The human papillomavirus (HPV) is a common sexually transmitted infection that can lead to various health problems, including several types of cancer and genital warts. While many HPV infections resolve on their own, persistent infections can have serious consequences. The nonavalent HPV vaccine, known as Gardasil 9, helps prevent these HPV-related diseases. It offers broad protection against multiple HPV types.
Understanding “Nonavalent” Protection
The term “nonavalent” means the HPV vaccine protects against nine specific types of human papillomavirus: 6, 11, 16, 18, 31, 33, 45, 52, and 58. Types 16 and 18 cause about 70% of cervical cancer cases globally, while types 6 and 11 cause about 90% of all genital warts.
The vaccine’s broader coverage, including types 31, 33, 45, 52, and 58, accounts for an additional 20% of cervical cancers. These types also contribute to other HPV-related cancers of the anus, vulva, vagina, penis, and oropharynx (throat and back of mouth).
Who Benefits from Vaccination
HPV vaccination is recommended for specific age groups. The Centers for Disease Control and Prevention (CDC) and the Advisory Committee on Immunization Practices (ACIP) recommend HPV vaccination for children at ages 11 or 12 years, and it can begin as early as 9 years of age.
Catch-up vaccination is advised for individuals who did not receive the vaccine during their preteen years. It is recommended for females through age 26 and males through age 21 who have not been adequately vaccinated. For adults aged 27 through 45 years who were not adequately vaccinated, a discussion with a healthcare provider about individual risks and benefits can determine if vaccination is appropriate. While the vaccine is most effective before HPV exposure, it can still provide protection for older individuals.
Vaccination Guidelines
The dosing schedule for the nonavalent HPV vaccine varies based on the individual’s age at the time of the first dose. For most persons initiating vaccination at ages 9 through 14 years, a two-dose series is recommended. The second dose should be administered 6 to 12 months after the first.
Individuals who initiate vaccination at ages 15 through 45 years receive a three-dose series. This schedule involves doses at 0, 1-2 months, and 6 months from the first dose. The vaccine is administered as an injection, usually into the muscle of the upper arm.
Safety and Efficacy Profile
The nonavalent HPV vaccine has undergone rigorous testing and continuous monitoring, demonstrating a favorable safety record. Common side effects are mild and localized to the injection site, including pain, swelling, and redness. Other reported side effects include headache, fever, dizziness, nausea, and fatigue.
The vaccine is highly effective in preventing infections caused by the targeted HPV types and associated diseases. Clinical trials have shown Gardasil 9 to be effective in preventing abnormal changes or cancer in the cervix, vulva, or vagina caused by HPV types 31, 33, 45, 52, and 58. HPV vaccination provides safe, effective, and long-lasting protection against HPV-related cancers.