgG antibodies in patients with coronavirus disease 2019. Clin Transl Immunology. 2020;9(5). doi:10.1002/cti2.1136
10. CDC. Information for Laboratories about Coronavirus (COVID-19). Centers for Disease Control and Prevention. Published February 11, 2020. Accessed May 26, 2020. https://www.cdc.gov/coronavirus/2019-ncov/lab/resources/antibody-tests-guidelines.html
11. Lauer SA, Grantz KH, Bi Q, et al. The Incubation Period of Coronavirus Disease 2019 (COVID-19) From Publicly Reported Confirmed Cases: Estimation and Application. Ann Intern Med. Published online March 10, 2020. doi:10.7326/M20-0504
12. Ghebrehewet S, MacPherson P, Ho A. Influenza. BMJ. 2016;355. doi:10.1136/bmj.i6258
13. Nile SH, Nile A, Qiu J, Li L, Jia X, Kai G. COVID-19: Pathogenesis, cytokine storm and therapeutic potential of interferons. Cytokine Growth Factor Rev. Published online May 7, 2020. doi:10.1016/j.cytogfr.2020.05.002
14. In Memoriam: Healthcare Workers Who Have Died of COVID-19. Medscape. Accessed May 26, 2020. http://www.medscape.com/viewarticle/927976
15. Feuer W. More than 1,000 New York City police officers have the coronavirus as 911 calls hit records. CNBC. Published April 1, 2020. Accessed April 23, 2020. https://www.cnbc.com/2020/04/01/more-than-1000-new-york-city-police-officers-are-infected-with-coronavirus.html
16. Holland LA, Kaelin EA, Maqsood R, et al. An 81 nucleotide deletion in SARS-CoV-2 ORF7a identified from sentinel surveillance in Arizona (Jan-Mar 2020). Journal of Virology. Published online May 1, 2020. doi:10.1128/JVI.00711-20
17. Spike mutation pipeline reveals the emergence of a more transmissible form of SARS-CoV-2 | bioRxiv. Accessed May 26, 2020. https://www.biorxiv.org/content/10.1101/2020.04.29.069054v2
18. CDC. Coronavirus Disease 2019 (COVID-19). Centers for Disease Control and Prevention. Published February 11, 2020. Accessed May 26, 2020. https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/groups-at-higher-risk.html
19. Drexler M, Medicine (US) I of. How Infection Works. National Academies Press (US); 2010. Accessed May 26, 2020. https://www.ncbi.nlm.nih.gov/books/NBK209710/
20. Handfield C, Kwock J, MacLeod AS. Innate Antiviral Immunity in the Skin. Trends Immunol. 2018;39(4):328-340. doi:10.1016/j.it.2018.02.003
21. Yan J, Grantham M, Pantelic J, et al. Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community. Proc Natl Acad Sci U S A. 2018;115(5):1081-1086. doi:10.1073/pnas.1716561115
22. Stelzer-Braid S, Oliver BG, Blazey AJ, et al. Exhalation of respiratory viruses by breathing, coughing, and talking. J Med Virol. 2009;81(9):1674-1679. doi:10.1002/jmv.21556
23. Douedi S, Douedi H. Precautions, Bloodborne, Contact, and Droplet. In: StatPearls. StatPearls Publishing; 2020. Accessed May 26, 2020. http://www.ncbi.nlm.nih.gov/books/NBK551555/
24. Anfinrud P, Stadnytskyi V, Bax CE, Bax A. Visualizing Speech-Generated Oral Fluid Droplets with Laser Light Scattering. New England Journal of Medicine. 2020;382(21):2061-2063. doi:10.1056/NEJMc2007800
25. Xie X, Li Y, Chwang ATY, Ho PL, Seto WH. How far droplets can move in indoor environments–revisiting the Wells evaporation-falling curve. Indoor Air. 2007;17(3):211-225. doi:10.1111/j.1600-0668.2007.00469.x
26. Atkinson J, Chartier Y, Pessoa-Silva CL, Jensen P, Li Y, Seto W-H. Respiratory Droplets. World Health Organization; 2009. Accessed May 27, 2020. https://www.ncbi.nlm.nih.gov/books/NBK143281/
