A weakened immune system will not respond properly to vaccination. This is especially true for the elderly and the chronically ill. Immunologists say that as you age, your immune system "wears out". - said prof. Piotr Trzonkowski, immunologist from the Medical University of Gdańsk.
Prof. Piotr Trzonkowski participated in an online debate organized by the Foundation for Polish Science en titled: "Why do properly vaccinated people sometimes suffer from COVID-19?". The expert recalled the natural process of aging, which affects the effectiveness of medical treatments, including vaccinations.
"Immunologists say that with age the immune system + wears out +. As we age, we lose the thymus - the organ that produces T cells - responsible for cellular immunity in the body. They also help to generate immunity after vaccination "- said prof. Trzonkowski. He also referred to another mechanism that regulates the response of the immune system - the so-called "Pro-inflammatory readiness of the body".
"Older people have a high level of pro-inflammatory cytokines in the body, responsible for the so-called 'Cytokine storm'. If we were to compare a 20-year-old and an 80-year-old, the normal, physiological levels of pro-inflammatory cytokines in an 80-year-old are so high that they would cause sepsis in a 20-year-old. So the willingness to enter a cytokine storm and hemorrhagic pneumonia after infection is much greater. These are the reasons why the elderly react poorly to vaccinations, and when they become ill, they become seriously ill "- he explained. He recalled that the main role of the vaccine is to protect against hospitalization and death. "There has been a study of 100-year-olds in Italy that shows that the elderly get sick, but the vaccine - in this case the flu vaccine - protects them from death," said Prof. Trzonkowski.
The immunologist also discussed the cases of chronically ill young people whose immune system does not respond to vaccination. “Here the conditions are dictated by the nature of the disease. In some patients who take immunosuppressive drugs, the immune system will not respond because the drugs inhibit its action "- said prof. Trzonkowski.
As he added, he was surprised by the difficult situation of kidney patients. “In a pandemic, she surprised methe situation of people with chronic renal failure - these are people who are practically helpless when it comes to contact with the SARS-CoV-2 virus. The first reports even before the vaccine appeared, said that 25 percent. people on dialysis died after being infected with the coronavirus. Our research shows that immunization in these people produces immunity and is worth getting vaccinated. Therefore, the fourth dose is already available for these people, which significantly increases the effectiveness of vaccinations "- said Prof. Trzonkowski.
During the meeting, prof. Michał Witt, a geneticist and molecular biologist, director of the Institute of Human Genetics of the Polish Academy of Sciences in Poznań, reminded that one should not expect 100 percent. the effectiveness of any vaccine.
"Medicine has not found such drugs that would work 100 percent. We'd love to do that, but it hasn't happened yet. We know that vaccines on the market have a limited mode of action. We know that the flu vaccine is 40-60 percent effective, the tetanus vaccine is 90 percent effective, and the pertussis vaccine is 70 percent effective. These ranges are different in each case "- mentioned prof. Witt. He also added textbook information on genetics to help understand why everyone responds differently to medications and vaccinations.
"Genetics mean that each of us is different and each of us has a different equipment - a different genetic profile - also in terms of genes that determine immune resistance. That is why we react differently. You also have to take into account the lifestyle we are at and what other diseases we are struggling with. The immune system does not work the same all the time - it has its ups and downs - depending on how and with what it is attacked (eg with other infections) "- said Prof. Michał Witt.
The debate took place as part of the "Let's trust science" campaign - a cycle initiated by the Foundation for Polish Science in 2022.