HPV vaccine for Cervical Cancer– The Success Story and Controversies

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Human Papillomavirus (HPV) vaccine is the first prophylactic cancer vaccine that has reached the 10-year milestone since it became originally available in 2006. A review conducted by the Royal Women’s hospital in Victoria to coincide with the anniversary reports that infection rates have plummeted up to 90% in areas with high vaccination rates. With over 187 million doses of the vaccine administered across 129 countries, new cases of cervical cancer in women has seemingly halved.

Credit: Wikimedia Commons
Credit: Wikimedia Commons

“All the evidence from Australia shows that the vaccine has virtually eradicated infection among young people and has sharply reduced the incidence of cancers,” Ian Frazer, the co-creator of HPV vaccine, told The Guardian. “That’s a cause for celebration. The evidence is clear that this vaccine is also very safe. We now must make sure it is delivered more widely.”

HPV infection is extremely common in sexually active men and women. Most cases are asymptomatic and the bodies can get rid of it. However, there is a 1% chance of it resulting in cancer. HPV is the cause of more than 70% of all cervical cancer cases besides increasing the risk of penile, anal, vulva, mouth and throat cancers.

Of the 14 strains of HPV associated with cancer, effective vaccines are available against nine: Cervarix (bivalent), Gardasil (quadrivalent) and Gardasil-9. They have been most effective when administered between 9–13 years of age, essentially before one becomes sexually active.

A comparison of available HPV vaccines. Credit: The HPV and Anal cancer Foundation

The above-mentioned meta-data on quadrivalent Gardasil reports maximal reductions of about 90%, 90%, 45%, and 85% for HPV 6/11/16/18 infections, genital warts, low-grade cytological cervical abnormalities, and high-grade histologically proven cervical abnormalities respectively. Another study from the US showed a 64% reduction of HPV infection despite low immunization rates (37% girls and 13% boys aged between 13 and 17). Evidence from the past (WHO 2007, 2011, 2014a, 2014b) has also been similar.

“Observations from over the past 10 years are that the HPV vaccines, if delivered effectively to the majority of 10 to 12 year-old-girls in the developing world from today forward, should lead to the global elimination of new cervical and other HPV-associated cancers by 2050,” Frazer told Brisbane Times.

Do we include it as a mandate and vaccinate boys too?

In the early 2000s, it was widely believed that only girls and young women need the vaccine. The myth was debunked by population studies, which suggested that up to half of adult men in the US, Mexico, and Brazil could be HPV-infected, homo- and heterosexuals alike. The wake-up call to include men in the vaccination programs came about when HPV was established as a major player in increasing number of anal and oral cancers in men.

“Vaccinating homosexual men is crucial”, according to Dr. Anne Szarewski of Cancer Research UK. “If we don’t vaccinate men, then, of course the men who have sex with men get nothing because they cannot benefit from the immunity from women,” she said.

Cervarix has been proven safe in boys of age range 10–18 years and shown to produce anti-HPV antibodies. A study in the US suggested Gardasil was cost-effective in preventing genital warts and anal cancer among gay men. The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) recommends the vaccine for boys in the US and England has launched a pilot-scale vaccination program for homo- and bisexual men.

Credit: Woman 2 Women blog
Credit: Woman 2 Women blog based on ACIP recommendations

The persisting questions and controversy

Despite the proven effectiveness of the vaccine, HPV vaccination has been a subject of opposition even in the developed world. While vaccination rates have plummeted in the US, the vaccine faces legal challenges across Europe. Indian public health experts are still skeptical about its efficacy. They also opine that the diligence required in follow-up procedures may not work well due to lack of awareness and could potentially result in negligence of other women health issues.

The opposition broadly arises on two distinct grounds– moral concern and vaccine safety.

A fairly large number of parents find it disquieting to think about their children being sexually active. Such moral grounds could be boosted further by religious conservatives with sex-centric opinions rather than efficacy or prevention. The major concern seems to be that it may eliminate the fear of infection or genital warts and encourage promiscuity in vaccinated kids. However, data from studies completely contradict this assumption. Vaccinated teens tend to be more aware of sexual health and do not show increased sexual activity than their unvaccinated peers.

Meanwhile, organizations such as The American Cancer Society and FCancer have been listing out the benefits and strongly urging parents and the US government to mandate HPV vaccine for boys and girls before entering 7th grade. On the other hand, countries such as Canada, Ireland, and China have recently joined the list with Australia, Malaysia, and Bhutan. They have expanded the access to HPV vaccine, started awareness campaigns and offer free vaccination, and introduced the vaccine despite difficult drug approval process, respectively.

As for safety, studies published from time-to-time, when questions or debates arise, have all confirmed the safety of the widely administered Gardasil (Eg., 2013, 2015). In response to the protest by Regret in Ireland, The Journal has published a factcheck, which lists these studies on safety and efficacy.

Dr. Suchitra Pandit, former president of the Federation of Obstetric and Gynaecological Societies of India (FOGSI), is for the vaccine. However, she posits, “Rather than speaking for or against the vaccine, we give people the choice and tell them to speak to their children about safe sex — the use of condoms and maintaining genital hygiene. This conversation has started in families and schools.”

The decision to vaccinate or not still hinges on the parents since the vaccine is optional as of now in most countries.

Some facts about Cervical cancer:

  • Human papillomavirus (HPV) is a group of viruses that are extremely common worldwide.
  • You can get HPV by having vaginal, anal, or oral sex with someone who has the virus. It is most commonly spread during vaginal or anal sex. HPV can be passed even when an infected person has no signs or symptoms.
  • There are more than 100 types of HPV, of which at least 13 are cancer-causing (also known as high risk type).
  • HPV is mainly transmitted through sexual contact and most people are infected with HPV shortly after the onset of sexual activity.
  • Cervical cancer is caused by sexually acquired infection with certain types of HPV.
  • Two HPV types (16 and 18) cause 70% of cervical cancers and precancerous cervical lesions.

Sources: Brisbane Times, The Guardian