27. Xie X, Li Y, Sun H, Liu L. Exhaled droplets due to talking and coughing. J R Soc Interface. 2009;6(Suppl 6):S703-S714. doi:10.1098/rsif.2009.0388.focus
28. Li Y, Guo YP, Wong KCT, Chung WYJ, Gohel MDI, Leung HMP. Transmission of communicable respiratory infections and facemasks. J Multidiscip Healthc. 2008;1:17-27. doi:10.2147/jmdh.s3019
29. Lai ACK, Poon CKM, Cheung ACT. Effectiveness of facemasks to reduce exposure hazards for airborne infections among general populations. J R Soc Interface. 2012;9(70):938-948. doi:10.1098/rsif.2011.0537
30. van der Sande M, Teunis P, Sabel R. Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population. PLoS One. 2008;3(7). doi:10.1371/journal.pone.0002618
31. How to Put on and Remove a Face Mask. Disease Prevention and Control, San Francisco Department of Public Health. Accessed May 27, 2020. https://www.sfcdcp.org/communicable-disease/healthy-habits/how-to-put-on-and-remove-a-face-mask/
32. Szeto W, Yam WC, Huang H, Leung DYC. The efficacy of vacuum-ultraviolet light disinfection of some common environmental pathogens. BMC Infect Dis. 2020;20(1):127. doi:10.1186/s12879-020-4847-9
33. Feng S, Shen C, Xia N, Song W, Fan M, Cowling BJ. Rational use of face masks in the COVID-19 pandemic. Lancet Respir Med. 2020;8(5):434-436. doi:10.1016/S2213-2600(20)30134-X
34. Cross Contamination and Gloves – YouTube. Accessed May 27, 2020. https://www.youtube.com/watch?v=EuUA05Y-ixY
35. How to Remove Gloves. :1.
36. Information NC for B, Pike USNL of M 8600 R, MD B, Usa 20894. Use of Disinfectants: Alcohol and Bleach. World Health Organization; 2014. Accessed May 27, 2020. https://www.ncbi.nlm.nih.gov/books/NBK214356/
37. When and How to Wash Your Hands | Handwashing | CDC. Published April 23, 2020. Accessed May 26, 2020. https://www.cdc.gov/handwashing/when-how-handwashing.html
38. CDC. Coronavirus Disease 2019 (COVID-19). Centers for Disease Control and Prevention. Published February 11, 2020. Accessed May 27, 2020. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/social-distancing.html
39. Grocery Shopping Tips in COVID-19 Revised (March 31, 2020) Www.DrJeffVW.Com. Accessed May 26, 2020. https://www.youtube.com/watch?v=zmoBI5m2_uw&list=TLPQMTkwNTIwMjCUvD6vC6j3Zg&index=2
40. Kilonzo-Nthenge A, Chen F-C, Godwin SL. Efficacy of home washing methods in controlling surface microbial contamination on fresh produce. J Food Prot. 2006;69(2):330-334. doi:10.4315/0362-028x-69.2.330
41. Suman R, Javaid M, Haleem A, Vaishya R, Bahl S, Nandan D. Sustainability of Coronavirus on different surfaces. J Clin Exp Hepatol. Published online May 6, 2020. doi:10.1016/j.jceh.2020.04.020
42. Chen YE, Fischbach MA, Belkaid Y. Skin microbiota–host interactions. Nature. 2018;553(7689):427-436. doi:10.1038/nature25177
43. Prescott SL, Larcombe D-L, Logan AC, et al. The skin microbiome: impact of modern environments on skin ecology, barrier integrity, and systemic immune programming. World Allergy Organ J. 2017;10(1). doi:10.1186/s40413-017-0160-5
44. Kao T-W, Huang K-C, Huang Y-L, Tsai T-J, Hsieh B-S, Wu M-S. The physiological impact of wearing an N95 mask during hemodialysis as a precaution against SARS in patients with end-stage renal disease. J Formos Med Assoc. 2004;103(8):624-628.
