Papilloma virus: what the science says

Papilloma virus: what the science says
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Human papilloma virus (Human papilloma Virus) is the most common of sexually transmitted infections, so much so that it is estimated that over 80% of sexually active women become infected later in life. The risk of contracting the infection begins with the first sexual contact and can last for a lifetime.

HPV infection can be transient (the virus is eliminated by our immune system), asymptomatic (those who are infected do not notice anything) and usually heals spontaneously (resolution within 1-2 years of infection). In 10% of cases, however papilloma virus infection becomes persistent and in these cases it could cause cellular degeneration and tumor progression.

In particular, two strains of the HPV virus (16 and 18) alone are responsible for 70% of cervical cancer cases. It is therefore considered the sworn enemy of women. “But not even men can rest assured in the event of a close encounter with this pathogen. For this reason, the new vaccination plan also extends anti-HPV vaccination to males, as an individual prevention measure, but also to indirectly reduce the spread of the virus from men to women "he explains Pierluigi Lopalco, professor of hygiene and preventive medicine at the University of Pisa, who we asked to help us clarify.

In this article

  • papilloma virus
  • HPV and cancer
  • vaccination
  • vaccinate females
  • vaccinate males
  • at what age to get vaccinated

What is papilloma virus

The human papilloma virus is a very common virus, so much so that, as reported by the National Institute of Health, about 80% of individuals are infected in the course of life. "It is transmitted above all through sexual intercourse, or through very close inter-human contacts: to contract the infection, that is, a simple skin contact in the genital area»Explains Prof. Lopalco. And then he specifies: "in reality when we talk about Papilloma virus we refer to a class of viruses: there are about 100 types, some are harmless, while others can cause annoying but benign diseases, such as skin warts or the most annoying warts on the genitals (warts), the so-called cockscombs, which can affect both women and men. Others, on the other hand, are carcinogenic ».

Read also: Papilloma virus: symptoms, transmission and vaccination. Everything you need to know

Human papilloma virus and cancer

There are more than a hundred strains of human papilloma virus (HPV). Those capable of infecting the genital tract are more than 40, but only a few are cancerous and are called "high-risk serotypes". Those defined as "low-risk serotypes", on the other hand, are the cause of condylomas, warts that appear in the genital or anal area, substantially benign even if highly contagious. 

It is known for example that strains 6 and 11 are responsible for 90% of warts, while 16 and 18, as recalled by the Del Paesena Association for Cancer Research, are alone responsible for the About 70% of cervical cancer cases. Papilloma viruses can also cause anogenital and oropharynx tumors in both women and men.

According to estimates by the US National Institutes of Health, the HPV virus is responsible for:

  • almost all cancers of the uterine cervix;
  • 95% of tumors of the anus (mostly due to HPV 16);
  • 70% of cancers of the oropharynx (in which viral transmission occurs through oral sex);
  • 75% of cancers of the vagina;
  • 70% of cancers of the vulva;
  • 60% of penile cancers.

However, these data also vary depending on the country being examined. In Del Paese, for example, the Istituto Superiore di Sanità estimates that HPV is responsible for 26% of oropharyngeal cancers, against 70% in the US.

According to the World Health Organization (WHO), which has supported the introduction of vaccination since the beginning, 5% of all cancer cases worldwide are associated with HPV infection.


Read also: Human papilloma virus: 32 questions and answers to know everything about HPV

What vaccines are available

"Starting from the seventies, thanks to classification and epidemiological studies we were able to identify which cancer subtypes were more frequent and so the first vaccines were developed" explains Lopalco. Thus, starting in 2006, the very first vaccine against papilloma virus was marketed. "The first we had available is the Cervarix: a bivalent vaccine against two viral strains (16 and 18) which alone are the cause of more than 70% of cervical cancers. It is therefore a vaccine designed to prevent this type of cancer which is the most frequent and most mortal of those caused by HPV »says Lopalco.

A 4-strain vaccine, Gardasil, which, in addition to acting against the viral strains responsible for cervical cancer, also acts against two strains (types 6 and 11) that are not cancerous but much more frequent and responsible for genital warts. "This was therefore the first vaccine also offered to the male population."

A third vaccine has also become available since 2022, he said nonavalent, which protects against 5 other subtypes (31-33-45-52-58) capable of inducing cancer. A vaccine that, as reported by the New England Journal of Medicine, is not only a milestone in uterine cancer prevention, but also extends protection to other HPV subtypes.

Read also: Papillomavirus: why vaccination is important

Why vaccinate females

As mentioned above, it is estimated that up to 80% of sexually active women become infected with one or more types of human papilloma virus and even more than 50% become infected with a "high risk" serotype. According to estimates by the World Health Organization, more than 500.000 women are diagnosed with cervical cancer each year, and 300.000 women die of this tumor. Cervical cancer is among the more frequent tumors in women and is caused by an HPV infection in nearly 100% of cases. Avoiding HPV infection prevents possible cancerous degeneration. 

In our country, papilloma virus infection is frequent, both in the female and male population. In Del Paese, in fact, they are diagnosed approximately 3.500 new cases of cervical cancer each year and over 1.500 women die from this cancer. "The vaccine also protects against chronic infections which - Lopalco points out - even if they do not develop into cancer, negatively affect the psychological and sexual health of women".

Through vaccination against HPV it is therefore possible to stop at the origin the chain from infection to cancer: generally from the infection to the onset of precancerous lesions it can pass 5 years, while the latency for the onset of cervical cancer can be decades.

