Diagnosed at the age of three, Ana Lúcia Cunha was too young to remember clearly what it was like to be a patient with poliomyelitis in 1970. But her right leg lost mobility and did not allow her to forget the consequences. Although struggling to learn how to deal with her condition, the public servant has been an advocate of vaccination, so that others do not go through what she did. Known as “infantile palsy” or simply “polio”, the disease is transmitted by viruses and affects mainly children under five years of age.
According to the World Health Organization (WHO), one in every 200 polio infections leads to irreversible paralysis, usually of the legs. Due to massive vaccination, since 1994 the country has received and maintains the disease eradication certificate, issued by the WHO.
However, the low vaccination coverage recorded in recent years brings the warning of a risk of polio resurgence. This year, in early October, there was a suspicion of infection in Pará, but, after an investigation by the health authorities, this hypothesis was discarded. Thus, the country remains polio-free.
Only 70% of children aged 6 months to 4 years old were immunized in the country, during the National Vaccination Campaign against poliomyelitis, until October 26, 2022 - in the Amazon the rate is 63%. The Ministry of Health's goal for this campaign is to vaccinate 95% of the target group.
For Ana Lúcia, each citizen has an important role in guiding parents and children themselves to encourage vaccination. Now, 54 years old, she is a public servant and mother of two children. “When my children's colleagues commented on my walking on crutches, I explained that I was like that because I didn't take the 'drop' and I used to ask: 'Have you taken it?'”, she recalls, referring to the oral polio vaccine (OPV) – the second dose of immunization against poliomyelitis administered in the Brazilian vaccination schedule.
Access to vaccination in Brazil was expanded in 1973, with the formulation of Programa Nacional de Imunizações (PNI) [National Immunization Program]. Three years earlier, however, the reality was different, especially in the Amazon. Ana was born and lived in the municipality of Xapuri, in the interior of Acre state, where her parents were rubber tappers. She recalls that “at that time, vaccination was not easily accessible, and we had not even heard of poliomyelitis”. The first symptom was an intense and incessant fever. She was hospitalized for a month in the state capital, Rio Branco, and her mother says that, during this period, the vaccination reached her community and Ana’s younger sister managed to receive the immunizer. “I narrowly missed out on the vaccine, for just a few days”, she regrets.
Polio is totally preventable with vaccines
According to the Pan American Health Organization (PAHO), polio can spread rapidly among communities with insufficient vaccination coverage: when the rate drops below 80% in a region or country, there is a high or very high risk of experiencing an outbreak. Although there is no cure, with vaccines, it is a completely preventable disease.
In Brazil, the vaccination coverage rate has been falling since 2015. And this is drastically reflected in the Amazon. The worst rate in the country regarding poliomyelitis is in Acre, with only 38.68% of the target audience immunized until October 26, 2022.
Sequelae can appear over a decade ahead the contagion
In the past few decades, researchers have discovered post-polio syndrome (PPS), a nervous system disorder that strikes people only over a decade after the disease. The symptoms, the period when it will affect, and even if PPS will strike or not, will vary according to each case, but the main complaints are muscle pain, weakness, excessive tiredness and cramps.
“Many still don't know the SPP. There are people who have post-polio symptoms and don't know what it is, they think it's just aging, so we inform and show them where they can get specialized medical treatment”, explains Andrea Caselli, a member of the fiscal council of Associação G-14 de Apoio aos Pacientes de Poliomielite e Pós-Pólio [Association of Support for Poliomyelitis and Post-Polio Patients]. Andrea got infected with polio virus in childhood, at the age of 10 months. "We lived at that time in Macapá (Amapá), in 1968. We didn't even have 24-hour energy, not even in the health centers, thus it was not so easy to be vaccinated. My mother had never heard of polio and my father was not very prone to vaccination," she says.
Brazilian Health System is a world reference
The Sistema Único de Saúde (SUS) [Unified Health System] recommends more than 20 vaccines that must be taken by citizens along their lifetime. All vaccines are offered free of charge and may be monitored by the vaccination booklet, a document that is received since a baby is born and where immunization records are kept, with administered doses dates and the agenda of the next vaccination periods.
