Should vaccination be generalized? ⋅ Inserm, Science for health

In France, at the end of 2021, only 45.8% of 15-year-old girls and barely 6% of boys of the same age had received at least one dose of the vaccine which protects against infections with the human papillomavirus (HPV), a virus responsible for cancer. This vaccination coverage is among the lowest in industrialized countries, far from the objectives set by the National Sexual Health Strategy and the Cancer Plan: 60% among adolescent girls aged 11 to 19 in 2023 and 80% by 2030. In this context, the President of the Republic has just announced the launch, as of the next school year, of a generalized vaccination campaign, for all pupils in class of 5e.

The human papillomavirus (HPV) is the main risk factor for cancer of the cervix, but it is also the cause of cancers of the ENT sphere, anus, vulva, vagina and penis. . But there is a vaccine that can prevent it. This vaccination has been recommended for young girls aged 11 to 14 (with catch-up up to 19 years) since 2007, and for boys of the same age since 1is January 2021. It is also recommended for men having homosexual relations and immunocompromised people. Is it legitimate to include the whole population? What are the risks ? And what do we know about the social factors of vaccine hesitancy in France? Here, three experts combine these issues of public policy, medical practice and society.

According to an article published in Inserm magazine n°46 (March 2020), updated in March 2023

Élisabeth Bouvet: generalizing vaccination also means making it easier to accept

The High Authority for Health (HAS) and its technical commission for vaccinations recommend the vaccination of all adolescents from the age of 11 against the human papillomavirus. Several types of HPV, very common in the population, are responsible for warts (condyloma) and lesions, a minority of which cause 6,000 new cases of cancer per year. HPV is the leading cause of uterine cancer, with approximately 3,000 cases per year, which explains why young girls were targeted as a priority. However, HPV causes approximately 100 penile cancers, 1,350 anal cancers, including 350 in men, and 1,540 head and neck cancers, including 1,180 in men. In addition, men and women suffer from 100,000 new benign tumors per year, leading to numerous medical procedures. There is therefore no reason to target only women for individual prevention, nor to place the entire burden of the fight against the transmission of the virus on them. On the contrary, since HPV is sexually transmitted, its circulation is much better restricted if both partners in a heterosexual or homosexual relationship are vaccinated. Generalizing vaccination also facilitates its acceptability: it is much simpler for doctors to systematically offer this vaccine to all adolescents during a wave of booster shots. This standardization has positive effects in all the countries where it is practiced, including the United States. In addition, the HAS public consultation revealed a request from doctors and associations in this regard.

Consequently, the HAS has recommended since December 2019 the generalization of anti-HPV vaccination to all adolescents aged 11 to 14, with possible catch-up for all young people aged 15 to 19. Although this recommendation has been translated into the vaccination schedule, its implementation is still timid: vaccination coverage is progressing, especially among girls, but it remains insufficient. Also, carrying out vaccination campaigns in schools is essential to significantly increase the vaccination of young people of both sexes.

Élisabeth Bouvet is president of the technical commission for vaccinations at the Haute Autorité de santé, in Saint-Denis.

Michel Cogné: a benefit/risk indisputably in favor of generalization

While prevalence of HPV infection continues to decline in countries with the same development as ours, it is stagnating in France due to a very low vaccination rate. All young girls are far from being vaccinated, and all young men should be too! Indeed, about a quarter of cancers induced by this virus concern men. Those who have more sexual partners are most at risk. This is particularly the case for many men with homosexual practices, in whom the frequency of anal cancers is also higher. But in reality, everyone is affected by the papillomavirus and there is no justification for limiting vaccination to a single sex or to a given type of sexuality. To extend the vaccination recommendation only to homosexuals, as was done in 2017, would be to refrain from vaccinating before the age of first sexual intercourse and to forget that heterosexual men are also targets and vectors of the virus. . To limit the spread, everyone must be vaccinated! The United Kingdom has understood this: 84% of boys and girls are vaccinated there. Doctors and pharmacists must also be well informed to relay accurate information, and recommend early vaccination (while cutting short the misconception that the vaccine against HPV would become useless as soon as one started his sexuality). Concerning misinformation about vaccines on the Internet is hampering public health: ideological anti-vaccine groups are trying to hide the enormous benefits of vaccination behind its rare adverse effects. Like any active drug, some vaccines may have some side effects. Any stimulation of immunity, by a virus or a vaccine, can sometimes induce immunoallergic reactions. But the risks are minor in view of the expected benefit. To take an automotive comparison, we will remember that the seat belt, even if it is sometimes at the cost of bruising or even a broken collarbone, can above all prevent a motorist from dying while crossing his windshield! Coming back to the HPV vaccine, the benefit/risk calculation is unquestionably in favor of its generalization, in particular with the nine-valent formula, which protects against the most dangerous types of the virus.

Michel Cogné is an immunologist in the Microenvironment laboratory and lymphocytes B : immunopathology cell differentiation and cancer (Mobidic, unit 1236 Inserm) reindeer.

Fadia Dib: the involvement of GPs, a lever to overcome vaccine hesitation

To understand the determinants of hesitation vis-à-vis the HPV vaccine, a telephone survey was carried out in metropolitan France in April 2021, with a representative sample of 1,102 mothers of girls aged 11 to 14. . The factors most strongly associated with the absence of anti-HPV vaccination of these young girls were related to their age, real or “perceived” by their mother. On the one hand, the younger they were, the less chance they had of having been vaccinated: in this sample, the probability of being vaccinated at age 11 was 83% lower than that of being vaccinated at age 14. On the other hand, regardless of their age, the fact that mothers thought they were too young to be vaccinated against a sexually transmitted infection reduced their chance of having received the vaccine by 84%. This study also pointed to two factors positively associated with vaccination: when a mother thinks that doctors see vaccination as a good idea, her daughter is 5 times more likely to be vaccinated than in the opposite case. And the fact that the mothers have asked their doctor about this subject multiplies by 3 the probability that their daughter will receive the vaccine. Finally, this work led to the identification of significant misunderstandings of the mothers questioned regarding HPV infection. For example, only 20% of them considered – rightly – that HPV infections can cause ENT cancers, and less than half knew that having sex at a young age increases the risk of contracting an HPV infection. .

Several recommendations can be formulated in the light of these results. Among the levers to be activated, lowering the eligibility threshold for anti-HPV vaccination at the age of 9 would make it possible to dissociate it from sexuality, and thus facilitate its acceptance. This question of the threshold age is not new: in 2012, faced with very insufficient vaccination coverage among 14-year-old girls, the age initially targeted in 2007, the High Council for Public Health took up its own and had issued an opinion in favor of extending this vaccination to 11–14 year olds. The interest of a further lowering of the targeted age is corroborated by the scientific literature and advanced by American learned societies. At the same time, the other actionable levers are the strengthening of the training and involvement of general practitioners in the recommendation to vaccinate against HPV, as well as the realization of communication campaigns intended for the general public, targeting not only parents but also teens.

Fadia Dib is a public health physician at the Directorate General for Health and a former doctoral student at the Pierre-Louis Institute of Epidemiology and Public Health (Iplesp, Inserm unit 1136) in Paris.

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