5 Immunity Myths You Must Not Believe In The 21st Century

2024 Author: Malcolm Clapton | [email protected]. Last modified: 2023-12-17 03:44

Find out what existing misconceptions about the defense system of our body can seriously harm our health.

Myth # 1. Vaccinations won't help

The introduction of vaccines into the human body is carried out in order to provide it with protection from dangerous pathogens. Vaccination is done to a healthy person in order to "arm" the body in advance with means of fighting infection.

After the components of the vaccines enter the body, the same mechanism is triggered that works when an infection occurs. Immune cells - B-lymphocytes - trigger the production of antibodies, immunity molecules that serve as labels for foreign and help to quickly rid the body of pathogens.

Vaccination does not trigger active actions to destroy the pathogen, since vaccines cannot cause disease. This is a kind of "rehearsal" of the actions of the immune system in response to the ingress of a dangerous infectious agent.

After inoculation and synthesis of the necessary antibodies, the body already "gains time": its B-lymphocytes "remember" which antibodies should be produced when meeting with this or that pathogen. These antibodies will successfully allow the components of the immune system to detect the threat and remove it from the body before the disease develops.

Licensed vaccines are rigorously tested and subject to repeated revisions and reviews once they enter the market.

Vaccination does not give a 100% guarantee that the vaccinated person will not get sick, but this procedure significantly reduces the likelihood of being infected with a dangerous pathogen.

According to the WHO (World Health Organization), every year immunization prevents from two to three million deaths from diphtheria, tetanus, pertussis and measles, and the dangerous variola virus was completely defeated with the help of vaccinations.

Myth No. 2. Children should be kept sterile because they have no immunity

In fact, newborns have immunity, but it develops gradually over several years according to the genetic program embedded in the DNA of Basha S., Surendran N., Pichichero M. Immune responses in neonates. // Expert Rev Clin Immunol. 2014. Vol. 10, No. 9. P. 1171-1184. … It is realized as the child grows up.

While the fetus is in the womb, it is protected by maternal immunity. Lymphoid organs are gradually formed: bone marrow, thymus, accumulations of diffuse lymphoid tissue, lymph nodes, spleen. In addition, immune cells - lymphocytes, neutrophils, eosinophils - are formed in the liver, spleen and bone marrow of the fetus.

In the first three months after the birth of the baby, only maternal antibodies protect against Adkins B., Leclerc C., Marshall-Clarke S. Neonatal adaptive immunity comes of age. // Nat Rev Immunol. 2004. Vol. 4, No. 7. P. 553–564. … The transfer of IgG antibodies occurs in the last trimester of pregnancy. Maternal antibodies degrade over time, and by 3–6 months, many of them cease to function.

The baby's skin, which is sensitive even to minor injuries, is covered with vernix caseosa vernix. This wax-like mixture is secreted by the sebaceous glands. It contains antimicrobial substances - lysozymes, defensins, psoriasins, antimicrobial fatty acids. They all constitute an antimicrobial shield that protects the infant from a wide variety of disease-causing microbes Levy O. Innate immunity of the newborn: basic mechanisms and clinical correlates. // Nat Rev Immunol. 2007. Vol. 7, No. 5. P. 379-390. …

In addition, at the time of birth, Peyer's patches, accumulations of T and B lymphocytes in the mucous membrane, are already present in the intestines of a newborn. When microbes enter, they provoke an immune response and further help to adequately respond to foreign in the digestive tract Reboldi A., Cyster J. G. Peyer's patches: organizing B cell responses at the intestinal frontier. // Immunol Rev. 2016. Vol. 271, No. 1. P. 230–245. …

From birth, a child has a program for the development of the immune system. In order for its maturation to be realized, contact with various antigens and time are required.

Of course, until the immune system is fully strengthened, children are stronger than adults, at risk of contracting this or that infection. However, the desire to create "sterile conditions" for the child threatens the development of hypersensitivity reactions - allergies and autoimmune diseases.

There is a hypothesis about hygiene, according to which the development of such conditions is provoked by insufficient contact with infectious agents, symbiotic microorganisms - representatives of normal microflora and parasites in early childhood. The lack of such contacts leads to a violation of the establishment of immune tolerance - immunity to one's own cells and molecules.

The immunity of children who live in conditions close to sterile may be undeveloped in the future.