“In many parts of the world, vaccination is charged, as in the United States. Only during the covid-19 campaign, due to the pandemic, which was a particular case, it was not charged", emphasizes nurse Ilma Pastana, vice rector of the University of the State of Pará (UEPA). According to her, this is one of the reasons why SUS and the Brazilian vaccination scheme are worldwide references. “In addition to achieving great vaccination coverage, reaching remote communities, always free of charge, there is a whole range of professional training around and integration with the academia, which constantly join efforts to improve this system”, she adds.
Conversely, private clinics in Brazil charge, on average, R$ 150.00 for the flu vaccine; R$ 550.00 for the HPV vaccine and, and some immunizers, such as covid-19, may not even be available outside the public system.
Low vaccination coverage led to measles recurrence
According to the Ministry of Health, three of the five states with the lowest rate of vaccinated population in Brazil are located in the Amazon region. Currently, only about 40% of the region's population is up to date with the vaccines provided for by the PNI. Ten years ago, this rate was 77.72% (2012 data available on DataSus). “If we look back, 10, 20 years ago, we realize we were able to overcome barriers, even in the Amazon – a region full of particularities, such as geographical distances. What has changed for us to get to this point?”, asks doctor Amanda Alecrim, representative of Sociedade Brasileira de Imunizações (SBIm) [Brazilian Society of Immunizations] in Amazonas.
In her opinion, one of the factors for the decline in vaccination coverage is the fact that the younger generation of mothers and fathers, aged between 20 and 30, did not grow up with the “fear” of “infantile paralysis” and, therefore, may not realize the seriousness of the disease. “But it is important to underline that, even when the disease is eradicated, the virus is not eliminated from the planet. So, even if Brazil has eradicated 'polio', when we lower our vaccination coverage, it's as if we open the door of our homes for the virus, which hovers around, to attack us again”, she illustrates.
That is what happened with measles, considered an eradicated disease in Brazil in 2016. It is in fact a disease that needs to maintain its vaccination coverage rate at 95% of the target population. However, in 2017, the percentage of vaccinated people was 84.9% with the first dose, and 71.5% with the second, according to the Ministry of Health. A year later, in 2018, the disease has again become a concern in the country, after two outbreaks in the Amazon (in the states of Roraima and Amazonas) and, since then, the country has continued to report cases. From 2018 to August 2022, more than 39,000 cases were reported across the country from which 15,574 were in the Amazon.
“Fake News” and lack of national campaigns lead to low vaccine coverage
Doctor Amanda Alecrim explains that the increase in the spread of false information, called “Fake News”, on the internet and messaging apps, is one of the factors already identified to foster the constant drops in vaccination numbers. “Currently, there is a very strong anti-vaccine movement that blinds the population and spreads false information about the safety of vaccines. What we advise, as SBIm representatives, is that this kind of information should always be checked on reliable websites, such as those from OPAS [Pan American Health Organization] and the Ministry of Health”, she adds.
In addition, each municipality may set up its own "D-Day", that is, the day when vaccination is intensified during a campaign period – unlike what happened in the recent past, when the entire country standardized the vaccination process all on a same date. "The lack of unity of the campaign can be confusing and a decisive factor", according to the doctor. Due to the difficulties of transportation and distances in some communities, if someone goes to the urban center believing that it is the right day for the immunization and, in fact, it is not, “that person does not come back on another day to get vaccinated”, she exemplifies.
The working hours of the health units also need to be re-evaluated. “The current reality is that both mothers and fathers work outside home and health unit hours, usually from 8 am to 5 pm, do not match this routine. It is important to rethink this strategy and, in parallel, company managers need to set employees off earlier to take children to be vaccinated”.
Diseases such as meningitis are already a concern in other regions
Among the vaccines available at SUS, there are immunizations against hepatitis, mumps, rubella and meningitis, diseases that have already been a plague in the past, but in the 21st century have become less common. However, due to the low vaccination coverage, there has been an outbreak of meningitis in the country in recent months. Symptoms include high fever, malaise, vomiting, severe headache with neck pain, and difficulty touching the chin on the chest.
The outbreak has been concentrated in São Paulo, Minas Gerais and Rio de Janeiro, but an increase in cases has also been reported in Espírito Santo, Pernambuco, Bahia and Santa Catarina – states where vaccination coverage against meningitis is below 60%, considering Meningococcal C vaccination (including the 1st booster dose). In the Amazon, the average rate is 45.92%, with lower rates in Amapá (32.90%) and Roraima (35.93%). Vaccination is the best form of prevention. The usual target audience are children from 12 months of age on, who receive extra doses at 5 and 11 years old.
