HPV: why vaccine that helps to prevent different types of cancer has little adherence in Brazil?

The definitive cure for any type of cancer is still a dream for Science. But there are already effective means of prevention — one of the important tools for this, the vaccine against the HPV virus, which is available throughout Brazil and contributes to the prevention of at least six types of cancer, has little adherence in the country.

Available in the SUS (Sistema Único de Saúde) for girls since January 2014 and for boys since 2017, the vaccine has been experiencing declines in adherence since the second year of its implementation in the PNI (National Immunization Plan).

Data collected by the Brazilian Group of Gynecological Tumors (EVA) in DataSUS, from the Ministry of Health, indicate that 72% fewer girls and 52% fewer boys were immunized after the first year of vaccination in Brazil (between 2015 and 2021 and 2018 and 2021 , respectively).

Immunization of both sexes is necessary to break the chain of transmission of human papillomavirus (HPV), which is a risk factor for the development of cancer of the penis, vulva, vagina, rectum and head and neck (oropharynx/throat) and, mainly from the cervix.

With access to the HPV vaccine and Pap smear, considered the main preventive test, cervical cancer can be eradicated from the country, as countries like Canada and Australia are on the way.

“Depending on the type of HPV, the virus can represent a low or high risk of progressing to cancer. Today, the vaccine is quadrivalent and protects against the four most frequent types of virus”, explains clinical oncologist Andréa Gadêlha Guimarães, coordinator of advocacy from the Brazilian Group of Gynecological Tumors (EVA) and head physician at the ACCamargo Cancer Center.

In addition to boys and girls, the Ministry of Health expanded the vaccination campaign for immunosuppressed men and women, aged 9 to 45 years, living with HIV/AIDS, transplanted solid organs or bone marrow and cancer patients.

Anyone who is not part of the target audience, but knows that they were not immunized in childhood or adolescence, can receive the vaccine in the private network, depending on a medical evaluation that concludes that the person can benefit.

According to the World Health Organization (WHO), it is estimated that there are 9 to 10 million people infected with this virus in Brazil and that, each year, there are 700,000 new cases of infection.

But if vaccination is important for diseases as serious as cancer, why don’t Brazilian families take their children and adolescents to receive the doses?

Reasons for low adherence to the HPV vaccine

Lack of awareness of the severity of diseases

In Guimarães’ assessment, part of the Brazilian population was losing the perception of the importance of vaccines over time, which worsened during the pandemic.

Mônica Levi, director of SBim (Brazilian Society of Immunizations), adds: “It’s a cliché phrase among doctors, but we say that vaccines are victims of their own success. As diseases are eradicated or become rare, the population loses risk perception. Measles is there to prove that outbreaks can occur thanks to non-adherence”.

“We also have long lines when there are very strong outbreaks — pandemic H1N1 flu, Covid-19… When the situation is balanced, people forget about the disease. high vaccines.”

In the case of vaccination for girls, which began in 2014, doses were given within the school environment, and the first dose had 92% adherence at the time.

“Then, in the second dose, it already dropped a lot, but when it passed to the environment of health centers, the following year, it dropped even more”, says Guimarães, explaining that, for the young public, taking the immunization to them is considered a good strategy to increase adherence, but requires strong logistical planning.

The strategy has already been adopted again in some parts of the country. In the city of Campinas, in the interior of São Paulo, for example, the school Tenista Maria Esther Andion Bueno, was a vaccination point for students between 9 and 14 years old on October 7.

Lack of correlation of HPV with different types of cancer

Many of the vaccines end up being seen as optional by the population, without a careful look at their real benefits.

“It is not known to the general population that this is a vaccine that can help prevent cancers and free of charge”, points out Andréa Gadêlha Guimarães.

Cultural and religious factors

“Some people, especially those with more conservative religious principles, believe that giving the vaccine can be a stimulus to early sexual activity. It is a big mistake. Although HPV is a sexually transmitted virus, this correlation does not exist. Hepatitis B also can be transmitted sexually and is given in the maternity ward”, explains the oncologist.

A study published in Jama Internal Medicine in 2015 corroborates this. After analyzing data from thousands of young women within the recommended age range for immunization, the researchers concluded that the HPV vaccine does not lead teenagers to adopt early or risky sexual behaviors, nor does it increase rates of sexually transmitted diseases.

“The recommendation to vaccinate children and young people is made precisely because, at this age, they have not yet been exposed to the virus, which makes the ability to create antibodies greater. [depois do início da vida sexual]can bring a smaller benefit”, points out Mônica Levi.

misinformation

“Supposed serious adverse events about vaccines, not only the one that fights HPV, are spread frequently. But the information is false. The adverse effects are mild, related to the place of application, such as redness and local pain”, says Guimarães.

The effects of this are a confused and distrustful population in vaccines. “For boys, only 37% of the target population took two doses. It’s very little, a waste of investment in public health. For a mother of a baby who gets fleas behind her ear because of fake news, for example, it’s It is easier for her to take the risk of the disease, which she thinks will not reach her child, than to risk a supposed very serious side effect right after vaccination. The anti-vaccine movement has become more organized post-pandemic and has been effective in causing hesitation .”

The experts explain that the vaccine is made with an inactivated virus, that is, it does not contain the DNA of the virus, only proteins of the viral capsid (virus envelope), which is not capable of producing the disease in the human body.

“The surveillance of this vaccine is one of the best that has ever been done. We have a media polluted with false information that makes people afraid, and teenagers, who do not necessarily understand the importance, are also the target of this fake news”, says the director of SBIm .

In her assessment, the communication campaigns of the Ministry of Health are currently terrible. “We have already been a world example of how to communicate and now we are as bad as other places with bad vaccine coverage. The Ministry of Health itself recognizes the need to fight fake news.”

logistical difficulties

There are also issues related to strategies, such as health posts open only during business hours, and fathers, mothers and other family members unable to take the child or young person on account of work. “This is already being understood by the PNI as a barrier, and it is easier to get around. Some places have already started to offer schedules on Saturdays and Sundays, for example”, says Levi.

In addition, the specialist assesses that the Ministry of Health’s data supply leaves something to be desired, which can hinder campaigns and the updating of immunized numbers.

“Some health posts have poor internet, a manual or digitalized system, but old, in addition to human errors. In the pandemic, the press consortium that provided data was more effective in communicating updates to the population than the Ministry itself. of health.”

This text was originally published here.