HPV: vaccine adherence is lower in boys up to 14 years old – 01/18/2024 – Health

For ten years, the Unified Health System (SUS) has offered children and adolescents the vaccine against HPV (acronym in English for Human Papillomavirus), the main way to prevent against the most common sexually transmitted infection (STI) in the world, associated to the development of most cervical cancers, among other tumors.

Despite the importance of vaccination to combat the disease, data from the Ministry of Health show a decrease in vaccination coverage in general, especially among boys.

Between 2014 and 2023, 70.9% of Brazilian girls received the first dose, while only 54.3% of them were immunized with the second dose. In the case of boys, the rate is even worse: 45.3% received the first dose, and only 27.7% the second.

It is important to highlight that HPV vaccination coverage is not calculated annually, as is the case with other immunization agents, as vaccination is carried out in two doses, the second of which can be applied the following year or at another time.

Therefore, the Ministry of Health’s numbers are calculated by the sum of doses applied since the introduction of the vaccine until the current year.

The vaccine available in the SUS prevents types 6, 11, 16 and 18 of the virus, the most common in the population among the more than 200 types capable of infecting the oral, genital and anal mucosa of men and women.

“The quadrivalent vaccine is available free of charge at more than 38,000 vaccination centers for girls and boys aged 9 to 14, people with immunosuppression, which includes those living with AIDS, transplant recipients and cancer patients aged 9 to 45 can also be immunized.

Last year, the vaccine was also included for victims of sexual abuse aged 9 to 45, men and women”, says Draurio Barreira, director of the Department of HIV/Aids, Tuberculosis, Viral Hepatitis and Sexually Transmitted Infections at the Ministry of Health. .

The vaccine is produced with proteins that are part of the viral capsule, that is, with only a part of the virus that acts to stimulate immunity and the production of antibodies for each type of HPV. Thus, it is an inactive vaccine and, therefore, is not capable of producing diseases.

“It has been proven to have an impact on the prevention of the main high-risk subtypes of infection, especially 16 and 18, which can result in cancer, especially cervical cancer”, says Barreira, who also explains that vaccination against HPV should happen during childhood, because it is important that young people are immunized before starting their sexual life.

Infections caused by types 16 and 18 represent around 70% of cervical cancer cases worldwide.

Research carried out in the United Kingdom and Sweden also showed that the quadrivalent vaccine was able to reduce this type of disease by more than 80%.

The Epidemiological Study on the National Prevalence of HPV Infection (POP-Brazil), carried out by Hospital Moinhos de Ventos, in Rio Grande do Sul, and financed by the Ministry of Health, revealed that subtype 16 is high risk and is the most prevalent in Brazil.

Multivaccination campaign

To try to increase vaccination coverage, the federal government launched a multi-vaccination campaign that includes the vaccine against HPV.

Since the beginning of 2022, a series of efforts have been put into practice to recover high coverage and the vaccination culture in the country. The aim of the Ministry of Health is to restore the population’s confidence in immunizers, prevent the return of eradicated diseases and ensure that Brazil can once again become a global reference on the subject.

“The Ministry of Health’s priority is currently to increase quadrivalent vaccine coverage. The drop in HPV vaccination coverage in recent years represents a concrete threat to the health of millions of young Brazilians and could lead to an increase in cases of infection and cancer avoidable in the future”, says Barreira.

When it comes to the private health network, the vaccine is available to everyone between 9 and 45 years of age.

“In some cases, such as a 50-year-old woman who has just separated and is going to start having relationships with other people, the immunizer can also be recommended”, says the gynecologist, obstetrician and sexologist at Hospital Israelita Albert Einstein, Renata Bonaccorso Lamego .

The private health service also offers the nonavalent version. “It was approved in 2018 by the FDA (regulatory agency linked to the United States department of health), but only arrived in Brazil in March 2023 because of the pandemic. It is indicated for the same audience and has the added protection of more five types of the virus, which increased protection against cervical cancer from 70% to 90%”, explains the doctor.

Most sexually active women have HPV

HPV is a group of viruses that infect the skin and mucous membranes, mainly through sexual contact, whether skin-to-skin or skin-to-mucous contact. Therefore, contagion can occur even with the use of condoms, which makes behavioral changes regarding sexual relations and vaccination very important.

According to the Ministry of Health, around 80% of sexually active women will be infected by one or more types of HPV at some point in their lives. Most of them tend to be transient and are eliminated naturally by the immune system, with regression between six months and two years, after exposure, without causing major problems. In some cases, however, warts appear in the genital region and mouth.

If the disease is not treated properly, it can trigger lesions that are precursors to cancer, especially cervical cancer. Contrary to what many people imagine, HPV can also affect men.

“In this case, the prevalence is estimated to be 30% and the contagion is associated with cancer of the penis, anus, mouth and oropharynx”, says the gynecologist at Einstein.

In women, in addition to cervical cancer, it can be behind cancer of the vulva, vagina, mouth and oropharynx.

In addition to vaccination, women must undergo a Pap smear, a preventive gynecological exam, to identify precursor lesions of cervical cancer. Initially, the exam must be taken annually. After two consecutive exams (one year apart) showing normal results, the preventive test can be done every three years.