HPV vaccine should be part of back-to-school routine for girls and boys: A discussion with Dr. Sanaz Memarzadeh

Human papillomavirus (HPV) is the most common sexually-transmitted infection in the United States—yet vaccination for HPV continues to remain low.

According to the Centers for Disease Control and Prevention (CDC), about 39,800 HPV-associated cancers occur in the United States each year—about 23,300 in women and 16,500 in men. Cervical cancer is the most common HPV-associated cancer among women and oropharyngeal cancers are the most common among men.

Overall, HPV is thought to be responsible for more than 90% of anal and cervical cancers, about 70% of vaginal and vulvar cancers, and more than 60% of penile cancers. Fortunately, the HPV vaccine (if administered on schedule) provides almost 100% protection from HPV types 6, 11, 16, and 18.

However, only 5 out of 10 boys and 6 out of 10 girls in the US have started the HPV vaccine series, CDC reported.

Sanaz Memarzadeh, MD, PhD, of the David Geffen School of Medicine at UCLA

As children and teens head back to school, now is a good time to make sure the HPV vaccine is part of their routine vaccinations. In this interview, oncologist and researcher Sanaz Memarzadeh, MD, PhD, of the David Geffen School of Medicine at UCLA, stresses the importance of this vaccine in preventing cancer. She also explains why some clinicians may hesitate to recommend the HPV vaccine and what they can do to encourage their patients to be vaccinated.

MDLinx: Why have some physicians been reluctant to recommend the HPV vaccine?

Dr. Memarzadeh: The community of physicians has done a great job on this already. But, we can always do better. Improving HPV vaccination has been largely a collaborative effort between the gynecology community, pediatricians, and experts in infectious disease.

The gynecologists (general gynecologists and gynecologic oncologists) see how important vaccination is as they are the doctors diagnosing and treating women with vulvar, vaginal, and cervical cancers. Pediatricians are in an excellent position to recommend and ensure the vaccine is administered at the right time, prior to HPV exposure and prior to the onset of sexual activity (per FDA guidelines).

Reluctance on the clinical community side may be due to three possible factors:

• Lack of familiarity with guidelines for HPV vaccination (age, frequency, interval);
• Need for spending more time to discuss the preventive vaccination option in the midst of busy work schedules;
• Absence of practice-based systems that can ensure the vaccine is administered at the right age and dosing frequency.

HPV is a causative agent for development of many cancers including oropharyngeal, anal, penile, cervical, vulvar, and vaginal cancers. So, more crosstalk among different disciplines that treat these problems (gynecologists, head and neck surgeons, urologists) and those in positions to implement prevention (gynecologists, pediatricians, and infectious disease experts) may help ensure wider spread vaccination.

MDLinx: What are the differences among the types of HPV vaccines?

Dr. Memarzadeh: The major difference between the types of vaccines is the range of coverage. There are hundreds of HPV strains and some of them have a high propensity for causing cancer. The vaccine available and recommended in the US is the 9-valent vaccine (Gardisil 9), which specifically immunizes against nine HPV strains. This vaccine likely has broader coverage beyond the nine HPV subtypes because viral particles used for making the vaccine are shared among different HPV subtypes.

MDLinx: Are there special cases of certain patients who should be vaccinated early or continue to be vaccinated longer than the typical schedule?

Dr. Memarzadeh: The vaccine is most efficacious if it is administered before onset of sexual activity. For those reasons, the FDA has approved vaccination in both females and males between ages 9 and 26. If administered prior to age 15, CDC recommends two doses of the vaccine to be administered 6 months apart. In those who are 15 or older, three doses of the vaccine are recommended at time 0, 2 months, and 6 months. In individuals with an immunocompromising condition, three vaccine doses are recommended irrespective of age.

Generally, the vaccine is recommended to be administered at ages 11 to 12 in both sexes. It can be administered as young as age 9.

MDLinx: Can a patient who is already infected with HPV still be vaccinated?

Dr. Memarzadeh: Yes, they can get vaccinated and there is likely a benefit in doing so. Even if these individuals are infected with one subtype of HPV, they can gain protection against other strains with vaccination. It is important to remember, though, the greatest benefit is to be gained if the vaccination happens prior to HPV exposure (prior to onset of sexual activity).

MDLinx: Has there been any indication yet of reduced incidence of cervical cancer as a result of HPV vaccination in the US?

Dr. Memarzadeh:Large-scale studies have clearly shown that vaccination has already significantly reduced rates of HPV infection and HPV-induced precancerous lesions. Widespread implementation of vaccination will no doubt also result in a reduction in the rate of cervical cancer.

The natural course of HPV-induced cancers is such that there is a long latency period between persistent infection and development of cervical cancer. Given that the HPV vaccine has only been FDA approved and then used since 2006, more time is needed to appreciate reduction in the incidence of invasive cervical cancer.

MDLinx: What do you say to a patient or to the parent who is reluctant—or outright defiant—about vaccination?

Dr. Memarzadeh: I think the first step is education. I would share with them that this is a vaccine that prevents cancer. I would also emphasize that many HPV-induced cancers are difficult to treat, particularly in advanced stages. So, I would share with the parent that this vaccine, which is safe and well tolerated, can save their child's life and prevent unnecessary suffering.

I would also try to understand why the family is reluctant. Vaccination with HPV does not and should not promote sexual promiscuity.

MDLinx: What types of questions should physicians be prepared to answer about HPV?

Dr. Memarzadeh: As physicians, we should know the guidelines for vaccination (timing, dosing strategy, and indications) and feel comfortable discussing the benefits of vaccination with patients.

MDLinx: What strategies can physicians try in order to make it easier to provide the vaccine?

Dr. Memarzadeh: Bundling the HPV vaccine with other vaccines is one potential option. It should be part of a routine checkup evaluation for individuals in the indicated age group.

An alternative strategy is mandating it as part of the vaccination series required in schools. We have a long way to go in preventing HPV-related disease in the US. To date, less than 50% of girls and boys ages 13 to 17 have received the full HPV vaccination series. I have no doubt that with more education and discussions revolving around HVP vaccination, we can do better. Having a vaccine that can prevent cancer is a scientific breakthrough and its implementation will help humanity.

About Dr. Memarzadeh: Sanaz Memarzadeh, MD, PhD, is a gynecologic cancer surgeon and Professor in the Department of Obstetrics and Gynecology, Director of the G.O. Discovery Laboratory, and a member of the Jonsson Comprehensive Cancer Center and Stem Cell Biology Program at UCLA, in Los Angeles, CA.