One year ago I wrote a column on the ethics of paediatricians discharging vaccine-hesitant parents from their practices. Since that time there have been some interesting developments on the vaccine ethics front. Most notably we have experienced an international measles outbreak, which originated at Disneyland in California and was most likely caused by pockets of unvaccinated children. We also had some local controversy when the Toronto Star published a story titled, “A wonder drug’s dark side,” which focused on anecdotes of several young women who had become sick after receiving the HPV vaccine Gardasil. The story sparked very strong reactions on both sides of the vaccine debate. Although much has been written about the ethics of vaccines and the morality of “anti-vaxxer” parents, especially since the measles outbreak hit the news, there are some unique aspects of the HPV vaccine that make it a bit different than other types of vaccines.
Suppose scientists discovered that a there is a virus that causes 70 per cent of lung cancers and a vaccine was developed that could prevent someone from contracting this virus, thus greatly reducing one’s chance of developing lung cancer. Would you get the vaccine? Seems like an easy decision to me. Now suppose that the vaccine had to be administered during early adolescence in order to be effective. There is probably a bit more discomfort now, but my guess is most of you probably would want your children vaccinated. Now suppose that the virus is one that is transmitted through sexual contact. Did this cause you to squirm a bit? This is precisely the situation with the HPV vaccine. A 2009 survey of parents in the United States found that while at least 80% of them thought vaccines should be mandatory for MMR, varicella, tetanus/diphtheria, and Hepatitis B, only 43 per cent thought the HPV vaccine should be mandatory. I think the difference in opinion has a lot to do with the “squirm factor” associated with the link between the vaccine and adolescent sexuality.
First the facts. There are numerous types of the human papillomavirus (HPV), but the most problematic ones are types 16 and 18 – together these two account for more than 70 per cent of cervical cancers. Cervical cancer is the second most common form of cancer in women worldwide, and fifth leading cause of death among women. Worldwide HPV is responsible for more than 500,000 cases of cancer and more than 250,000 deaths every year. HPV is also transmitted primarily through sexual contact. One other interesting fact to note: HPV is not a rare virus; approximately 80 per cent of sexually active individuals will be infected with HPV at some point in their life (although only a small percentage of these will lead to cervical cancer). In 2006 the World Health Organization recognized the high efficacy and safety of the vaccine, which has since been administered to more than 120,000,000 people worldwide.
The “squirm factor” arises because the vaccine is only effective at protecting an individual against HPV types to which the individual has never been exposed. And since it is transmitted through sexual contact, this means the vaccine has to be administered to adolescent girls at around age 11 or 12, before they become sexually active. So some people are uncomfortable with the HPV vaccine for the same reason they may be uncomfortable with sex education in schools – they may not like the thought of anything sexually-related being introduced to their children until they feel ready to do so themselves. In fact some have argued against the HPV vaccine on the grounds that it will increase teen promiscuity. However, this is nothing more than a rationalization developed to justify one’s squirm factor. First, the idea is to target girls before they become sexually active; so unless the one reason preventing girls from becoming sexually active is fear of HPV (which is highly, highly unlikely), the vaccine isn’t going to increase the number of adolescent girls becoming sexually active. Besides, empirical studies have examined this hypothesis and have found that the introduction of the HPV vaccine has not been associated with increased sexual activity among adolescent girls.
The other thing that is unique about the HPV vaccine is that, unlike other vaccines, the herd immunity argument doesn’t apply. One of the reasons for vaccinating one’s children against MMR and the like is that a sufficiently large enough percentage of the population must be vaccinated against those viruses to prevent resurgence (as we have recently seen with measles). So an individual’s decision not to vaccinate his or her children does diminish the larger community’s level of immunity. In the case of HPV, while the unvaccinated could spread HPV to other unvaccinated individuals, the mode of transmission is different (were’ not likely to ever see an HPV outbreak at Disneyland). So the decision to vaccinate one’s adolescents against HPV is much more about the risk to the individual and much less about the good of the community.
Other reasons for resistance to the HPV vaccine are the same as with other vaccines: concerns about side effects, fears of Big Pharma conspiracies, and lack of knowledge of the facts. There are some people who will remain anti-vaccine no matter what the vaccine is or how much data is presented. Some people still believe that vaccines might cause autism. A recent survey published in the National Post, conducted right around the time that the measles outbreak peaked, showed that 80 per cent of the anti-vaxxers surveyed said they were “not at all likely” to change their position in response to the outbreak. The reality is that no medical treatment, vaccine or otherwise, is without some degree of risk. The important question is always whether the benefits outweigh the risks.