45. He X, Lau EHY, Wu P, et al. Temporal dynamics in viral shedding and transmissibility of COVID-19. Nature Medicine. 2020;26(5):672-675. doi:10.1038/s41591-020-0869-5
46. Liu Y, Centre for Mathematical Modelling of Infectious Diseases nCoV Working Group, Funk S, Flasche S. The contribution of pre-symptomatic infection to the transmission dynamics of COVID-2019. Wellcome Open Res. 2020;5:58. doi:10.12688/wellcomeopenres.15788.1
47. Ganyani T, Kremer C, Chen D, et al. Estimating the generation interval for COVID-19 based on symptom onset data. medRxiv. Published online March 8, 2020:2020.03.05.20031815. doi:10.1101/2020.03.05.20031815
48. De Giorgio A. COVID-19 is not just a flu. Learn from Italy and act now. Travel Med Infect Dis. Published online April 6, 2020. doi:10.1016/j.tmaid.2020.101655
49. Ghaus MS. Air-conditioning for infection control. Indian J Anaesth. 2011;55(3):322. doi:10.4103/0019-5049.82674
50. Hagbom M, Nordgren J, Nybom R, Hedlund K-O, Wigzell H, Svensson L. Ionizing air affects influenza virus infectivity and prevents airborne-transmission. Sci Rep. 2015;5. doi:10.1038/srep11431
51. Alonso C, Raynor PC, Davies PR, Morrison RB, Torremorell M. Evaluation of an electrostatic particle ionization technology for decreasing airborne pathogens in pigs. Aerobiologia (Bologna). 2016;32(3):405-419. doi:10.1007/s10453-015-9413-3
52. What to Do If You Are Sick | CDC. Accessed May 26, 2020. https://www.cdc.gov/coronavirus/2019-ncov/if-you-are-sick/steps-when-sick.html
53. Human Gut Microbiome – Volgin. Accessed May 26, 2020. https://myvolgin.com/science/human-gut-microbiome/
54. Wu H-J, Wu E. The role of gut microbiota in immune homeostasis and autoimmunity. Gut Microbes. 2012;3(1):4-14. doi:10.4161/gmic.19320
55. Role of the Microbiota in Immunity and inflammation. Accessed May 26, 2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4056765/
56. Sudo N. Microbiome, HPA axis and production of endocrine hormones in the gut. Adv Exp Med Biol. 2014;817:177-194. doi:10.1007/978-1-4939-0897-4_8
57. Bull MJ, Plummer NT. Part 1: The Human Gut Microbiome in Health and Disease. Integr Med (Encinitas). 2014;13(6):17-22.
58. Carabotti M, Scirocco A, Maselli MA, Severi C. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Ann Gastroenterol. 2015;28(2):203-209.
59. Lazar V, Ditu L-M, Pircalabioru GG, et al. Aspects of Gut Microbiota and Immune System Interactions in Infectious Diseases, Immunopathology, and Cancer. Front Immunol. 2018;9. doi:10.3389/fimmu.2018.01830
60. Cadwell K. The virome in host health and disease. Immunity. 2015;42(5):805-813. doi:10.1016/j.immuni.2015.05.003
61. Lieberman PM. Chromatin Organization and Virus Gene Expression. J Cell Physiol. 2008;216(2):295-302. doi:10.1002/jcp.21421
62. Weller SK, Coen DM. Herpes Simplex Viruses: Mechanisms of DNA Replication. Cold Spring Harb Perspect Biol. 2012;4(9). doi:10.1101/cshperspect.a013011
63. Emergent Behavior – an overview | ScienceDirect Topics. Accessed May 26, 2020. https://www.sciencedirect.com/topics/computer-science/emergent-behavior
64. Abeles SR, Pride DT. Molecular bases and role of viruses in the human microbiome. J Mol Biol. 2014;426(23):3892-3906. doi:10.1016/j.jmb.2014.07.002
65. Gursel M, Gursel I. Is Global BCG Vaccination Coverage Relevant To The Progression Of SARS-CoV-2 Pandemic? Med Hypotheses. Published online April 6, 2020. doi:10.1016/j.mehy.2020.109707
66. Schnorr SL, Candela M, Rampelli S, et al. Gut microbiome of the Hadza hunter-gatherers. Nat Commun. 2014;5. doi:10.1038/ncomms4654
67. Anwesh M, Kumar KV, Nagarajan M, Chander MP, Kartick C, Paluru V. Elucidating the richness of bacterial groups in the gut of Nicobarese tribal community – Perspective on their lifestyle transition. Anaerobe. 2016;39:68-76. doi:10.1016/j.anaerobe.2016.03.002
