At least 500,000 children in the country have not been vaccinated against polio. The large number of people without protection from the disease has made PAHO (Pan American Health Organization) put Brazil on the list of eight Latin American countries at high risk of returning the infection. In more severe cases, the disease can cause paralysis.
According to PAHO, the WHO (World Health Organization) arm in the Americas, low vaccination rates in these countries are a danger to all of Latin America. The region has not registered a single case of the disease since 1994.
Brazil, which previously had 95% coverage of the polio vaccine, now has one of the lowest rates in its history, 67%, according to researcher Akira Homma, senior scientific advisor for Bio-Manguinhos, in Fiocruz. He was one of the people responsible for eradicating the disease from the country in the 1980s.
“We now have 500,000 children in the country who have not been vaccinated,” Homma said in an interview with Stay. “This number is very worrying, especially because we are close to two countries at high risk of infection, Haiti and Bolivia.”
In Brazil, according to the PNI (National Immunization Program), children should be vaccinated against the virus (inactivated virus) at the age of two, four and six months.
Next, two doses of oral vaccination agent (live attenuated virus) are taken, the first at the age of 15 months and another at the age of four years. According to official statistics, 67% of children had all three doses of the vaccine injected. Oral vaccine coverage is even lower: 53%.
This does not mean that half of the children are totally vulnerable. Even with the two regimes incomplete, the minors have some degree of protection.
From a public health point of view, however, as Homma explains, the ideal is for all children to have both complete diets precisely to prevent the circulation of the virus and possible mutations.
Injectable polio vaccines have been available in Brazil since 1973. But it was not until the 1980s, with the introduction of the oral vaccine and the national vaccination campaign (created by Zé Gotinha in these actions), that the disease was finally eradicated in 1989. . .
“We had the mobilization of the whole society,” Homma recalls. “We managed to vaccinate 18 million children in one day.”
In a note, the Ministry of Health reported that “it has closely monitored the vaccination coverage and has worked to intensify the strategies needed to reverse the scenario of low coverage”.
The folder also reported that it recommends states, municipalities and the Federal District to conduct active vaccination research and reinforce the importance of maintaining routine vaccination actions.
The ministry also said that disseminating information on vaccine safety and efficacy as a measure of public health is also part of the actions taken throughout the year.
Has polio vaccination coverage never been so low?
Unfortunately, coverage not only of polio, but of all vaccines has gradually fallen for five or six years, and more severely, in the years of the pandemic, even due to the recommendations of social isolation.
But the truth is that protection has already fallen, not only in Brazil but all over the world. In 2019, the World Health Organization named low vaccine coverage as one of the top ten public health issues in the world.
The situation is very serious and worrying because the so-called susceptible population is growing. Four weeks ago, we had a polio case in Malawi, which is considered a polio-free country.
More recently we have had another case of polio in Israel, which is traditionally a country with high vaccination coverage. Both times were imported cases.
Is there a real risk of polio returning to Brazil?
Yes, polio imports exist and, in Brazil, due to the low vaccine coverage, we are already considered a high-risk country for reinfection, according to the Pan American Health Organization classification.
Similar to Brazil, Ecuador, Venezuela, Guatemala, the Dominican Republic and Suriname in this classification, in addition to other countries where the risk is considered very high: Haiti and Bolivia. We are surrounded by countries at risk of re-infection, and polio was considered eradicated throughout Latin America in 1994.
Is polio still endemic in any country?
In Pakistan and Afghanistan. But the biggest problem is that there are other countries in the Middle East and Africa where, due to low coverage, polio and live attenuated viruses from vaccines may appear.
Could you explain exactly how this mechanism works?
The Sabin vaccine (immunized oral polio) is made with live attenuated virus. The vaccinated child spreads the virus to the environment.
With very low vaccination coverage, this virus can start circulating among unvaccinated people. The more a virus circulates, the more it mutates, and it can become a new threat, as if it were a wild virus.
If the vaccination coverage of the population was 95%, there would be no problem. But with such low coverage, it becomes a risk. In the case of Brazil, the coverage of the injectable vaccine is 67%; that is, we have more than 30% of children who have not been vaccinated.
There are nearly 500,000 unprotected children. That is why OPS has placed Brazil among the countries at high risk of polio return. The number is even more worrying because we are close to two countries at high risk of becoming infected, Haiti and Bolivia.
In your analysis, what are the reasons for such protection?
There are many reasons, there are many published works. One of the main reasons is that we are victims of our own success.
As we no longer have epidemics, the population does not see more cases, people do not see the sick, and people do not think they need vaccinations anymore.
It would not be necessary if the disease were completely eradicated worldwide, but as long as there are countries with polio, we must continue to vaccinate children precisely to prevent the wild-type virus from entering the country, especially with high susceptibility.
But I also think that there is a need to better inform the population about the situation of polio, call people to be vaccinated, this transparent information no longer exists.
There are also other issues that the population has noticed, such as the opening hours of health centers that coincide with working hours.
And what is the solution?
We are proposing a project to restore strong vaccine protection at work in the corner, in the municipalities, where vaccination protagonists are located.
We will follow daily routines in 41 municipalities in two states, Amapá and Paraíba, and based on these observations we will prepare a specific action plan for each city. The idea is to expand to the rest of the country.
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