Why Your Natural Immunity Against COVID Is so Durable and How to Boost It

Why Your Natural Immunity Against COVID Is so Durable and How to Boost It
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Yuhong Dong
By Yuhong Dong, M.D., Ph.D. and Health 1+1, M.D., Ph.D.
9/3/2022
Updated:
3/10/2023
With some countries rolling out their 5th booster shot against COVID-19, many are putting the necessity of the next dose in question. For some, the extra shots are recommended by the CDC, but this does not mean we should all jump on the vaccine wagon.

Given that almost 1 in every 3.5 Americans have already had a confirmed COVID-19 infection and that our natural immunity is said to be more resilient than a booster shot, there are more ways to bolster your own antiviral immunity.

But does natural infection induce a stronger immunity than a vaccine? If so, why?

Is Natural Immunity Stronger Than the Vaccine?

It’s true that people who have been previously infected with COVID are more resilient against it.
When your body is infected with any virus, it means that our innate immunity is not strong enough to stop the virus at the front line of physical barrier or epithelium layers. As a result, the adaptive immunity will be activated.

In respect to antiviral adaptive immunity, there are two main pathways that can be triggered, the Th1 or Th2 pathway.

Regardless of what type of virus we may confront, a leading Th1 cellular immune response and its downstream cytotoxic T cell antiviral function play a critical role in eradicating the virus from our body. The Th2 pathway with activated B lymphocyte responses takes a secondary or complementary role in the whole antiviral battle.

If Th1 type immune response is not strong enough or Th2 response overweighs the Th1 type response, there is more difficulty in clearing the virus out from our body.

For people who have had a natural COVID infection, their Th1 pathway should have been their   leading responding mechanism to intruding viruses as it secretes plenty of interferons and activates cytotoxic T cells to develop a more comprehensive defense against an incoming heavy infection. A multi-clonal, and rigorous antiviral battle has taken place in the patients, resulting in an enduring immune memory including much longer and much higher level of antibodies.

Whereas, most COVID-19 vaccines are designed to activate the B lymphocyte response rather than Th1 cellular responses. This Th2 pathway activates many B-lymphocytes yet is only a fraction of the whole adaptive immune system.

What the vaccine does is it mainly stimulates the B-lymphocytes through the Th2 pathway, while the complete, natural defense mechanism, namely the combination of Th1 taking the lead and Th2 as an adjutant, can only be developed through a real, natural infection.

This is why current COVID-19 vaccines are, in nature, functionally limited in nature.

The stronger Th1 pathway, induced by a previous infection, also lasts longer. In a cohort study published in the New England Journal of Medicine, immune responses from COVID-19 patients in Nicaragua with a previous infection and those vaccinated were compared. According to the study, “protection was higher against more severe outcomes” in COVID-19 patients infected for the second time.

In this Home Influenza Cohort Study (HICS), 2353 participants in 437 households, with an age range starting with newborn infants to 94 year old adults, were observed for confirmed COVID-19 infection. Vaccinated individuals were excluded from the study.

Using the percent protection formula, which is 100 percent subtracted by the hazard ratio of seropositive and seronegative subjects, the rate of protection against a COVID-19 infection was calculated. The percentage protection are as follows:
  • Prior infection provides a 78.9 percent protection against moderate to severe reinfection
  • Prior infection guarantees a 68.1 percent protection against a symptomatic reinfection
  • Prior infection offers a 63.9 percent protection against any types of second COVID-19
The protection rate against COVID-19 from a previous infection is around 63.9 percent as of October 2021, which is lower than the 93.6 percent protection rate calculated with data back in March 2021. This is likely due to the much longer follow-up period for observed infection as well as the advantages newer COVID-19 variants have over previous strains.
An Israeli study conducted in August 2021 reported that vaccinated individuals, who were not previously infected, were up to 13 times more likely to contract COVID-19 than those already infected during the time when the Delta strain was at its peak.

The study demonstrated that natural immunity confers longer lasting and stronger protection against infection, symptomatic disease, and hospitalization caused by the Delta variant of SARS-CoV-2, yet this likely also applies to newer variants as well.

In this retrospective study, two groups of individuals were compared.
  1. Individuals without a COVID-19 infection history who received two doses of the Pfizer BNT162b2 primary series and who are 16 years and older, count = 673’676
  2. Unvaccinated and previously infected individuals, count = 62’883
After applying three multiple logistic regression models, the study assessed four outcomes: COVID-19 breakthrough infection, symptomatic infection, hospitalization, and death. No deaths were, fortunately, reported during this study.

Compared with the individuals who were unvaccinated and were previously infected (group 2), vaccinated people without a history of COVID-19 infection (group 1) were much more likely to be at risk of infection.

Using the first model, group 1 was around 13 times more likely to have a breakthrough infection, 27 times more likely to have symptoms, and around eight times more likely to be hospitalized when compared to group 2.

The second model predicted that group 1 was about six times more likely to have a breakthrough infection, and about seven times more likely to experience symptoms or be hospitalized when compared with group 2.

This study again reaffirms that our innate immunity provides a more resilient and enduring protection against infection, symptomatic disease, and hospitalization caused by the Delta COVID-19 variant. This study has yet to be officially published, since last August.

Is There Anything to Boost Natural Immunity?

Regardless of the vaccines you take, how healthy you are is still going to play the deciding role against any incoming infections.

Nature is a huge gold mine. There are quite a lot of natural ingredients from medicinal herbs that enhance the Th1 immune response in order to increase their antiviral effects.

One of the many great supplements is spirulina, a blue-green algae reportedly consumed by the Aztecs already during the 16th century. Usually available as a dietary supplement in pharmacies and some supermarkets, spirulina is high in protein, lipids, vitamins, essential amino acids, as well as minerals and many bioactive substances.

Not only spirulina, but many other algae-derived active compounds are widely used due to their antioxidant-rich, antiviral, anti-inflammatory, and immune-enhancing properties. They are beneficial to the point where NASA and the European Space Agency designates them as a must-have for astronauts.
In the March 2021 issue of The International Journal of Applied and Basic Nutritional Sciences, one article was dedicated to evaluate the prospect of spirulina and other algae derived nutraceuticals as a supplement to help combat a COVID-19 infection.

Given that bioactive compounds derived from spirulina contain substantial amounts of natural ACE inhibitors, antioxidants, and antiviral compounds, the use of spirulina will serve to comprehensively bolster the immune system by a long shot.

When spirulina was given to healthy men between ages 40 and 65, their levels of interferons produced by immune cells when stimulated by IL-12, an agent associated with activating the Th1 immune pathway, was much higher than levels from the control group. This means that spirulina as a supplement can effectively boost the natural immune system of the human body in a holistic fashion.

It is very much recommended that you purchase supplements, particularly spirulina but also others, from brands that source their raw materials reasonably, as heavy metal contamination is a considerable issue in this particular dietary supplement.

So now the question remains, should you even get a booster? What about bivalent boosters with that promised Omicron effect? The new booster shots will still help reduce the mortality rate. They will increase your immunity, but boosters, bivalent or not, are still not as effective as a previous infection and a healthy immune system. If you are immunocompromised, then a booster will probably come into question for you to generate antibodies.

However, you should still keep in mind that whichever antibodies generated by whichever vaccines would diminish over time.

In any case, you need to strengthen your own immunity as the starting point. A traditional healthy lifestyle, balanced diet, and positive attitude can work wonders.

Dr. Yuhong Dong is a senior medical columnist for The Epoch Times. She is a former senior medical scientific expert and pharmacovigilance leader at the Novartis headquarters in Switzerland and a four-time Novartis award winner. She has preclinical research experience in virology, immunology, oncology, neurology, and ophthalmology, and also has clinical experience in infectious disease and internal medicine. She earned her MD and a doctorate in infectious diseases at Beijing University in China.
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