Brazil: Low vaccination rates after 34 polio-free years are concerning
Polio vaccination rates in Brazil have been falling since 2016, the last time the country surpassed 90 percent vaccination coverage of the target audience. The goal of the National Immunization Program (PNI) is to vaccinate between 90 and 95 percent of children under 5 years old.
However, protection levels have never been so low in Brazil. In 2022, vaccination rates stood at a mere 72 percent, and the preceding year saw an even lower figure of just under 71 percent, as reported by the Ministry of Health. These numbers raise concerns as Brazil recorded its last polio case 34 years ago in 1989. While the disease remains present in other countries, the risk of its resurgence in Brazil is worrisome, potentially leading to the re-circulation of the virus.
Physician Rivia Ferraz, aged 51, was born without any health issues, but unfortunately contracted polio at the age of 9 months due to a lack of vaccination. She explains the circumstances behind not receiving the polio vaccine, stating: "In 1971, we didn't have the country’s public healthcare network SUS. Back then, it wasn't like today, where you can easily take your child to any healthcare facility for vaccination. During a vaccination campaign, I was unwell with fever and vomiting, preventing me from receiving the vaccine. Later, when I had recovered, the vaccine was no longer available."
As a result, she contracted the polio virus, which, similar to COVID-19 today, may not cause symptoms in some children. However, she developed a severe form of the disease, which targeted her spinal cord and resulted in detrimental effects on the motor nerve cells, leading to flaccid paralysis. Ferraz has undergone 14 surgeries to regain limited mobility, and she currently relies on an orthosis to assist her with walking.
According to the Pan American Health Organization (PAHO), most infections of this virus are asymptomatic, but approximately 5 to 10 out of every 100 infected individuals may experience flu-like symptoms. In rare cases, about 1 to 200, the virus can attack the nervous system, resulting in permanent paralysis in the legs or arms. Unfortunately, there is no cure for this condition. The primary effects of the disease include muscle weakness or loss of muscle strength in the affected limb and joint pain.
While extremely uncommon, the virus has the potential to target the brain regions responsible for respiratory function, posing a risk of fatality. According to PAHO, three decades ago, polio caused paralysis in nearly 1,000 children per day across 125 countries worldwide.
WHO
In 1994, Brazil, along with other countries in the Americas, was certified by the World Health Organization (WHO) as polio-free.
The National Immunization Program advises administering the inactivated polio vaccine through injections at 2, 4, and 6 months of age, followed by a booster dose. This vaccine is readily available at all public healthcare centers and can be administered concurrently with other vaccines recommended by the Ministry of Health.
Strategies
The Municipal Health Secretariat in São Paulo has developed a comprehensive plan for this year to mitigate the risk of polio reintroduction and enhance vaccination efforts in the largest city of the country.
Mariana de Souza Araújo, the nurse and coordinator of the Municipal Immunization Program (PMI), highlights that the vaccination timings have been expanded from 7 am to 7 pm, including Saturdays.
In collaboration with the Municipal Secretariat of Education, the PMI has implemented initiatives within schools. Araújo explains, "We offer vaccination services in schools for parents who are unable to bring their children to Basic Healthcare Units."
The coordinator emphasizes that the key to preventing the virus from resurfacing in Brazil is to maintain high vaccination coverage. "In São Paulo, we have achieved coverage close to the target at 80 percent, but it is crucial to vaccinate more children to ensure they receive the complete vaccination cycle and attain full protection."
The PMI coordinator highlights the increased risk to Brazil following a recent polio case confirmation in Loreto, Peru. "As an open-door country, Brazil receives immigrants and refugees, making it essential to maintain our vaccination coverage. We know that countries with low vaccination rates are where polio cases exist. Therefore, our high vaccination coverage serves as the sole preventive measure against the reintroduction of the virus in our country."
The polio virus primarily spreads through person-to-person transmission via the fecal-oral route, although less frequently, it can also be transmitted through contaminated water or food. Once inside the body, the virus replicates in the intestine.
