Human papillomavirus, oropharyngeal cancer, and the latest vaccine: considerations for oral healthcare providers

Human papillomavirus (HPV) is associated with both benign and malignant disorders, such as genital warts and a variety of cancers, including oropharyngeal squamous cell carcinomas (OPSCCs). The current 9-valent HPV vaccine (Gardasil 9) protects against high-risk strains that have been shown to cause OPSCC, and widespread vaccination should reduce the rate of all HPV-associated cancers. HPV-related OPSCCs differ from non-HPV-related OPSCCs in their clinical presentations and responsiveness to treatment. To provide oral healthcare providers with a basis for effective com-munication with patients, this article will examine the evolution of the HPV vaccination schedule and the role of the HPV vaccine in the prevention of OPSCCs.

Human Papillomavirus Vaccinations: Provider Education to Enhance Vaccine Uptake

Human papillomavirus (HPV) is the number one sexually transmitted infection (STI) worldwide. The Centers for Disease Control and Prevention (CDC) approximated that 92% of HPV-related cancers might be prevented by receiving the HPV 9-valent vaccine (Gardasil 9). The 2-dose HPV vaccine for children ages 11 to 12 years provides almost 100% protection against strains affiliated with cervical, vaginal, and vulvar cancers. Provider education is essential to decrease clinical knowledge deficits and increase vaccination uptake. Evidence-based provider recommendations expressed to eligible individuals improves vaccination rates. Evidence-based approaches for vaccine-hesitant parents involve using the presumptive announcement approach, asking for and addressing main concerns, and trying again if the parent initially declines. Seventy percent of parents who initially decide not to get their child vaccinated later agree to the vaccine or schedule a follow-up appointment. The CDC guidelines for HPV vaccinations, including the catch-up and adult guidelines, are reviewed. A clinical vignette with case scenarios and a Q&A quiz are included.

Non-sexual HPV transmission and role of vaccination for a better future (Review)

Human papilloma viruses (HPVs) belong to the Papillomaviridae family and are epitheliotropic infecting squamous epithelia (skin and mucosae). HPV is estimated to be the cause of 99% of cervical cancers (there is no evidence of significant genetic predisposition for cervical cancer), 90% of anal cancer, 65% vaginal cancers, 50% vulvar cancers, and 45-90% oropharyngeal cancers. The route of HPV transmission is primarily through skin-to-skin or skin-to-mucosa contact. Sexual transmission is the most documented, but there have been studies suggesting non-sexual courses. The horizontal transfer of HPV includes fomites, fingers, and mouth, skin contact (other than sexual). Self-inoculation is described in studies as a potential HPV transmission route, as it was certified in female virgins, and in children with genital warts (low-risk HPV) without a personal history of sexual abuse. Vertical transmission from mother to child is another HPV transfer course. Several studies have emphasized the possibility of infection through the amniotic fluid, or the placenta, or via contact with maternal genital mucosa during natural birth. Waterborne transmission of HPV has never been demonstrated; however, HPV DNA has been detected in water environments. Routine hygiene measures are proven to be inefficient in preventing HPV transmission, as the studies which have evaluated samples of HPV on contaminated medical equipment (after standard disinfection) have found them to be still positive. Annual costs associated with the morbidity and mortality of HPV-related diseases are estimated at approximately $4 billion. Once the HPV vaccine program in Australia was launched, many studies reported the initial effects: A decrease in the incidence of high-grade cervical abnormalities, no new genital warts cases in females under 21 years. Promoting greater understanding in the general public about the evident benefits of vaccination can create positive vaccine attitudes and scatter the myths of spurious side effects.

Human Papillomavirus Vaccines: An Updated Review

Human papillomavirus (HPV) vaccines, which were introduced in many countries in the past decade, have shown promising results in decreasing HPV infection and related diseases, such as warts and precancerous lesions. In this review, we present the updated information about current HPV vaccines, focusing on vaccine coverage and efficacy. In addition, pan-gender vaccination and current clinical trials are also discussed. Currently, more efforts should be put into increasing the vaccine’s coverage, especially in low- and middle-income countries. Provision of education on HPV and vaccination is one of the most important methods to achieve this. Vaccines that target HPV types not included in current vaccines are the next stage in vaccine development. In the future, all HPV-related cancers, such as head and neck cancer, and anal cancer, should be tracked and evaluated, especially in countries that have introduced pan-gender vaccination programs. Therapeutic vaccines, in combination with other cancer treatments, should continue to be investigated.

