The COVID-19 pandemic began over two and a half years ago, and SARS-CoV-2 mutations have come and gone. Pharmaceutical companies rushed to bring new vaccines onto the market.
A vaccine mainly aims to make neutralizing antibodies, but these play only a tiny part in our sophisticated natural immune system.
What Is Immunity?
Immunity is the ability of an organism to resist a particular infection or toxin.Humans have two levels of immunity, natural and acquired. We are born with natural (innate) immunity, which protects us from all types of pathogens, instead of specific ones. Acquired (adaptive) immunity is achieved by inoculation or getting infected by specific pathogens including viruses and germs.
5 Barriers of Human Immunity
Human immunity is similar to a multi-layered defense network and is composed of five barriers.- Physical barrier
- Epithelial cell barrier and interferon
When viruses invade epithelial cells, the latter automatically start their antiviral mechanism, mainly by producing interferons, which are important antiviral substances that can prevent the replication of viruses. In people with strong immunity, the mechanism of interferon secretion alone is sufficient to eliminate the viruses.
Interferons are produced by many immune cells (e.g. leukocytes, natural killer cells, natural killer T cells, and T cells). They don’t directly kill viruses. Instead, interferons “interfere” by instructing cells to produce many antiviral proteins and by enhancing the virus-killing mechanisms including intracellular pathways and activating innate immune cells.
The interferons produced in the early stage of a viral infection can delay the viruses’ replication and so delay their spreading to the entire body, thus buying time for the body to clear the viruses so that the chance of developing any illness is reduced.
Therefore, the body’s rapid ability to produce interferons ensures the success of the battle with a virus, like the first and second groups of the UK challenge trial.
- Innate immune cellular barrier
The third barrier is composed of innate immune cells, such as granulocytes, macrophages, dendritic cells, and natural killer cells.
There are three types of granulocytes, including neutrophils, eosinophils, and basophils.
Neutrophils are the most numerous of the three in the body and are produced very quickly. They are the first responders to infections and play a police-like role in innate immunity.
Eosinophils are very effective in fighting against parasites. Parasites are multicellular organisms that immune cells have difficulty swallowing. However, rather than swallowing parasites, eosinophils attack them by releasing chemicals that penetrate their cell membranes, so eosinophils play the role of a “disinfection worker.” In addition, eosinophils trigger inflammatory reactions in the body by releasing chemicals. They are common factors in allergic reactions, like “firefighters.”
Macrophages can engulf pathogens in large numbers. In comparison with neutrophils, macrophages have a higher capability to attack pathogens and are able to fight them for a longer period of time. In addition to macrophages, there is also a type of dendritic cells that can swallow pathogens.
After macrophages and dendritic cells swallow a pathogen, they will analyze it and pass the relevant information to the acquired immune system for further action against the “enemies.” They are the “communication bridge” or “messenger” between the innate and acquired immune systems. Although their functions are similar, they have their own strengths. Macrophages are stronger in phagocytosis, like the “riot police”; while dendritic cells are better at analyzing and transmitting information, like “signalers.”
Natural killer cells are also part of the advance troops, the vanguard and frontline of the natural immune system, mainly responsible for killing virus-infected cells and mutated cancer cells in the body.
The complementary system is like bullets that can destroy various pathogens, bacteria, viruses or abnormal cells. In addition, it also promotes the ability of phagocytes to engulf pathogens through its “conditioning effect.” In other words, if pathogens were mashed potatoes then the complementary system would be the gravy that adds flavor to them, and encourages phagocytes to consume more pathogens. Furthermore, the complementary system can promote other immune responses, such as inflammatory responses and the secretion of immune-modulating substances.
Generally speaking, there are two major types of T cells, including the helper T cells and the cytotoxic T cells. The former “help” other cells of the immune system, while the latter kill virally infected cells and tumors. T-cells have many receptors on their surfaces, and they can only bind to one shape of antigen. When a T-cell receptor fits with its viral antigen on an infected cell, the cytotoxic cell will releases cytotoxins to kill that cell. Cytotoxic cells can also kill foreign and cancer cells.
- B cell barrier
Compared with the first three lines of barriers, the reactions of T and B cells are relatively slow, and they are greatly affected by the specific viral genes and proteins. For instance, different COVID-19 variants require different T and B cells.
Therefore, it’s necessary to attack the cells directly infected by the virus according to the characteristics of the antigen.
A Sensible Way Forward
If we are purely relying on the vaccine to fight against SARS-CoV-2, COVID-19 vaccines need to be continuously updated to keep up with the different strains’ constant mutations.However the time to produce a new COVID vaccine is on average at least 8 months, which is far behind the speed at which the virus can mutate. A major new mutation has taken center stage every four or five months, as we have witnessed at least seven major strains (original strain, D614G, alpha, beta, delta, omicron BA1, BA4/5) during the past 32 months of the pandemic.
