Coronavac: lower immune response for those over 55 years old – National

(photo: Helia Scheppa/SEI - 05/8/21)
(photo: Helia Scheppa/SEI – 05/8/21)

The immune response against COVID-19 in most men over 55 years vaccinated with two doses of CoronaVac is less intense. This is the preliminary result of a study coordinated by the Faculty of Medicine of the University of So Paulo (USP) and published this week.

From the analysis of blood samples, the survey indicated that only a third of men above this age group had a strong response against the coronavirus. The survey observes that the reaction to the pathogen drops significantly after the age of 80 years.

In the article, scientists recommend the application of a third dose of Coronavac against COVID-19. First in elderly people over 80 years of age, and, when possible, in people over 60. “The study was carried out by collecting blood from 70 people who were convalescent, vaccinated with two doses of CoronaVac in the minimum interval of four weeks to be done,” explained Jorge Kalil, from the USP Medical School, one of the authors of the study.

According to Kalil, three parameters were verified: the antibody response to coronavirus proteins; antibodies that inactivate the virus; and the cellular response, whose action occurs through the proliferation of defense cells (lymphocytes).

Co-author of the study, Edcio Cunha Neto, also from the Faculty of Medicine, stated that the production of two proteins, interferon-gamma and interleukin-2, which are important for the functioning of T cells (which defend the body) was measured. Only interleukin-2 showed changes, “which points to a possible difficulty in the production of memory T cells, which guarantee the immune response against the virus long after vaccination”.

Despite the USP study, CoronaVac proved to be efficient. In May, the Butantan Institute vaccinated, with two doses, the entire adult population of the municipality of Serrana (SP). The project showed that symptomatic cases of the disease dropped 80% and deaths dropped 90%.

*Intern under the supervision of Fabio Grecchi

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