In addition, around 130.000 new cases of genital warts are recorded every year in Del Paese (warts) in females and 80.000 in males, diseases also sustained by some strains of Papilloma virus.

Read also: Hpv and pregnancy. My experience

Why vaccinate males

The primary target of the anti-HPV vaccine is the female population because in fact the vaccine was born as a weapon to counteract the most frequent tumor disease with the highest impact worldwide, cervical cancer, caused by this pathogen. . “Over time, however, it became clear that the benefits of vaccination could be extended to the entire population. With the vaccine, in fact, not only males protect themselves from condylomytosis, but also from cancer of the male genitals, penis, anus and carcinoma of the oropharynx ». These tumors in Europe affect an average of 15.500 men each year, of which about 2000 in our country alone. If we look at the data, we also find that the mouth cancer it affects men more than women.

If all this has to do with the direct and individual benefits that the male would derive from the HPV vaccination, the pediatrician Rosario Cavallo, national referent for vaccinations of the Cultural Association of Pediatricians, underlines i social benefits which derive fromextend vaccination to the male population. In practice it is considered the best containment strategy for this virus. "In fact, we explain to parents that vaccinating male children helps to avoid some male cancers - which are exceptionally rare - and prevents warts - which are relatively frequent and very annoying but do not endanger life - but it is fundamental in terms of solidarity. for public health. Because the vaccination of the male population has an impact on the protection of female health ».

«In fact, in several parts of the world it has been found that by vaccinating both males and females the circulation of HPV is reduced reducing the chain of infections »explains Lopalco, thus underlining the finding of a good effect of herd immunity. In other words, «simply by vaccinating girls, a lower circulation of the virus has been observed even among unvaccinated women. Because the vaccinated woman cannot infect the man who in turn does not infect the unvaccinated woman. And considering that the male is the main infector of sexually transmitted diseases, by vaccinating the males the herd effect becomes much more evident ».

Currently, according to the World Health Organization, male adolescents should also be vaccinated, as envisaged in Del Paese by the National Vaccine Prevention Plan 2022-2022. The FDA, the American Medicines Agency, deems it appropriate to vaccinate males aged 13 to 21, extending the maximum vaccination age to 26 for homosexual males.

Read also: HPV vaccination: why does it make sense to do it in males too?

At what age to get vaccinated

Vaccines are suitable for boys and girls starting from 9 years and there is no upper age limit, so if you want you can do it even at 40 years old. "But we know that the earlier the vaccination, the more effective it is," recalls Lopalco. In fact, these vaccines are most effective in the so-called "naive subjects": that is, people not yet infected with the HPV virus, which is usually acquired immediately after the start of sexual activity. This is why vaccination is recommended before puberty, before the start of an active sex life.

Since 2008 in Del Paese, vaccination was paid for by the health system for 12-year-old girls (although to tell the truth some regions had extended the active offer of vaccination to other age groups). Now with the new National Vaccine Prevention Plan 2022-2022, free vaccination during the twelfth year of age is also provided for males. In Del Paese, most regions also provide for the facilitated payment for other age groups.

The vaccination schedule provides for the administration of:

  • 2 doses of vaccine 6 months apart in adolescents up to 13/14 years;
  • 3 doses with a distance of 1-2 months (the second dose) and 6 months (the third) from the first dose for older children.
Read also: Vaccinations for adolescence provided for by the Vaccine Prevention Plan

In summary Pierluigi Lopalco recalls that HPV vaccines:

  • They are effective: according to clinical studies, the efficacy against viral strains included in vaccines is extremely high, leading to a reduction in the lesions.


  • They are safe. Over 180 million doses (of the bivalent and 4-strain vaccine) have been distributed so far and data on their safety are based on these doses. According to the World Health Organization these vaccines have an excellent safety profile.


  • Effetti collateraliThe main one is pain at the injection site, which can last for 24 hours. Some teenagers have reported feeling paralyzed, sore, arm after vaccination, which has contributed to some anxiety about this vaccine. In reality, both the documents of the European Medicines Agency and those of the Global Commission for Vaccine Safety of the World Health Organization exclude cause-and-effect relationships between any disorders such as chronic pain, autonomic syndromes and motor problems and anti-vaccination. HPV.

Questions and answers

Do I still have to get a Pap test after the vaccine?

Yes, cervical cancer screening (Pap smears) must also be done by vaccinated women. The papilloma virus vaccine is the most effective weapon to prevent most cases of cervical cancer, but not all. Screening is therefore also necessary for vaccinated women. According to what is reported by the Del Paesena Association for Cancer Research, it is estimated that currently in Del Paese the screening program allows to diagnose approximately 130.000 cases of precancerous lesions every year.

Is a condom always necessary?

Absolutely yes. The condom must continue to be used even after the HPV vaccination to protect against sexually transmitted diseases.  

Sources used:

  • consultancy by Prof. Pierluigi Lopalco, professor of hygiene and preventive medicine at the University of Pisa;
  • Del Paesena Association for Cancer Research, Do We Really Need the HPV Vaccine ?;
  • National Institute of Health, HPV Infection and Cervicocarcinoma;
  • National Institutes of Health, HPV and Cancer;
  • World Health Organization, Human Papillomavirus (HPV) and cervical cancer.

  • vaccinations for children
  • papilloma virus
  • hpv vaccination
  • hpv vaccine
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