Evolutionarily, a person has always received a certain level of load on the immune system in the form of a certain number of pathogens. If the number of surrounding antigens falls, then the body begins to attack harmless particles and compounds. For example, flower pollen or food components can cause the development of an immune response Okada H., Kuhn C., Feillet H., Bach J-F. The 'hygiene hypothesis' for autoimmune and allergic diseases: an update. // ClinExp Immunol. 2010. Vol. 160, No. 1. P. 1-9. …

It is believed that the immune system matures by the age of 12-14, when the same amount of antibodies is produced in a young body as in an adult's body.

Myth No. 3. Immunity is strengthened by yoghurts and multivitamin supplements

There are many recommendations in advertising and media that convince you to buy yoghurts with bacteria, multivitamin complexes, miracle immunostimulants and much more. Unfortunately, there is no ideal and simple recipe for the prevention of infectious diseases.

Let's start with yoghurt. In commercials, we are told that immunity depends on the intestinal microflora, and yoghurts with beneficial bacteria improve the microflora - and therefore the body's immunity.

Today we know that about a thousand species of bacteria live in the human intestine, which play an essential role in the normal functioning of the body. Long-term co-evolution of bacteria and the human body has led to the emergence of complex mechanisms of interaction of the components of immunity with representatives of the microbiome Hillman E. T., Lu H., Yao T., Nakatsu C. H. Microbial ecology along the gastrointestinal tract // Microbes Environ. 2017. Vol. 32, no. 4. P. 300-313. …

The intestinal microflora not only aids digestion and produces the vital B vitamins and vitamin K that our bodies cannot synthesize, but also prevents the entry of pathogenic microbes, maintaining the integrity of the intestinal mucosa and physically preventing them from attaching to intestinal cells.

But the fact is that bacteria from the outside, in particular - beneficial yoghurt bacteria - are not able to stay in the intestines for a long time.

This was confirmed by the American researcher Sherwood Gorbach, who studied bacterial strains for more than 20 years - he could not find bacteria lingering in the intestines in any of the dairy cultures of America, Europe and Asia. If some strains survived after gastric hydrochloric acid, they still disappeared after 1-2 days by Jessica Snyder Sachs. "Germs are good and bad." M., AST: Corpus, 2014.-- 496 p. …

Although today some probiotics have shown promising results in experiments, so far scientists have not enough convincing scientific data on their benefits Sanders ME, Guarner F., Guerrant R., Holt PR, Quigley EM, Sartor RB, Sherman PM, Mayer EA An update on the use and investigation of probiotics in health and disease // Gut. 2013. Vol. 62, no. 5. P. 787-796. …

In the United States, the FDA has not approved a single probiotic for the prevention or treatment of any disease, including those related to the immune system Degnan FH The US Food and Drug Administration and probiotics: regulatory categorization // Clin Infect Dis. 2008. Vol. 46, no. 2: S. 133-136; discussion S. 144-151. …

Maybe multivitamin supplements will help then? Vitamins help to carry out all the most important enzymatic reactions in the body. In total, the human body needs 13 vitamins for normal life: vitamin A, B vitamins (B1, B2, B3, B5, B6, B7, B9, B12), vitamins C, D, E and K Bender D. A. Nutritional biochemistry of the vitamins. Cambridge, U. K.: Cambridge University Press. 2003.488 p. …

Vitamins A, C, D, E, and B6 have been identified as essential participants in immune-related processes. With their lack, the activation of T and B-lymphocytes is impaired, and pro-inflammatory signaling molecules are produced to a greater extent, which in some cases can complicate the pathological processes Mora JR, Iwata M., von Andrian UH Vitamin effects on the immune system: vitamins A and D take center stage // Nat Rev Immunol. 2008. Vol. 8, No. 9, P. 685–698. …

Unfortunately, multivitamin complexes often turn out to be useless, because synthetic vitamins in tablets are absorbed worse or not at all by our body.

Some components of supplements, such as calcium and iron, cannot be absorbed together. In particular, the fat-soluble vitamins A, D, E, and K are often available as tablets that do not contain any lipids required for absorption.

Nutritionists, scientists and experts from reputable organizations such as the WHO and the FDA (Food and Drug Administration) recommend eating well and getting vitamins from food. In case of a lack of vitamins, you need to consult a doctor and review the diet and composition of foods.

Attempts to replenish the supply of vitamins on your own, without consulting a doctor, can be quite dangerous.

