Infectious diseases that are preventable by vaccination do not rest when we get older. In fact, they can be more lethal than in childhood, due to the decline of our immune system . In order to understand this phenomenon, it is first advisable to stop at the concept of immunosenescence. Precisely, this is defined as the gradual deterioration of the different immune functions that a person has due to the vital aging process.
“As a consequence, the individual develops more serious infections more frequently,” explains Fernando Fariñas Guerrero, director of the Institute of Clinical Immunology and Infectious Diseases – belonging to the Ynmun Association.
It is a problem that affects both the production of antibodies and cellular immunity. In this sense, the so-called naive T cells are responsible for responding to new pathogens that the body’s defense system has not yet faced. “Faced with a virus with which we have never had contact, such as the current coronavirus [SARS-CoV-2] or the seasonal flu –which changes every year–, young people have naive or virgin T cells that respond to these new infectious challenges ”, highlights the immunologist. On the contrary, in the elderly, this type of lymphocytes decreases considerably , both in number and in their functionality.
“This means that not only are they unable to kill the new infectious agent in a timely manner, but the invader continues to proliferate . For this reason, the immune system tries to compensate for this lack of response by accumulating more inflammatory cells at the site of infection ”, adds Fariñas. Thus, the inflammatory process, excessive and uncontrolled, causes the organs to begin to fail .
As much as we dislike it, just as skin, bones, and eyes age, so does our immune system . “In addition, in older adults other chronic pathologies are often added, such as hypertension, diabetes and arthritis. Well, if we associate underlying chronic diseases and immunosenescence, it turns out that older people are much more susceptible to infectious processes, ”highlights Isabel Jimeno, head of the Vaccine Working Group of the Spanish Society of General and Family Physicians (SEMG).
Therefore, specialists insist on the importance of vaccinating adults in the same way that it is carried out with children. “We vaccinate minors because we know that in childhood they will have infections. With adults, you have to do it because they are more susceptible to contracting infectious diseases, ”says Jimeno. And with a worse prognosis, too.
What can and should adults be vaccinated with? The Centers for Disease Control and Prevention – CDC, for its acronym in English – recommends vaccinating adults against influenza, tetanus, acellular whooping cough, herpes zoster –the famous shingles–, the human papillomavirus o HPV, pneumococcal disease, and reduced diphtheria toxoid.
“We must remember that the World Health Organization asked in March 2020 that all those countries that already had implemented vaccination programs for influenza, pneumococcus and whooping cough, strengthen these immunizations to the population,” Jimeno says. On the one hand, to free up health and hospital resources against covid-19. On the other, with regard to pneumococcus, to minimize the use of antibiotics , something that is a global threat, since it increases resistance to drugs ”, specifies this specialist.
In this sense, Fariñas insists that the population must be made aware that vaccination is not exclusively for children . “There are diseases that have a very high attack rate in older people, such as pneumococcus, flu, zoster or whooping cough,” says the specialist. And he adds: “Even the meningococcus.”
Vaccination in older adults is from the age of sixty . But experts insist that this is relative. The reason? The loss of immunological efficacy does not affect everyone in the same way, and will depend on the combination of genetics and environmental factors. “Certain elements of the context of the person intervene, such as, for example, nutrition, stress and environmental pollution. All of them contribute to the decline process becoming more or less rapid ”, Fariñas points out. Now, regardless of some age or another, Jimeno wants to make it clear that “you have to be very careful and vaccinate against infectious diseases.”
At the same time, there are autoimmune diseases that precipitate immunosenescence , just as some specific treatments depress the immune system. “This is what happens, for example, to people with rheumatoid arthritis : the effects of new biological treatments block the reach of their immune system. What to do with these patients? Vaccinate them before ”, says the expert.
Something similar happens with patients who suffer from cancer and are going to receive chemotherapy . “If someone contracts a simple cold while undergoing chemotherapy treatment, they immediately become a patient at risk, and will need close supervision. How can we avoid danger? The answer is the same as in the previous case: protect him with the vaccine before starting his treatment ”, recommends Jimeno.
