HPV Vaccine Protects Men and Women from 4 Deadly Cancers— Including Cervical Cancer— But Misinformation is Harming Its Acceptance

Misinformation about the safety, efficacy and benefits of the potent vaccine against the deadly Human Papilloma Virus (HPV) that causes cancer in men and women, and parental refusal to give consent, are impeding its uptake in the ongoing national drive targeting school-age adolescents.

HPV is one of the most common sexually transmitted infections in the world and it spreads in heterosexual and monogamous relationships— even if someone waits until they get married to have sex, and only have it with one sexual partner, infection with the virus can still occur if the partner has been exposed— and even when condoms are used. It is so common that nearly everyone who is sexually active will be infected at least once in their lifetime. By age 50, at least four out of every five women will have been infected with HPV at one point in their lifetime.

In 2017, the World Health Organisation estimated that worldwide prevalence of HPV in women was 11.7 percent. Latin America and the Caribbean had a prevalence of 16.1 percent, the second highest prevalence for women after Sub-Saharan Africa (24 percent).

Prevalence of HPV in men is high in all regions of the world and peaks at a slightly higher age than in women. Prevalence of any HPV type on the penis in particular was 18.7 percent; on the scrotum, percent; and on the perinium, 7.9 percent. Men who have at least three lifetime partners have 4.5 times the odds of contracting the virus.

While most infections are symptomless and subside on their own— 9 out of 10 HPV infections go away on their own in one to two years— if one is infected with certain high risk types of HPV (HPV-16 and HPV-18) repeatedly, it can worsen and develop into cancer overtime. It is estimated that one in every 100 women in developing countries will have cervical cancer before the age of 75.

Kenya has a population of 16.2 million women aged 15-years and older who are at risk of developing cervical cancer and current estimates indicate that every year, 5236 women are diagnosed with cervical cancer and 3211 die from the disease.

It takes between 10 and 20 years, or longer, from the time one is infected to develop overt cancer, and, the best time to vaccinate your daughter (and son) is between 9 and 12-years before they become sexually active— the risk of HPV infection is not only highest immediately after sexual debut, but biological response (antibody levels) following vaccination is greater in children aged 11 to 12 years compared to those older than 16-years. ?

Lifelong Protection

The HPV vaccine provides lifelong protection, and girls and boys aged 13 to 26 and 13 to 21 years, respectively, should get the catch up vaccine if they did not receive it earlier. Previous sexual intercourse is not a reason not to vaccinate someone.

While studies show that it’s safe and effective, as a precaution, adolescents should always be sitting, or lying down, during administration and be observed for 15 minutes to avoid serious injury related to a rare syncopal (fainting) episode.

The HPV vaccine prevents girls and boys from several cancers— cancer of the cervix, vagina and vulva in women; cancer of the penis in men; and cancers of the anus, mouth or throat in men and women.

For best protection, one requires three shots over the course of six months, the second and third injections given one or two months, and 6 months after the first shot, respectively.

?Natural immunity

With some viruses, being infected once can protect against future exposure and reinfection. However, studies have shown that while most individuals infected with HPV are able to clear, or control their infection, there is no evidence of lifelong protection from natural immunity after a first infection for two reasons:

First, compared to prophylactic HPV vaccination which provides lifelong protection, the antibody levels from infection are considerably lower than those observed following vaccination. Second, although infection with one type of HPV— there are over 100 subtypes— may provide some protection against that one particular type, it will not provide protection against other HPV types. ?

?Herd immunity

In Australia and Nordic countries with national HPV vaccination rates exceeding 80 per cent and targeting adolescent girls in schools, vaccinated women have remained cancer-free for 15-years with a significant reduction in early markers of HPV infection such as genital warts in young men and women (photo of genital warts in a woman below), cervical precancerous lesions and cervical dysplasia.

HPV also causes cancer in men— penile cancer, anal cancer, and a subset of head and neck cancers, specifically, squamous cell carcinoma of the oropharynx at the base of tongue and the tonsils— and to achieve herd immunity, it’s important to vaccinate both boys and girls. Research from Australia has demonstrated that herd immunity does not occur when only young women are immunised.

Routine screening

Routine screening for cancer of the cervix should begin at age 21 years, even if the woman has had the HPV vaccine. Women aged 21 to 29 years should be screened with the Pap smear test every three years. Women aged 30 to 65 years have the option of either having a Pap test every three years, or having a Pap test plus an HPV test every five years. Screening more frequently than this does not provide more protection, and routine screening is not recommended after the age of 65 years, given a history of normal screenings.

Screening is not recommended for women who have had a hysterectomy with removal of the cervix and who do not have a history of high-grade precancerous lesions.

In most low-income countries, access to screening and diagnosis services is limited and awareness of the need for regular Pap smears is also low leading to many women presenting with advanced cervical carcinoma. We also don’t have screening for the cancers that HPV causes in males. As such, preventing these cancers in men and women through primary prevention with HPV vaccination remains the best strategy.

Studies show that combining cervical cancer screening and the HPV vaccine could prevent as many as 93 per cent of all cervical cancers.

The real benefit is that with one vaccine, we can prevent four different cancers and save lives.

Subiri Obwogo is a medical doctor, specialist in public health medicine and independent consultant in health policy and systems strengthening. He’s also the author of two books and several publications.