8 Myths About Immunity

In the 19th century, when microbiology was just emerging, two scientists — Russian biologist Ilya Mechnikov and French experimental chemist Louis Pasteur — almost simultaneously came to the idea that the body is capable of resisting microbial invasion. It was at that time that the term “immunity” appeared — the body's ability to recognize an intruder and eliminate the threat.

At first, however, immunity was understood as the body's resistance to infectious diseases. But by the mid-20th century, research had proven that the system's tasks are much broader: immunity protects the body not only from microbes but also from any other genetically foreign cells (parasites, foreign tissues used in transplants, as well as the body's own tumor cells).

Two Lines of Defense: Innate and Acquired

• Innate (hereditary) immunity is the inborn ability to destroy foreign invaders. It acts as both a brick wall and an alarm system. The skin, mucus, acidic gastric juice, and beneficial microbiota are the first sentinels. If a microbe breaks through, it is met by phagocytes and “natural killers,” capable of destroying an infected cell in mere minutes. Inflammation occurs: the temperature rises, blood rushes to the affected area, and cleanup begins.
• Acquired (adaptive) immunity is developed after real “combat” (i.e., direct encounter with an infection) or after a “major training exercise” (i.e., fighting a weakened pathogen introduced via vaccination). This type of immunity forms long-term memory — this is why chickenpox usually occurs only once in a lifetime, and vaccines can protect for many years.

While hereditary immunity stays with us for life, adaptive immunity sometimes lasts a lifetime, and sometimes only for a few years or one to two years, as after the flu.

Step by Step: How an Immune Battle Unfolds

1. Physical Barrier. Even the most “ordinary” saliva contains an enzyme that breaks down bacterial walls, and the secretions in the respiratory tract have antiseptic properties.
2. Chemical Alarm. A microbe that breaks through encounters a phagocyte, which engulfs it and immediately releases signaling molecules called cytokines. These “beacons” attract reinforcements and trigger the classic signs of inflammation — heat, redness, swelling.
3. Passing to Intelligence. Dendritic cells, like photojournalists, deliver “snapshots” of the antigen to the nearest lymph node. There, lymphocytes select the right weapon for every detail.
4. Precision Strike. Antibodies block viruses, clump bacteria together, and mark targets for the complement system. Cytotoxic T-cells destroy infected cells before a new viral “assembly line” can form inside them.
5. Archive Formation. After victory, a small but highly trained group of memory cells remains. In case of a repeat attack, they launch an “emergency protocol,” cutting the mobilization time from days to mere hours.

Myths That Hinder Understanding of Immunity

Since the immune system is extremely complex and still under study, even among doctors there are often misconceptions about immunity. Needless to say, ordinary people without medical education are even more prone to misunderstandings. Therefore, we propose to examine the main misconceptions and myths about immunity.

Myth 1: All Diseases Are Caused by a Weakened Immune System

Of course, the immune system is one of the most important systems of the human body. However, statements claiming that all diseases are due to a “weakened immune system” are not entirely correct. One could just as well say that “all diseases are caused by nerves.” To some extent, that would also be true, but usually, several factors are needed for a disease to develop. A weakened immune system can be one of those factors.

There are also diseases that develop independently of the immune system's condition but later lead to its weakening (an example of such a disease is diabetes mellitus).

Myth 2: To Prevent Illness, You Need to Take Medicines That Boost Immunity

Today, pharmacies offer a multitude of drugs claiming to “strengthen the immune system.” In reality, however, specialists use no more than 20 such medications. But perhaps the most important point is that none of them are used as standalone treatments. They are prescribed only — let us emphasize, only — as part of a comprehensive therapy for a specific illness. As you can see, there is no question of prevention here.

According to experts, it is practically impossible to strengthen the immune system of a healthy person with medication for the simple reason that such drugs exhibit therapeutic and preventive effects only in sick individuals and only within comprehensive treatment. However, it is quite possible to harm the immune system by taking these drugs improperly. The chemical balance in the body is a delicate and fragile mechanism.

It is important to remember that healthy people do not need to take such medications. Immunomodulators are highly effective medicines, but they have strict indications for use. They offer protective, preventive effects only in sick patients and only when used as part of complex therapy. It is impossible to stockpile health for the future.

Everyone should use common sense, especially when confronted with yet another “miracle cure” claiming to “heal everything.” Behind most so-called miracles in medicine usually lies simple charlatanism and the desire to profit from someone else's misfortune.

Myth 3: The Immune System Can Handle Infectious Diseases on Its Own, So There’s No Need for Treatment

To some extent, this is true, as the immune system can indeed handle many viruses and bacteria. But unfortunately, even a very well-functioning immune system may not withstand large quantities of viruses or bacteria, or even a small amount of highly pathogenic agents such as cholera, typhoid fever, dysentery, measles, and certain other diseases.

And if microorganisms manage to overcome all the protective barriers erected by the immune system, then medical help is needed to treat the disease that has begun. Treatment should be chosen based on the situation. Sometimes it is enough to use supportive, general strengthening remedies to help the immune system neutralize the pathogen faster (for example, taking vitamins during a cold). Sometimes antibacterial drugs, etiological therapy (targeting the elimination of the pathogen), or immunocorrective therapy are necessary.