According to dozens of scientific studies, daily excessive intake of vitamins can lead to an increased risk of developing various diseases Hamishehkar H., Ranjdoost F., Asgharian P., Mahmoodpoor A., Sanaie S. Vitamins, Are They Safe? // Adv Pharm Bull, 2016. Vol. 6, No. 4. P. 467–477. …

Myth number 4. The brain has no immunity

The brain, like some other tissues and organs - the cornea of the eye, the testes, the thyroid gland - is called an immunoprivileged organ due to the fact that it is isolated from the main components of the immune system by means of the blood-brain barrier. This barrier, among other things, protects the tissues of the organ from contact with blood, which contains cells and immune molecules.

Immune responses in the brain are different from those in the rest of the body. Since the brain is very sensitive to various damage, its immune response is weakened, but this does not mean that there is none at all.

For example, the brain has its own immune cells - microglia are isolated macrophages of the brain that protect organ tissues from infectious agents. When phagocytosis ("eating") pathogens of infections, microglia produces signals that cause inflammation in certain parts of the brain Ribes S., Ebert S., Czesnik D., Regen T., Zeug A., Bukowski S., Mildner A., Eiffert H., Hanisch U.-K., Hammerschmidt S. Toll-like receptor prestimulation increases phagocytosis of Escherichia coli DH5alpha and Escherichia coli K1strains by murine microglial cells. // Infect Immun. 2009. Vol. 77. P. 557-564; Ribes S., Ebert S., Regen T., Agarwal A., Tauber S. C., Czesnik D., Spreer A., Bunkowski S., Eiffert H., Hanisch U.-K. Toll-like receptor stimulation enhances phagocytosis and intracellular killing of nonencapsulated and encapsulated Streptococcus pneumoniae by murine microglia. // Infect Immun. 2010. Vol. 78. P. 865-871. …

It used to be thought that the presence of the immune system in the brain was limited to microglia cells. But in 2017, Dr. Daniel Reich, together with his scientific group, conducted a series of experiments using magnetic resonance imaging and identified lymphatic vessels in the meninges of monkeys and humans Absinta M., Ha S.-K., Nair G., Sati P., Luciano NJ, Palisoc M., Louveau A., Zaghloul KA, Pittaluga S., Kipnis J., Reich DS Human and nonhuman primate meninges harbor lymphatic vessels that can be visualized noninvasively by MRI. // eLife. 2017. Vol. 6. Article e29738. …

In addition to immune cells and lymphatic vessels, immune molecules also play an important role in the normal functioning of the brain. Thus, the cytokine IFN-γ, a signaling molecule that protects against viruses, is involved in the regulation of social behavior.

Scientists from the Universities of Virginia and Massachusetts have identified the relationship of cytokine deficiency with social disorders and impaired neuronal connections, which were also observed in animals with immunodeficiency. This could be eliminated by injecting interferon into the cerebrospinal fluid Filiano AJ, Xu Y., Tustison NJ, Marsh RL, Baker W., Smirnov I., Overall CC, Gadani SP, Turner SD, Weng Z., Peerzade SN, Chen H., Lee KS, Scott MM, Beenhakker MP, Litvak V., Kipnis J. // Nature. 2016. Vol. 535. P. 425-429.

Myth number 5. If the immune system works very actively, then it's always good

Excessive activity of the immune system can be dangerous for the body.

The immune system has the ability to destroy foreign objects, including infectious ones, and rid the body of them. But sometimes the immune system can mistake harmless body cells for a potential pathogen. As a result of an uncontrolled immune response, allergic or hypersensitivity reactions can occur.

According to the classification proposed by British immunologists Philip Jell and Robin Coombs back in 1963, there are four types of such reactions Gell P. G. H., Coombs R. R. A. The classification of allergic reactions underlying disease. // Clinical Aspects of Immunology. Blackwell Science. 1963…. The first three types of hypersensitivity reactions are immediate reactions, since the immune response develops within minutes after contact with the allergen. The fourth type of reaction is characterized by a longer period of development - from several hours to several days.

The material is based on the book "How Immunity Works" by Ekaterina Umnyakova. Man is exposed to billions of microscopic organisms every day. Viruses, bacteria, fungi, protozoa lie in wait for us everywhere.

Fortunately, not all of them pose a threat to our existence, but many can seriously harm our health. This book broadly and understandably talks about how the immune system works, as well as those misconceptions that prevent us from understanding what happens to the body when it is not healthy.