Vaccine Opponents Haven't Looked at the Evidence

Maurie Markman, MD

In the annals of the relationship between clinical scientists and the general public, there can be no more distressing topic than that of the failure of the scientific community to successfully communicate the unquestionable individual and societal benefits of specific vaccines. Current vaccination policy has substantially improved public health and welfare.

Today, we hear of outbreaks of measles in multiple regions of our country. Measles is a potentially serious, vaccine-preventable illness that until recently was all but eliminated within the boundaries of the United States.¹ And in many areas of the country, mumps is making a disturbing resurgence. There are many explanations for these remarkably disconcerting comebacks, beginning with the simple fact that if a healthrelated condition has been contained by the established vaccination strategy, as happened for measles and polio, it may be difficult for many who have not lived through an outbreak to appreciate how critical it is to never permit the disease to reappear. One can imagine the different perspective parents would have regarding the seriousness of polio and the need to vaccinate their own children if they knew somebody who had suffered the consequences of this preventable illness.

Further, it has been increasingly documented that the internet, far from being the home of useful, authoritative, objectively valid, and truthful information, can serve as a source of conspiracy theories as well as factually incorrect statements and claims regarding the effectiveness of health-related policy measures.² I must emphasize that this misinformation may result in serious negative consequences.³

Unfortunately, one can now add to the list of concerns the openly declared unwillingness of political leaders to support highly scientific, valid approaches to ensure individual and public health. A US senator, remarkably a physician himself who publicly acknowledged that “the benefits of vaccines far outweigh the risks,” has warned of ”sacrificing liberty for a false sense of security.”⁴ How many thousands would have suffered the devastating complications of polio more than 50 years ago if society had dismissed polio vaccination policies as offering a false sense of security?

For evidence of the value of rigorously scientifically valid vaccination policy, look no further than the rapidly accumulating objective data regarding the human papillomavirus (HPV) vaccine for the prevention of cervical and other, potentially carcinogenic, malignancies. Due to the known time required for persistent HPV infection to culminate in invasive cancer, it will be several decades before the prevalence of cervix cancer decreases as a result of vaccination. However, early population-based data are highly encouraging and fully support scientifically based statements regarding the ultimate impact of this public health effort.

An evaluation of a 5-site, HPV population—based surveillance program that examined historical data for 37 types of HPV found remarkable evidence of impact. Among 10,206 cases of HPV in women aged 18 to 39 years, the proportion of cervical intraepithelial neoplasia (CIN) grades 2 to 3 or adenocarcinoma in situ found to be due to HPV 16/18—the types responsible for approximately 70% of cervical cancer worldwide—decreased from 52.7% in 2008 to 44.1% in 2014 (P <.001).⁵ Note that the first HPV vaccine was not introduced in the United States until 2006. Improvements in coverage have since been added.⁵

Not surprisingly, the reduction in HPV 16/18 was most prominent in individuals who were vaccinated at some point during this time—although not necessarily early enough to prevent persistence of HPV following sexual exposure to the virus. There was a significant absolute decline (55.2% to 33.3%; P <.001) in the proportion of HPV 16/18—positive, CIN2-positive cases observed among vaccinated women.

However, even among unvaccinated women, there was a smaller, still statistically significant decline in the proportion of HPV (51.0% to 47.3%; P = .03).⁵ The theory here is that the unvaccinated population benefitted from reduced exposure to HPV 16/18 because it was within the larger population (ie, herd protection). One can easily imagine how the decrease in HPV 16/18 would accelerate if a greater percentage of adolescent girls and boys were to receive this critically important cancer vaccine.

Although substantial additional objective data are available demonstrating the clinical value of HPV vaccination, including for the prevention of HPV-associated head and neck cancers in men and women, I will conclude by noting a recent scientifically rigorous peer-reviewed modeling study published in a high-impact medical journal that highlights the immense impact that would be associated with the successful worldwide implementation of an effective cervical cancer screening (short-term benefit) and HPV vaccination (longer-term benefit) strategy.

As noted in this report, in the absence of a change in the cervical cancer trajectory, there will be an estimated 44.4 million cases of this cancer diagnosed between 2020 and 2069.⁶ However, this realistic model suggests that if international public health efforts could be mobilized such that there was “80% to 100% coverage globally by 2020 with a broad-spectrum HPV vaccine, 6.7 to 7.7 million cases in this period” of cervical cancer could be prevented, recognizing that the greatest benefit from the vaccine would be realized in the later years. This estimate does not include the certain favorable impact of the successful implementation of an HPV vaccination strategy on the incidence of oropharyngeal cancers.

This is the message that needs to be communicated to those who continue to deny the value of recognized safe and effective vaccines. The question is, how does the public health community achieve this critically important goal?

References

1. Sundaram ME, Guterman LB, Omer SB. The true cost of measles outbreaks during the postelimination era. JAMA. 2019;321(12):1155-1156. doi: 10.1001/jama.2019.1506.
2. McMillan R, Abbott B. Facebook cracks down on vaccine misinformation. Wall Street Journal. March 7, 2019. wsj. com/articles/facebook-cracks-down-on-vaccine-misinformation-11551989347. Accessed May 21, 2019.
3. Mervosh S. After contracting tetanus, an unvaccinated boy spent 57 days in the hospital. The New York Times. March 10, 2019. nytimes.com/2019/03/09/well/oregon-child-tetanus-vaccine.html. Accessed May 21, 2019.
4. The New York Times editorial board. Measles is making a comeback. Here’s how to stop it. The New York Times. March 11, 2019. nytimes.com/2019/03/11/opinion/measles-outbreak-vaccines.html. Accessed May 21, 2019.
5. McClung NM, Gargano JW, Bennet NM, et al; IMPACT Working Group. Trends in human papillomavirus vaccine types 16 and 18 in cervical precancers, 2008-2014. Cancer Epidemiol Biomarkers Prev. 2019;28(3). doi: 10.1158/1055-9965.EPI-18-0885.
6. Simms KT, Steinberg J, Caruana M, et al. Impact of scaled up human papillomavirus vaccination and cervical screening and the potential for global elimination of cervical cancer in 181 countries, 2020-2099: a modeling study. Lancet Oncol. 2019;20(3):394-407. doi: 10.1016/S1470-2045(18)30836-2.