Research carried out with the population of São José do Rio Preto, in the interior of São Paulo, showed that while 32.9% of people between 10 and 40 years old do not have immunity against measles, the presence of antibodies in the group over 50 reaches 99 %. Supported by the São Paulo State Research Support Foundation (Fapesp), the study tested 981 people, of various age groups.
Considering the total number of individuals who were vaccinated against rubella and mumps, 39.3% had no immunity against measles and 20.2% had no immunity to rubella. For the research coordinator Maurício Lacerda Nogueira, professor at the São José do Rio Preto School of Medicine (Famerp) and former president of the Brazilian Society of Virology, these percentages are sufficient to protect the population from rubella, but not from measles. The combined vaccine against measles, rubella and mumps is part of the national vaccination schedule in the country.
“The main finding of the work is that you have a range of the population that is discovered for vaccination, a population that is susceptible, that is the main responsible for example of the measles epidemic that we had last year. In other words, a large age group below 40 years old is susceptible and is capable of sustaining a measles transmission within this population ”, said the researcher.
The main problem with these percentages is that it allows the transmission of measles in the population. “What’s more, sustained transmission will allow the virus to reach an age group, for example, where children are not yet vaccinated. So it is dangerous for you to leave an airborne disease that is passive for vaccination in such a vulnerable state, ”he said.
The study suggests, according to Nogueira, that there is a correlation between the creation of antibodies, vaccination and the individual’s exposure to the virus. Individuals over 50, who had lifelong exposure to the virus, had a higher percentage of immunity than younger people, even vaccinated.
“We can say that there is a group of people who are not vaccinating and we also believe that there has been a lack of the booster [reforço] that is, when the virus circulated naturally, it also ended up boosting [impulso], making that immunity remain. A part of this population is vaccinating, but over time it is losing detectable antibodies ”, he concluded.
The data revealed by the research are not just a result of the lack of vaccination and this rate of absence of antibodies needs to be investigated, according to Nogueira. However, he points out that vaccination, not only in children, but also in adults, is a great resource to combat this low immunity that people have against measles and that cannot be ruled out.
“The main action is vaccination, we have a vaccine, we have an efficient vaccine, at least because of the data we have. So it is essential that this vaccine coverage goes up to more than 95% ”, he evaluated. (ABr)