Myth 4: Immunodeficiency Diagnostics Should Be the First Priority During Medical Check-Ups

This is not necessarily the case. Often, such diagnostics are promoted because they are costly and profitable for many private centers.

The main signs of immune system issues are frequent recurrences of chronic diseases or frequent colds that do not respond to treatment. But even that is not enough to suspect an immunodeficiency. Immunological tests should only be conducted when these problems persist despite adequate and timely treatment. If a person does not treat their cold properly, or if prescribed treatments prove ineffective, the problem likely lies elsewhere, not in the immune system.

Myth 5: All Immune Drugs Enhance Immunity

This statement is incorrect. Besides immune-boosting drugs, there are also immune-suppressing drugs known as immunosuppressants. They are used in modern medicine, for example, during organ transplants to prevent the body from rejecting the transplanted organ.

Myth 6: Taking General Strengthening Remedies with Nonspecific Action Solves All Immune System Problems

Such a claim can indeed sometimes be found in popular science literature.

However, in reality, the situation is much more complex. Of course, vitamins, adaptogens (such as ginseng and eleutherococcus), hardening procedures, optimal physical activity, and so on do strengthen health. But often, this is not enough when the immune system faces a serious challenge.

In many cases (pneumonia, tonsillitis, allergies, and others), deeper intervention into the immune system’s work is necessary, and consulting a doctor is advisable. Self-medication in such cases can lead to ineffectiveness or side effects.

Myth 7: Only Immune Drugs Affect the Immune System

Those who think this way are mistaken. Any chemical substances can influence immunity. The difference is that such effects can be either suppressive or stimulating. It should be noted that with prolonged use, almost any medication can lead to a weakening of the immune system. Therefore, it is advisable to take preventive measures to support the normal functioning of the body's defenses.

Myth 8: Immunity Does Not Form Against Recurrent Diseases

It is well known that there are diseases (such as chickenpox, measles, or rubella) that a person typically contracts only once in a lifetime, after which the body develops immunity against them (adaptive immunity). At the same time, many people believe that immunity does not form against diseases that can recur.

This opinion is incorrect because our immune system “remembers” all the microorganisms it has encountered. The antibodies produced against them remain in the body for a long time, sometimes for life. Therefore, if the pathogen enters the body again, the disease may still develop, but the immune system already knows how to fight it, making the illness much milder.

Immunologists note that if the immune system were unable to protect a person in this way, people would constantly be sick.

What Truly Strengthens Immunity

• Vaccination. A vaccine is a safe training ground for lymphocyte armies. It is better to train on a simulation field than in a real battle.
• At least seven hours of sleep. During deep sleep phases, the brain releases hormones that enhance the activity of natural killers.
• Moderate daily exercise. Aerobic activities — walking, swimming, cycling — boost blood circulation, speed up immune cell circulation, and reduce chronic inflammation levels.
• A diet focused on whole foods. Fiber, fermented foods, fish, nuts, and vegetable oils provide building materials for antibodies and support friendly microbiota.
• Stress management. Breathing techniques, yoga, meditation, and social support lower cortisol levels. High cortisol suppresses lymphocyte function and damages mucosal barriers.
• Responsible use of antibiotics. Only as prescribed by a doctor and always completing the full course. Otherwise, bacterial resistance increases, and the microbiota suffers.
• Quitting smoking and moderate alcohol consumption. Tobacco smoke toxins and ethanol damage mucous membranes, suppress phagocytosis, and alter the microbiota composition.

Curious Facts to Broaden Your Horizons

1. Humans have the longest-lasting antibodies. In people vaccinated against smallpox, antibodies and T-cells capable of recognizing the virus persisted for 1 to 75 years after vaccination, essentially for a lifetime — a rare example of truly “eternal” immunity.
2. Sea urchins have been found to possess more than 200 pathogen-recognizing receptor genes — five times more than humans.
3. Children who grow up with pets are less likely to suffer from allergies: early “educational” contact with microbes teaches the immune system to distinguish threats from harmless agents.
4. City dwellers raised without contact with pets have a higher risk of developing allergies.
5. As people age, immune aging occurs — lymphocytes lose their plasticity, and low-level inflammation (“inflammaging”) increases. Regular physical activity and balanced nutrition can slow this process.
6. Just one sleepless night is enough to weaken natural killers. After partial sleep deprivation, their cytotoxic activity drops by about 30% and recovers only after a full day of proper rest.
7. Chronic stress switches the immune defense to “economy mode.” Constantly elevated cortisol suppresses white blood cell production and reduces antibody production, making a person more vulnerable to infections and slowing wound healing.

Immunity is not a magical “box” that can be “boosted” with a single pill but a complex network of cells, signals, and barriers. It has an amazing ability to learn and remember, but it needs resources: sleep, exercise, quality food, absence of toxins, and timely vaccination.

If illnesses become frequent or severe, the main strategy is not to look for a miracle pill but to consult a specialist who can identify the cause and select precise treatment.