Luckily, people have the first four front layers of immunity, which can help us defend well against any virus, independent of the B cells or neutralizing antibodies.
According to Dr. Dong, a more sensible, rational, and effective way to avoid COVID-19 infection is to boost our natural innate and adaptive immunity so that it’s strong enough to protect us, just like the first two groups of subjects in the UK human experiment trial mentioned earlier.
We can do several things to improve our innate and acquired immunity. For instance, a diet rich in nutrition, a healthy work and rest schedule, and a stable and cheerful mood are all important. Furthermore, although it may sound inconceivable, honoring traditional values, as well as being more considerate for others can significantly improve the overall immunity of our cells.
Fuel Your Immune System
We need to pay attention to our intake of basic nutrients, and properly supplement vitamins and trace elements to maintain the normal structure and function of our first immune barrier.- Vitamin C: It can help with the differentiation and proliferation of T and B cells. A lack of vitamin C will lead to impaired immunity and higher susceptibility to infections.
- Vitamin D: It can reduce the incidence and severity of virus infection. A study has shown that adequate serum vitamin D level could protect us against severe COVID-19.
- Zinc: It helps activate white blood cells (i.e. immune cells) and is essential for wound healing. Zinc-rich foods in daily life include meat, spinach, and nuts.
- High intake of salt: It destroys beneficial gut bacteria, thus increasing chronic inflammation in the intestines, which is detrimental to the immune system’s antiviral efforts.
- High intake of sugar: It damages phagocytic cells (which swallow germs) and gut microbes. Consumption of sugar causes chronic inflammation, harms the interferon secretion in epithelial cells, and impedes the antiviral function of natural immune cells, T cells, and B cells.
Healthy Habits
In order to reduce the chance of COVID-19 infection, please pay attention to personal hygiene. For example, wash our hands and shower frequently, to remove the viruses if we have been exposed to them.On a similar note, we can also avoid drinking alcohol, as it damages epithelial cells, T cells, and B cells.
Exercising can also help us maintain a healthy body weight, as obesity triggers a chronic inflammatory state and counteracts the immune system’s antiviral abilities.
Mental Health and the Spirit
In an article published in the journal Brain, Behavior, Immunity in February 2021, several scholars from the United Kingdom and Taiwan suggested that in addition to the current pharmacological treatments for COVID-19, psychological support should also be implemented to improve people’s mental health and enhance their psychoneurological immunity to the pandemic.Inner Peace
According to a paper published in the journal Brain, Behavior, Immunity, depressed people have reduced lymphocyte responses, weakened T-cell immune responses to viruses, and reduced NK-cell activity, resulting in an overall trend of reduced antiviral immunity in the human body, making people vulnerable to viral and bacterial infections.In addition, depression also increases the production of inflammatory substances, such as pro-inflammatory cytokines and chemokines, leading to a chronic inflammatory state. Furthermore, negative emotions combined with stress can reduce the body’s immunity, adding to the vicious cycle that makes people more susceptible to the COVID-19 infections.
To break the vicious cycle, we may have to put down those painful secular goals so as to achieve better inner peace. Letting things naturally unfold is sometimes a release, and maintaining a cheerful mental status helps nourish our immunity.
How can one achieve inner peace? Staying honest is another way.
The higher the cortisol reactivity, the more likely that this stress hormone’s level is elevated in the body. Corticosteroids have a suppressive effect on immune cells, thus inhibiting the body’s ability to fight viruses. Therefore, in the midst of the pandemic, dishonest behavior can lead to a decrease in one’s own immunity.
Follow Traditional Values
Believe it or not, following traditional values can also improve the overall immunity of cells. An article published in 2021 in the journal Anxiety, Stress & Coping suggests that three strategies developed from evidence-based medical research can help people reduce anxiety, stress, and depression, and can help them get out of the pandemic faster.Compassion and Kindness
In a 2013 study published in the Proceedings of the National Academy of Sciences (PNAS), the immune system indicators of people with two different views of well-being were examined. One view is eudaimonic well-being, which is inclined to pursue human justice and noble goals, and hedonic well-being, which is more inclined to pursue personal sensory enjoyment. It was discovered that people of eudaimonic well-being have higher gene expression of interferons, higher antibody production ability, and significantly lower expression of inflammatory genes. The overall effect of their gene expression is more favorable for their body to fight against viruses, including SARS-CoV-2.
According to Dr. Dong, in the midst of the pandemic, there’s much more one can do to boost immunity than simply diet and lifestyle. It’s also of great benefit to advocate for the traditional values of honesty, kindness, and tolerance. Tapping into spirituality can also help enhance the body’s antiviral potential, and help people better cope with the lingering effects of the pandemic, and any other emerging viruses as well.
