There are over one hundred different types of human papillomavirus (HPV) that infect the skin or genital mucous membranes. These viruses are very easily transmitted during sexual intercourse, through simple contact with the infected skin or mucous membranes.
Some strains of HPV viruses cause genital warts, precancerous lesions and carcinomas in the genital areas, in the mouth or throat.
HPV viruses are the most frequent cause of sexually transmitted infections, in Switzerland and everywhere in the world. It is estimated that over 70% of sexually active men and women are contaminated during their lifetime.
The risk of HPV virus infection is zero in the absence of sexual relations but increases rapidly with increasing sexual partners. The risk of contagion in Switzerland is maximum between 16 and 25 years, the period during which half of the infections occur.
Most HPV virus infections are asymptomatic, the infected person doesn’t know they are contagious. Certain HPV viruses (such as types 6 and 11) generate genital warts (warts) which can be visible or hidden.
It is estimated that one in 10 people in Switzerland will be affected during their lifetime. Other types of HPV viruses (such as types 16 and 18) can survive for months or years in infected cells, and to cause carcinomas in the genital areas, in the mouth or throat.
Incidence of HPV infections in women
In about 4 out of 5 women, and HPV 16 or 18 virus infection turns into precancerous lesions or a carcinoma, for example at the level of the cervix. These lesions can only be diagnosed through a cytological examination performed by the gynaecologist and possibly other complementary tests.
No medicine allows healing a precancerous lesion or a carcinoma caused by an HPV virus. If lesions are detected in time, laser or surgical treatment can be effective.
Carcinoma of the cervix is , therefore, the consequence of an infection with the HPV virus. In the world, it is the fourth leading cause of cancer in women. In Switzerland, more than 5000 women are confronted each year with a diagnosis of precancerous cervical lesions and have to undergo complementary tests and/or surgery.
Young women are often confronted with this problem, although a carcinoma can appear as early as 20 or 30 years later. Every year in Switzerland, around 250 women have cervical cancer and around 80 dies of it despite a national prevention program and despite all available treatments.
In Switzerland, 70 out of 100 women are infected with an HPV virus. 6 out of 100 women develop precancerous lesions and 1 out of 100 women suffer from cervical cancer.
The extent of HPV infections in men
HPV infections are part of the most common sexually transmitted infections. Half of these concern young people between the ages of 15 and 24. Most of these infections are asymptomatic (the infected person does not know that they are contagious), while some cause the onset of visible or hidden genital warts (warts); in Switzerland, these warts affect about one in ten people.
Some types of HPV viruses (16 and 18) are capable of surviving for months or years in infected cells and causing carcinomas of the mouth or throat.
Vaccine against HPV
The HPV virus vaccine contains a single viral protein, common to several different strains to extend its effectiveness. Its action is supported by an aluminium salt (Gardasil 9) or by a new adjuvant (Cervarix).
The vaccination requires two doses (0, 4-6 months) if it occurs before the 15 ° birthday. Afterwards, 3 doses are needed (0, 1-2, 4-6 months).
Recommendations for teenagers and young women
Vaccination against cervical cancer and other diseases caused by HPV viruses is recommended for all teenagers between 11 and 14 years of age (before their 15th birthday).
The recovery of the basic vaccination is recommended for all young people aged 15 to 19 (before the 20th birthday) who have not yet been vaccinated (3 doses), even if they have already had sexual intercourse.
The vaccine remains active against HPV viruses that have not already been passed on to the person before vaccination.
Vaccination is also indicated individually for some young women aged 20 to 26 ,according to their personal history. The usefulness of vaccination is reduced when the risk of having already been infected is great, for example for women who have had several partners. Therefore, the decision to get vaccinated must be made individually.
Vaccination against HPV viruses is reimbursed by compulsory and exempt from sickness insurance between 11 and 26 years of age, provided that it is carried out as part of a cantonal vaccination program.
For teenagers and young people
Vaccination against genital carcinomas and other diseases caused by HPV viruses is recommended for adolescents between 11 and 14 years of age who wish to protect themselves against a frequent (genital warts) or rare but serious risk (genital, mouth or throat cancers).
Before the 15th birthday 2 doses are sufficient. A recovery of the basic vaccination is recommended for young people aged 15 to 19 (before their 20th birthday) who have not yet been vaccinated and who wish to protect themselves (3 doses are required).
In addition, vaccination is indicated individually for some young people aged 20 to 26, depending on their personal history and risk factors.
The usefulness of vaccination is reduced when the risk of having already been infected is great, for example for young people who have already had several partners. Therefore, the decision to get vaccinated must be made individually.
Vaccination against the HPV virus is reimbursed for all adolescents and young people by compulsory health care insurance and is exempt between the ages of 11 and 26, provided that it is carried out as part of vaccination programs organized by the cantons .
Recommendations for people at increased risk of complications
The risk of carcinoma after an HPV infection increases sharply due to the decrease in immune defences due to medications or diseases.
It is therefore important to ensure that young people between 11 and 26 years of age with a health problem who need or who may need immunosuppressive therapy in the future are adequately vaccinated against HPV viruses.
Examples: rheumatic or autoimmune diseases; HIV infections diseases that may require an organ transplant.
It is never too late to recover one or more vaccinations : do not hesitate to have your vaccination booklet checked by a professional who will be able to advise you. You can start this verification immediately: create a vaccination booklet, enter the information concerning you and register the vaccinations that have been administered to you (or ask DATAVAC to do it for you!): A special software will notify you automatically (red dots) diseases against which you are not yet – or are no longer – protected.
Degree of protection of vaccines against HPV
In Switzerland, it is estimated that vaccination against the HPV virus could theoretically avoid 80-100 new cases of cancer each year in men and around 300 in women.
The two current vaccines offer comparable protection against HPV types 16 and 18. Cervarix® offers slightly better cross-protection, as it covers types of viruses that are not contained in the vaccine. It also provides partial protection against some of the other five types of viruses covered by Gardasil 9®.
All in all, Gardasil 9® offers superior HPV protection compared to Cervarix®: the first vaccine is effective against nine types of HPV, while the second only covers two. However, both vaccines protect against the most common types of HPV and those that are most likely to cause cancer.
For the quadrivalent vaccine, a systematic review of around twenty studies has shown that in the case of vaccination coverage of at least 50%, the prevalence of HPV type 16 and 18 viruses would decrease by 68% after the introduction of vaccination.
A work that has reviewed studies over the past decade describes a possible worldwide reduction of up to 90% for HPV infections of type 6, 11, 16 and 18 and genital warts, up to 45% for cervical cytological lesions low grade and up to 85% for cervical histological lesions at high risk of becoming carcinogenic.
For the nonavalent vaccine (Gardasil 9), worldwide protection is aimed at extending up to 90% against cervical carcinomas and carcinomas of the vulva and vagina associated with HPV viruses, up to 70-85 % against precancerous cervical lesions with a high risk of cancer, and up to 90% against anal carcinomas associated with HPV viruses and genital warts in men and women.
Known side effects of HPV vaccines
Vaccination against HPV viruses is very well tolerated. After 20 years of use and over 270 million doses administered, the only side effects observed are skin reactions at the injection site.
The rumours that vaccines can cause death are unfounded: surveillance authorities in the United States, Europe and Switzerland confirm that there has been no death caused by vaccination against HPV viruses.
For more information on this topic: press release from Swiss medic (in French) and the US CDC website (in English).
According to the results of studies carried out on 73,428 women on all continents between 2008 and 2016, the vaccine does not increase the risk of serious health problems. The researchers found no increased risk of spontaneous abortion among pregnant women after vaccination.