The nonavalent vaccine: a review of high-risk HPVs and a plea to the CDC

Two of the leading strategies to prevent cervical cancer are prophylactic human papillomavirus (HPV) vaccination and routine Papanicolaou (Pap) testing. However, regardless of being vaccinated with first-generation (bivalent and quadrivalent) HPV vaccines at the recommended dosing schedule, many women are still found to have low- and high-grade cervical intraepithelial lesions. Studies have shown that this is largely due to: (1) first-generation vaccines only protecting against 70% of high-risk HPV types that cause cervical cancer (HPVs 16/18) and (2) vaccinated women being more prone to infection with non-protected high-risk HPV types than unvaccinated women. Fortunately, the FDA recently approved a nonavalent vaccine that protects against 5 additional high-risk HPV types that cause 20% of cervical cancers (HPVs 31/33/45/52/58), which is the only HPV vaccine currently available in the United States. Although the Advisory Committee on Immunization Practices (ACIP) recommends the nonavalent vaccine in men and women up to the age of 45 years, it does not recommend the nonavalent vaccine in those previously vaccinated with 3 doses of bivalent or quadrivalent vaccine, deeming them "adequately vaccinated". As this population is most at risk, this review serves to provide background and argue for a change in their recommendation.

A prospective, single-arm, open-label, non-randomized, phase IIa trial of a nonavalent prophylactic HPV vaccine to assess immunogenicity of a prime and deferred-booster dosing schedule among 9-11 year-old girls and boys - clinical protocol

BACKGROUND

Human papillomavirus (HPV) vaccines are indicated for the prevention of cancers and genital warts caused by vaccine-covered HPV types. Although the standard regimen requires a two or three-dose vaccine series, there is emerging data suggesting that a single dose of the bivalent or quadrivalent HPV vaccine generates persistently positive antibody titers. No similar data is yet available for the nonavalent HPV vaccine, currently the only HPV vaccine available in the United States. The overall objective of our study is to assess the stability and kinetics of antibody titers for 24 months following a single dose of the nonavalent HPV vaccine among preteen girls and boys.

METHODS

This is a prospective, single-arm, open-label, non-randomized, Phase IIa trial among 9-11 year-old girls and boys to determine the immunogenicity after a single dose of the nonavalent HPV vaccine (GARDASIL® 9) over 24 months, with a deferred booster dose at 24 months and an optional booster at 30 months after the first dose. Participants provide blood specimens at 6, 12, 18, 24, and 30 months after the first dose. Serologic geometric mean titers (GMT) of the nine vaccine types (HPV 16/18/ 6/11/31/33/45/52/58) will be measured at each time point. The primary objective is to determine the stability of type-specific serologic GMT of HPV16 and HPV18 between the 6- vs. 12-month, 12- vs. 18-month, and 18- vs. 24-month visits. Secondary objectives are to determine the stability of type-specific serologic GMT of the other HPV types (HPV 6/11/31/33/45/52/58) between the visits and to assess safety and reactogenicity after each vaccine dose.

DISCUSSION

Single dose HPV vaccination could simplify the logistics and reduce costs of HPV vaccination in the US and across the world. This study will contribute important immunogenicity data on the stability and kinetics of type-specific antibody titers and inform feasibility of the single dose HPV vaccination paradigm.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02568566 . Registered on October 6, 2015.

Human papilloma virus vaccination: Review article and an update

Human papilloma virus (HPV) is sexually transmitted and associated with uterine cervix, vaginal, and vulvar cancers in females, oropharyngeal and anal cancer in both genders, and penile cancer in males. Moreover, genital warts are benign tumors which are HPV-related and can occur in both genders. This is a review of HPV structure, HPV infection transmission, the global impact of HPV and its associated diseases, HPV vaccines and their efficacy and safety, public acceptance of HPV vaccines, the obstacles for its acceptance and strategies to address the barriers. Cervarix (a bivalent vaccine with protection against HPV types 16 and 18) and Gardasil (a quadrivalent vaccine with protection against HPV types 6, 11, 16 and 18) are 2 recommended vaccines. The longest follow up of 9.4 years has shown efficacy and protection of the vaccine against HPV types 16 and 18. The adverse effects have been minimal and the vaccine is considered safe. Numerous studies are conducted to follow the vaccinated individuals to better understand the effect of HPV vaccine on incidence of HPV-related cancers and precancerous lesions.