The Virus Has Over 200 Types, and the Vaccine Protects Against the Main Ones That Cause Several Cancers
By: José Carlos de Morais
Photos: Renato Rodrigues/Butantan Communication
Published on: 09/04/2023
Understanding the Importance of the HPV Vaccine
Is it worth getting the HPV vaccine if you’ve already been infected by the virus? Absolutely. Even after an infection, the vaccine can offer significant benefits to both women and men. There are over 200 types of the Human Papillomavirus (HPV), and the vaccine targets four critical types—6, 11, 16, and 18—that are primarily responsible for causing cancers of the cervix, anus, vulva, vagina, penis, and oropharynx. According to the Ministry of Health, 80% of sexually active individuals will contract one or more types of HPV during their lives. However, a person infected with one subtype can still protect themselves against other subtypes by getting vaccinated.
Reducing Recurrence and Providing Broad Protection
Research has shown that the HPV vaccine can reduce the likelihood of recurrence (return of the infection) by up to 80% in individuals who have previously had HPV-related lesions. This finding comes from a review by the Brazilian Federation of Gynecology and Obstetrics Associations (Febrasgo).
Additionally, 99.6% of sexually active women up to 45 years old can benefit from the vaccine, as many test negative for the virus or are positive for only one subtype. This broad protection is crucial in preventing new infections and the development of serious health issues.
The Limitations of Natural Immunity
Natural HPV infection does not generate sufficient immunity to prevent new infections. The quantity of antibodies produced is typically low and does not last long. Studies from Johns Hopkins University and the University of Washington revealed that antibody levels induced by HPV-16 infection were 50 to 60 times lower than those achieved after vaccination.
Safety and Effectiveness of the Vaccine
Both HPV vaccines available in Brazil—the quadrivalent and nonavalent—are proven to be safe, with no severe adverse reactions recorded in any age group. The vaccine is recommended for individuals aged 9 to 45, both men and women. It not only protects against the disease but also helps prevent the ongoing transmission of the virus.
The benefits of the vaccine are well-documented: a comprehensive review of 65 studies conducted in 14 countries, involving 60 million people, showed an 83% reduction in cases of HPV types 16 and 18 (responsible for 70% of cervical cancer cases), a 67% reduction in genital warts, and a 51% reduction in pre-cancerous lesions in girls aged 15 to 19.
Why the Public Health System (SUS) Prioritizes Children
In Brazil’s Unified Health System (SUS), the HPV vaccine is administered to boys and girls aged 9 to 14. The goal is to protect individuals before they become sexually active, which is the primary mode of HPV transmission. Vaccination is more effective at this age because children and adolescents produce higher quantities of antibodies compared to adults. Therefore, promoting vaccination in this age group is crucial.
However, this does not mean that older individuals, who missed the opportunity to be vaccinated in childhood, cannot benefit from immunization. Scientific data supports the benefits of vaccination at any age. Currently, HPV vaccines for adults are available only through the private sector, with an exception for immunosuppressed individuals, transplant recipients, or cancer patients up to 45 years old, who can receive the vaccine through the SUS.
For more information, consult healthcare providers or visit the Butantan Institute’s website.
Report: José Carlos de Morais
Photos: Renato Rodrigues/Butantan Communication
Read the original article here
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