Latin America faced with the challenge of breaking the myth of vaccines in patients with HIV | Health | Magazine

Experts say there are strong arguments for the efficacy of certain disease vaccines in patients with weakened defense systems.

EFE

June 26, 2021 – 5:20 p.m.

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For decades, it was thought that people with compromised immune systems should not receive vaccines that protect against preventable diseases, a myth increasingly debunked by scientific evidence calling for the need to reverse the undervaccination of these patients in Latin America.

Despite the fact that conclusive clinical studies are still scarce, experts maintain that there are strong theoretical arguments about the efficacy of certain vaccines against preventable diseases in patients with weakened defense systems, who are at increased risk of mortality and morbidity.

This group includes people infected with the human immunodeficiency virus (HIV), with which more than 2.1 million citizens of Latin America and 330,000 of the Caribbean live, according to the most recent data from the Pan American Organization of the Health (PAHO), which estimates that 23% of seropositive patients are unaware of their infection.

“Before we took care of patients with immunodeficiencies, including patients with HIV, from vaccines. We believed that they could do them some harm or rather could not provide them with a significant benefit,” the clinical immunological pediatrician Gustavo said in an interview with Efe. Ribbon.

“Today we know that (vaccines) are part of their standards of care” and that HIV-positive patients “constitute a group of people who have specific indications for vaccination,” added the doctor from the National Children’s Hospital of San José, in Costa Rica. .

Reduced efficiency

With the inoculation of vaccines, the immune system learns to defend the body from eventual exposure to an immuno-preventable disease, such as measles, tetanus or the flu, for example.

But, in general, immunocompromised patients, including those infected with HIV, have a lower vaccine response, especially those who do not have full access to antiretroviral treatment, which, according to PAHO, would represent around 40% of the total number of seropositives in Latin America and the Caribbean.

“There are antigens that are very good and attractive in generating a response to the HIV patient and there are others that are less potent and robust,” Lazo said.

This is explained by the fact that the virus that causes AIDS causes an inadequate stimulation of B cells, which generates suboptimal responses to vaccination.

A good set of data shows that HIV patients have a lower immune response capacity with some specific vaccines, such as hepatitis A and B, influenza, pneumococcus, meningococcus, and yellow fever.

In contrast, the evidence is not as strong for others such as Japanese encephalitis, rabies, typhoid fever, polio, cholera, and coronavirus.

Special needs

Even so, experts defend that, in the absence of evidence that contraindicates the need to immunize HIV-positive patients, vaccines should be “part of their treatment”, as long as the precautions and specific needs of this population are taken into account.

“We need vaccines that are quite safe, that are not going to produce significant side effects, that have robust antigens and that receive schedules that are not reduced or abbreviated,” said Lazo.

Specifically, the doctor pointed out that, in some cases, HIV patients require to be inoculated with more doses than those recommended to the general population and that those who do not have a specific minimum number of lymphocytes should refrain from receiving vaccines with live attenuated microorganisms, which could cause adverse effects.

Collective benefit

In this sense, Lazo highlighted the importance of forging a “bubble” around these patients, inoculating their narrowest circle of contacts, and recalled that vaccines not only protect individually, but are rather a “collective benefit” because they reduce the probability of unleashing an epidemic.

“(Vaccination) is a public health strategy, since the idea of ​​applying a vaccine is to achieve collective resistance as a community to a disease,” he stressed.

He added that practices such as prioritizing the immunization of HIV patients in vaccination campaigns against covid-19 show that the region is on a path that should allow it to definitively destroy the myth about the supposed ineffectiveness of vaccines in this population.

“What we are failing, perhaps, is in designing concrete strategies for these groups of patients, who have specific needs,” criticized the doctor. (I)

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