Rubella and polio: eliminated diseases threaten Brazil again

Publicação: 11 de September de 2019

In June, the PAHO issued an epidemiological alert regarding the risk of importation and reintroduction of rubella virus in the Region of the Americas

Argentina and Chile reported cases of rubella in 2019. Vaccination should be intensified

The return of measles showed that any eliminated or controlled disease can come back. “Its reappearance is an example of vulnerability to any non-eradicated disease, including rubella and polio.” The warning comes from the president of the Brazilian Society of Immunizations (SBIm), Dr. Juarez Cunha. For him, the return of these diseases is a very big setback in terms of public health and collective health. These diseases can have very serious consequences: polio can lead to childhood paralysis and rubella can lead to serious birth defects such as deafness, heart disease and neurological problems.

The expert’s warning is justified. At the end of June, the Pan American Health Organization / World Health Organization (PAHO/WHO) issued an epidemiological alert regarding the risk of importation and reintroduction of rubella virus in the Region of the Americas. The Organization has urged Member States to strengthen surveillance and intensify immunization activities to achieve coverage levels above 95% in all children under the age of 5 and also to respond rapidly to imported cases. According to the document, the last cases of rubella in Brazil were reported in 2009. However, in 2019, Argentina and Chile had confirmed cases of the disease.

Dr. Juarez Cunha explains that the warning aims to draw the attention of people who coordinate immunization programs and governments across America to a disease that is eliminated but is likely to return. “It is a warning to take the necessary measures to increase vaccination coverage, the best and the only way to maintain this situation of elimination of the disease throughout the continent”, he adds while adding that all Brazilian municipalities are considered places of risk for these diseases. “Vaccination coverage has been declining in recent years, and since 2018, the Ministry of Health has begun to draw the attention of the scientific community and the population to the risks we are taking.

The concern with polio occurs because there has been records of the disease in Venezuela and the circulation of the virus in 23 countries in the last three years. Wild poliovirus cases have declined by more than 99% since 1988, when 350 cases were estimated in more than 125 endemic countries. In 2018, 29 cases were notified and in 2017, 22 cases. According to the WHO, polio eradication requires high vaccination coverage worldwide to block the transmission of the extremely contagious virus. Unfortunately, some children remain without access to adequate doses for a variety of reasons, including lack of infrastructure, remote locations, migration, conflict, insecurity and resistance to vaccination.

In Brazil, there have been no cases of virus circulation since 1990, a situation that is threatened by the decrease in vaccination coverage throughout the country. Last year, the Ministry of Health issued a warning for low vaccination: 312 cities did not vaccinate even half of the children under 1 year in 2017. Until polio eradication, 26,827 cases were registered between 1968 and 1989. The 70s recorded most cases. There was a peek in 1975 with 3,596 records. In 1979 several cases were also reported, 2,564. According to Datasus, polio vaccines have not reached the vaccination goals in Brazil since 2011. In 2016, municipalities had lower vaccination rates: only 43.1% of the cities reached the goal.

According to the president of the SBIm, the way to deal with outbreaks we have seen in neighboring countries is to increase our immunization coverage. “All diseases that have occurred are immunopreventable, and if we have adequate vaccine coverage, we will prevent the return of diseases such as rubella and polio. The return of eliminated or controlled diseases is not the fault of people or neighboring countries, they occur because our coverage is not adequate. We must remember that we no longer have these diseases thanks to vaccination, so not vaccinating means a high risk of them coming back”, says Dr. Juarez Cunha.

Vaccines

There are two types of polio vaccine in Brazil, an oral and an injectable. The Oral Polio Vaccine (OPV) is a bivalent attenuated oral vaccine, which is composed of living but “weakened” poliovirus 1 and 3. The Inactivated Polio Vaccine (IPV), being inactivated, cannot cause the disease. It is a trivalent and injectable vaccine made up of polio virus particles types 1, 2 and 3. Immunization should start at the age of 2 months, with two more doses at 4 and 6 months, and boosters between 15 and 18 months and between 4 and 5 years of age.

The MMR vaccine, which protects against measles, mumps and rubella is also critical, and is an attenuated vaccine containing “weakened” live measles, rubella and mumps viruses. To be considered protected, every individual must have taken two doses in their lifetime, at least one month apart, after 12 months of age.

For children, the Brazilian Society of Pediatrics (SBP) and SBIm routinely recommend two doses: one at 12 months and the other between 15 months and 24 months, together with the varicella vaccine, and can be applied as separate vaccines (MMR and varicella) or combined (tetra viral: MMR-V). For older children, adolescents and adults not yet vaccinated or without proven doses, two doses with an interval of one to two months are recommended. In the National Immunization Program (PNI) routine for childhood vaccination, the first dose is given at 12 months of age; and at 15 months (when using the varicella vaccine [tetra viral: MMR-V]).

Individuals up to 29 years (two doses, with a minimum interval of 30 days) and individuals between 30 and 49 years (one dose) can also be vaccinated for free. Vaccines are available free of charge at public health clinics and are highly effective at prevention. Vaccines are safe and effective.