Quadrivalent Human Papilloma virus

The quadrivalent human papillomavirus (HPV) vaccine is a recombinant preventive vaccine designed to protect against four HPV types: 6, 11, 16, and 18. It contains virus-like particles made from the L1 proteins of these types. These particles resemble the outer structure of HPV but contain no viral genetic material, so they cannot cause HPV infection. Vaccination stimulates the immune system to produce antibodies that help prevent infection with the targeted HPV types. Types 16 and 18 are responsible for a substantial proportion of cervical and other HPV-related cancers, while types 6 and 11 cause most genital warts. The vaccine is administered by intramuscular injection and is intended to be given before exposure to HPV, which is why vaccination during early adolescence is commonly recommended. Depending on the product, age at the first dose, immune status, and national guidance, vaccination may require one, two, or three doses. The quadrivalent vaccine prevents new infections but does not treat existing HPV infection, genital warts, or established precancerous lesions. It does not cover every cancer-causing HPV type, so eligible individuals may still need cervical screening and other recommended preventive care.

Quadrivalent HPV vaccines were developed using recombinant technology to produce non-infectious virus-like particles that stimulate protective antibody responses. The first widely used quadrivalent product, Gardasil, received US Food and Drug Administration (FDA) approval in June 2006 and European Commission marketing authorisation on 20 September 2006 following assessment by the European Medicines Agency (EMA). Its original indications focused on preventing HPV-related precancerous lesions and cancers and genital warts caused by the four targeted types. Clinical development included large phase III studies evaluating prevention of persistent infection, genital warts, and cervical and other precancerous lesions. In India, a quadrivalent HPV vaccine called Cervavac has also received national regulatory approval. Product-specific indications, approved ages, and schedules differ across jurisdictions. The World Health Organization (WHO) issued updated HPV vaccine recommendations in December 2022, including reduced-dose schedules for eligible populations; these public-health recommendations may differ from the licensed schedule for a particular product.

The quadrivalent HPV vaccine is used to prevent infection and disease associated with HPV types 6, 11, 16, and 18. Depending on the specific product label, approved uses include prevention of cervical, vulvar, vaginal, and anal cancers; related precancerous or dysplastic lesions; and genital warts. Vaccination is intended for eligible girls and boys, women and men within the age ranges specified by local product information and immunisation guidance. The greatest preventive benefit generally occurs when vaccination is completed before exposure to HPV. The vaccine is prophylactic rather than therapeutic: it does not clear an existing infection or treat established HPV-related disease. It may be given as part of a routine immunisation programme or as catch-up vaccination, depending on age and national recommendations. It does not replace cervical screening or evaluation of suspicious lesions.

The vaccine is administered by intramuscular injection, usually into the deltoid muscle of the upper arm. The dose for standard quadrivalent HPV vaccine products is generally 0.5 mL per injection. The number and timing of doses depend on the specific product, age at the first dose, immune status, and national guidance. Some licensed schedules use two doses for younger adolescents and three doses for people starting vaccination at older ages or for those who are immunocompromised. WHO also recommends reduced-dose schedules for certain populations; these should be applied according to national policy and the relevant product guidance. If a dose is delayed, the vaccination series generally does not need to be restarted, but the appropriate catch-up schedule should be confirmed with a healthcare professional. The vaccine should be stored and handled according to the product's cold-chain requirements and administered by trained personnel.

Common side effects include pain, redness, swelling, or tenderness at the injection site, headache, mild fever, dizziness, nausea, and muscle or joint discomfort. Some individuals may feel faint during or shortly after vaccination, particularly adolescents, so observation while seated or lying down is appropriate. Symptoms are usually mild and resolve without specific treatment. Side effects may vary according to the individual and vaccine product. Patients should tell the vaccinator about previous reactions to vaccines, severe allergies, or current illness before receiving a dose. Persistent, worsening, or unusual symptoms should be assessed by a healthcare professional.

Severe allergic reactions, including anaphylaxis, are rare but potentially serious. A severe allergic reaction to a previous dose or a vaccine component is a contraindication to further vaccination with that product. People with a significant acute illness may need vaccination postponed until they recover, while a mild illness is not usually a reason to delay it. Fainting can occur around the time of injection and may result in injury, so recipients should be observed after vaccination. Available safety monitoring supports the use of HPV vaccines according to approved recommendations. The quadrivalent vaccine does not protect against every HPV type associated with cancer, and vaccination does not eliminate the need for recommended screening. Suspected serious adverse reactions require prompt medical evaluation and reporting through the applicable vaccine-safety system.

Before vaccination, review the individual's age, previous HPV vaccine doses, history of severe allergic reactions, immune status, and current health. People with weakened immune systems may have a reduced response and should follow the schedule recommended for their circumstances. Pregnancy is generally a reason to defer remaining HPV vaccine doses until after pregnancy; accidental vaccination during pregnancy is not, by itself, an indication for intervention. Breastfeeding is not generally a contraindication, but the applicable product information should be checked. HPV vaccines are non-live vaccines and cannot cause HPV infection. They may be administered alongside certain other vaccines at different injection sites when permitted by local guidance. Classic drug interactions are not generally expected, although immunosuppressive treatments may reduce the immune response. The vaccine is preventive and should not be used to treat active HPV infection or HPV-related lesions.

Confirm the exact quadrivalent vaccine product and check its current local prescribing information before selecting an age-specific schedule. Review the vaccination record to avoid unnecessary repeat doses and document the product, batch number, dose, date, and injection site. Maintain the required cold chain and inspect the vaccine before administration. Screen for a history of severe allergic reactions and ensure that appropriate emergency treatment for anaphylaxis is available. Keep recipients seated or lying down during vaccination when appropriate and observe them afterward to reduce injury from fainting. Explain that vaccination works best before HPV exposure, prevents disease caused by targeted types, and does not treat existing infection or replace cervical screening. For people who are immunocompromised, pregnant, or have an incomplete vaccination history, confirm the appropriate schedule with current national guidance. Report suspected serious adverse events through the relevant pharmacovigilance system.