Cancer vaccine: the case of the human papillomavirus

Vaccination against cervical cancer (cervical cancer) has proven to be an excellent strategy for controlling the circulation of the types of HPV that cause cancer and genital warts.

The most complete vaccine includes 9 types of HPV. Of these there are seven that can cause cancer, and two types that induce genital warts. It is estimated that it will reduce the incidence of cervical cancer by 90%.

A highly effective vaccine

Since the start of public vaccination campaigns in 2006/7, we estimate that between 100 and 120 million people have been vaccinated. And it turns out that we have excellent safety and efficacy results in all associated pathologies: reduction of infections due to the types of HPV included in vaccines, reduction of persistent infections, reduction of high-grade preneoplastic lesions (the precursor stages cancer) and cervical cancer reduction.

The scientific evidence is sufficiently solid and universal to influence the highest political-health level. The World Health Organization (WHO) declared cervical cancer in 2018 as an eliminable pathology as a public health problem (defined as the reduction in incidence below 4 cases per 100,000 women-years). Shortly after, in May 2020, the World Health Assembly confirmed the proposal and launched the global campaign to eliminate cervical cancer.

This campaign recommends the generalized vaccination of girls before the age of 15, screening with an HPV test for women between 35 and 45 years of age, and access to adequate treatment for the cases identified in the screening.

New information on the role of men in the transmission of the virus and the confirmation of HPV-induced tumor lesions in males have led more than 30 countries to include the vaccination of children in routine vaccination campaigns.

Positive aspects of HPV vaccination

Vaccination against HPV has several positive aspects. Specifically, we highlight five:

  1. The duration of protection is extended. The first cohorts of vaccinated girls currently have 20 years of controlled follow-up. At the moment, no loss of antibodies or the appearance of new infections or lesions has been detected in vaccinated people. The forecast is that vaccination will induce sufficient protection throughout life, without the need for booster doses or revaccinations.

  2. Protection is maintained in all population subgroups investigated. This includes all age groups, immunosuppressed, transplant, HIV / AIDS infected patients, men, pregnant women, individuals already infected with HPV, patients with ongoing HPV lesions, etc.

  3. The safety of HPV vaccines is monitored and confirmed by the approximately 120 million people vaccinated and observed since 2006. All suspected serious side effects have been reviewed up to 9 times by the WHO central vaccine safety bodies and other drug safety regulatory bodies. In no case have toxicities associated with the vaccine or vaccination been confirmed. The latest WHO review explicitly highlighted the high safety of these vaccines.

  4. Protection against cervical cancer was confirmed in 2020. In 2020, unequivocal confirmation was published, with data from Sweden and the Nordic countries, that vaccinating adolescents with the HPV vaccine was able to significantly reduce cases of invasive cervical cancer. And in 2021 it was confirmed by data from the United Kingdom. The conclusions were derived from comparing the incidence of invasive cancer in vaccinated cohorts (systematically vaccinated 12-14 year old girls) with unvaccinated girl cohorts (who reached 12-14 years before the routine introduction of vaccinations).

    This information was added to the data already recorded in previous studies confirming protection against HPV infections, persistent HPV infections, and preneoplastic lesions of the cervix caused by vaccinated HPVs.

  5. Protection against other cancers. Protection against other cancers caused by the types of HPV included in the vaccine will become evident in the coming years, when tumors of the vulva, vagina, anal canal or oral cavity begin to appear, which are tumors that are less frequent and they typically appear at a later age than tumors of the cervix.

A vaccine paradigm that prevents cancer

90% of cases of cervical cancer and other HPV-induced anogenital tumors are preventable by vaccination. HPV vaccines are very effective and efficient, and they have no demonstrable serious side effects after observing more than 120 million people vaccinated over several years.

The WHO launched the global campaign to eliminate cervical cancer in 2020 and recommends widespread vaccination of girls before the age of 15, screening women for HPV at 35 and 45 years of age, and access to appropriate treatments for patients. cases that are identified in the screening.

Covid-19 has practically demonstrated the value of vaccination in resolving viral infections with a high risk of causing serious diseases. HPV vaccination is a paradigm of the possibilities of prevention of a series of potentially lethal cancers and is technically within our reach.

Francesc Xavier Bosch José, Associate Professor of Health Sciences Studies, UOC – Open University of Catalonia Y Subject Company Serrat, Researcher in Health Sciences, UOC – Open University of Catalonia

This article was originally published on The Conversation. read the original.



Reference-www.eleconomista.com.mx

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