68. Ganguli S, Pal S, Das K, Banerjee R, Bagchi SS. Gut microbial dataset of a foraging tribe from rural West Bengal – insights into unadulterated and transitional microbial abundance. Data Brief. 2019;25:103963. doi:10.1016/j.dib.2019.103963
69. Gupta VK, Paul S, Dutta C. Geography, Ethnicity or Subsistence-Specific Variations in Human Microbiome Composition and Diversity. Front Microbiol. 2017;8:1162. doi:10.3389/fmicb.2017.01162
70. Langdon A, Crook N, Dantas G. The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation. Genome Med. 2016;8. doi:10.1186/s13073-016-0294-z
71. Francino MP. Antibiotics and the Human Gut Microbiome: Dysbioses and Accumulation of Resistances. Front Microbiol. 2016;6. doi:10.3389/fmicb.2015.01543
72. Bhalodi AA, van Engelen TSR, Virk HS, Wiersinga WJ. Impact of antimicrobial therapy on the gut microbiome. J Antimicrob Chemother. 2019;74(Suppl 1):i6-i15. doi:10.1093/jac/dky530
73. Miyasaka M. Is BCG vaccination causally related to reduced COVID-19 mortality? EMBO Mol Med. Published online 07 2020. doi:10.15252/emmm.202012661
74. Lawton G. Trials of BCG vaccine will test for covid-19 protection. New Sci. 2020;246(3280):9. doi:10.1016/S0262-4079(20)30836-8
75. Martin SA, Pence BD, Woods JA. Exercise and Respiratory Tract Viral Infections. Exerc Sport Sci Rev. 2009;37(4):157-164. doi:10.1097/JES.0b013e3181b7b57b
76. Nieman DC, Wentz LM. The compelling link between physical activity and the body’s defense system. J Sport Health Sci. 2019;8(3):201-217. doi:10.1016/j.jshs.2018.09.009
77. Armstrong LE, Johnson EC. Water Intake, Water Balance, and the Elusive Daily Water Requirement. Nutrients. 2018;10(12). doi:10.3390/nu10121928
78. Popkin BM, D’Anci KE, Rosenberg IH. Water, Hydration and Health. Nutr Rev. 2010;68(8):439-458. doi:10.1111/j.1753-4887.2010.00304.x
79. Besedovsky L, Lange T, Haack M. The Sleep-Immune Crosstalk in Health and Disease. Physiol Rev. 2019;99(3):1325-1380. doi:10.1152/physrev.00010.2018
80. Majde JA, Krueger JM. Links between the innate immune system and sleep. J Allergy Clin Immunol. 2005;116(6):1188-1198. doi:10.1016/j.jaci.2005.08.005
81. Lange T, Dimitrov S, Bollinger T, Diekelmann S, Born J. Sleep after vaccination boosts immunological memory. J Immunol. 2011;187(1):283-290. doi:10.4049/jimmunol.1100015
82. Asif N, Iqbal R, Nazir CF. Human immune system during sleep. Am J Clin Exp Immunol. 2017;6(6):92-96.
83. Chaput J-P, Dutil C, Sampasa-Kanyinga H. Sleeping hours: what is the ideal number and how does age impact this? Nat Sci Sleep. 2018;10:421-430. doi:10.2147/NSS.S163071
84. Singhal T. A Review of Coronavirus Disease-2019 (COVID-19). Indian J Pediatr. 2020;87(4):281-286. doi:10.1007/s12098-020-03263-6
85. Publishing HH. COVID-19 basics. Harvard Health. Accessed May 27, 2020. https://www.health.harvard.edu/diseases-and-conditions/covid-19-basics
86. Lamers SMA, Bolier L, Westerhof GJ, Smit F, Bohlmeijer ET. The impact of emotional well-being on long-term recovery and survival in physical illness: a meta-analysis. J Behav Med. 2012;35(5):538-547. doi:10.1007/s10865-011-9379-8
87. Lawrence EM, Rogers RG, Wadsworth T. Happiness and Longevity in the United States. Soc Sci Med. 2015;145:115-119. doi:10.1016/j.socscimed.2015.09.02
88. Rothan HA, Byrareddy SN. The epidemiology and pathogenesis of coronavirus disease (COVID-19) outbreak. J Autoimmun. 2020;109:102433. doi:10.1016/j.jaut.2020.102433
89. Liu B, Li M, Zhou Z, Guan X, Xiang Y. Can we use interleukin-6 (IL-6) blockade for coronavirus disease 2019 (COVID-19)-induced cytokine release syndrome (CRS)? J Autoimmun. Published online April 10, 2020. doi:10.1016/j.jaut.2020.102452