As a reaction to the recent outbreak, the Ministry of Health is also temporarily making available another type of meningococcal vaccination, the ACWY, which protects from more variations of the disease compared to meningococcal C vaccination. Until June 2023, adolescents aged 11 to 14 who were not vaccinated against meningitis in childhood will be able to receive the immunizer in vaccination spots around the country.
The general guideline for families at the moment is to confirm everyone has had full immunization. Otherwise, they should look for the nearest health unit.
Adults - Another concern, according to doctor Alecrim, is the dropout rate among adults. “That is, people who during childhood took all the vaccines correctly, but when they reach adulthood, they lose this control”, she states. In the Amazon, the current dropout rate is of 25.49% (higher than the national average of 15.19%). “It's never too late to update your vaccination book. If you are in doubt if any immunization is missing, go to the nearest health unit with your vaccination report card and you will be correctly oriented”, explains Amanda Alecrim.
Vaccination in the Amazon requires different strategies
Concerning vaccination strategies in the Amazon, it is also necessary to consider the geographical distances between communities in rural areas or in the middle of the forest, as Virgílio Viana, general superintendent of the Fundação Amazônia Sustentável (FAS) [Sustainable Amazon Foundation] emphasizes.
FAS coordinates the “SUS na Floresta” program [SUS in the Forest], which carried out a pilot project last year, in partnership with the Government of Amazonas, taking vaccines according to each riverine and indigenous community, and not by age group or priority groups, such as the nationally adopted strategy. The method was designed to better serve the population and save time and money. “Imagine having to visit each residence, in each community, on the long stretch of a river, to vaccine one age group and then returning all the way again for another age group”, he exemplifies. “It was an experience that worked very well, and we now know that this can be a way to expand vaccination in the region for other immunizers as well”, adds the superintendent.
Researchers seek new vaccines against malaria
Along with the effort of the health system to immunize the population with existing vaccines, science is working on the development of new immunizers. Several teams in the world have been working on new vaccines against malaria, an infectious, febrile, acute and potentially serious disease that is acquired after the bite of a mosquito that transmits the Plasmodium parasite.
About 99.9% of malaria transmission in Brazil occurs in the Amazon. In 2021, 1,742 outbreaks were reported in the region. The parasite has different species, but the only malaria vaccine available on the market currently protects against the disease caused by the protozoan Plasmodium Falciparum and is employed in some countries in Africa which present a high rate of transmission of the disease. However, in Brazil, this vaccine is not available, taking into account the biggest threat is Plasmodium Vivax, which represented 83% of cases in 2021 in the country.
Therefore, the Ministry of Health in Brazil has focused its debates on the P.Vivax vaccines. An example of such effort is the research underway by scientists at Universidade de São Paulo who are pursuing the production of an immunizing with the variants of this species. Clinical trials should start in 2023 and, if the results are positive and the vaccine come into circulation in the future, it should be a more effective protection measure for the Brazilian Amazon.
Prevention of tropical diseases
According to the Ministry of Health, factors such as high temperature, heavy rain and the high presence of mosquitoes are some of the reasons for the Amazon region to be considered endemic for tropical diseases, such as malaria and yellow fever, the vaccine for the latter is also available in SUS, and since April 2017, it is only necessary to take one dose for a lifetime. Despite the number of cases being controlled, the alert for yellow fever is that about 20% to 50% of people who develop severe yellow fever can die: in the Amazon, only two cases were confirmed in 2020, but both led to death. Immunization is crucial and the best form of prevention.
Concerning Dengue disease, despite the highest incidence number in the Centralwest region, there are also many cases in the Amazon, especially in Tocantins, the state with the highest rates in 2021: 640 cases per 100,000 inhabitants (Goiás, listed next in the ranking, had 340.2 cases per 100,000 inhabitants).
The vaccine against dengue is currently only available in the private market (it costs around R$ 300 Reais) and requires a medical proof attesting the patient has already had contact with the virus. The Butantan Institute has been developing a new vaccine that should promote a more universal immunization and the expectation is that the studies will be concluded by 2024. As a prevention at the moment, the Ministry recommends combating the sources of water accumulation, favorable places for the growth of the disease transmitter mosquito.
Three of the five Brazilian states with the lowest total vaccination coverage are in the Amazon:
Three of the five Brazilian states with the lowest Poliomyelitis vaccine coverage are in the Amazon. See the percentages below:
