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Qualified Immunity

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Photo by Magda Ehlers from Pexels

Published in the Humboldt Independent on August 11, 2020

In recent weeks many news stories have been emerging speculating as to whether or not recovered COVID-19 patients are immune to getting the disease a second time. Other stories have come out suggesting that a small number of people who believed they were fully recovered have fallen ill again. Antibody tests are producing unclear and unpredictable results, calling into question the assumption that, as with many viruses, the body develops immunity and cannot be reinfected.

The scientific community has been busy conducting studies, producing numerous papers on all these topics and they all basically boil down to to the fact that we really don’t know yet, but some things are beginning to come into focus, pointing strategies for both vaccine development and treatment in some more specific new directions.

Our immune system

The human immune system has a two-punch attack: the innate system and the adaptive system.

The human immune system has a two-punch attack. The “innate” system handles the inconsequential everyday assaults on your body; minor viruses and bacterial infections. It also has the ability when needed to call on the more advanced and versatile “adaptive” system, which is capable of taking on more serious infections like COVID-19.

The adaptive system can specifically address pathogens not recognized by the innate system. It recruits key agents called B-cells and T-cells to take on more complex tasks.

B-cells work by secreting antibodies that lockout and prevent the disease-causing antigen from binding to and damaging healthy cells. When a person recovers from a disease, it is often the presence of these antibodies that guards against subsequent infection. However, many early studies are showing that there is no predictable presence of these antibodies for recovered COVID-19 patients and that even when they are there, they may not last.

This concern has created the terrifying prospects of not only reinfection in individual patients but also diminished possibility of establishing herd immunity, a much-hoped-for protective community response. In herd immunity, a certain percentage of a population (the exact amount is debated) has recovered from a disease and possesses immunity, thereby making it less likely that a never-infected person will encounter an active spreader.

By now, clickbait will have stirred up a lot of fear about this potential lack of immunity, but science is now finding another aspect of the adaptive immune response that may hold major protection.

You may remember hearing about T-cells during the worst years of the AIDS crisis. Low T-cell counts were a sign that the body was losing its battle, as it became overwhelmed by infections the immune system could normally deal with. The AIDS virus specifically targets T-cells.

B-cells produce antibodies that do not allow re-entry of a virus, T-cells identify the remembered disease quickly and destroy it.

In COVID-19, T-cells can play a part in defeating the disease by specifically targeting infected cells and killing them. In especially severe cases, they can instead be a party to the “cytokine storm“, a phenomenon in immune response in which the body begins to attack its own cells. This is generally seen as a predictor of poor outcome in more advanced cases of the disease, as the immune system turns on itself.

It is in recovered COVID-19 patients that T-cells are showing a different kind of promise of immunity. When they have played a part in recovery, they develop a kind of memory of the antigen that makes their response quick and efficient the next time that particular virus comes calling.

Whereas B-cells produce antibodies that do not allow re-entry of a virus, T-cells identify the remembered disease quickly and destroy it.

Interestingly, some people in the studies who have never been infected with COVID-19 somehow already have T-cells specific to battling the SARS CoV-2 virus that causes COVID-19. More data needs to be collected, but scientists speculate that this could be due to the body having encountered and beaten other coronaviruses closely related to SARS CoV-2, such as the common cold. The T-cells remember those close relatives and know what to do.

Vaccine development can look at both strategies as antibodies and specific T-cells can both be made. As more is understood about individual responses to the virus, the worry about the presence and durability of antibodies alone begins to fade.

Feel better?

Good, but we still have much to learn and while stories splatter the internet about quick vaccine fixes, our cultural penchant for instant gratification may get a slap down. It is still early days.

In the meantime, you may be wondering about how to shore up your immune system so that your response is as protective as possible. As with the Spanish Flu 100 years ago, all kinds of snake-oil peddlers are out there promising protection with all kinds of products. Many are harmless and are even healthy. A good chat with your healthcare provider will guide you toward a nutrition and/or supplement regimen that will give you the best support. Scientific data does show potentially positive effects of three types of nutrients.

  • Vitamin D: deficiency in this nutrient is prevalent throughout the world and low levels are linked to a higher incidence of respiratory infections, as well as the development of autoimmune disease. Ask your provider about checking your levels and what supplementation might be best for you.
  • Probiotics: these microorganisms available in food or supplement form have been shown to reduce the severity and frequency of respiratory infections.
  • Antioxidants: toxic oxygen compounds are released as part of the body’s inflammatory response to infection. A double-edged sword, this process fights disease, but can also damage healthy cells, wearing out the immune system and leading to cancer. Supplementing the body’s reserves of antioxidants with dietary choices of brightly colored fruits and vegetables rich in antioxidants can help prevent the toxic effects. A study of the specific effects of antioxidants on COVID-19 patients is currently being conducted.

Overall, the data shows that one of the best ways to boost your immunity is to reduce stress in your life. Get your rest, eat well, exercise, connect with your loved ones, do things you enjoy, help others when you can.

Together, with patience, we will help each other through this. Wash your hands, wear a mask, and keep that distance.

Ann Constantino, submitted on behalf of the SoHum Health’s Outreach department.