HPV vaccine

The human papillomavirus (HPV) vaccine is a prescription medication in the vaccine class.

The Human Papillomavirus (HPV) vaccine is approved to prevent several cancers and diseases caused by HPV, including genital warts, anal and oropharyngeal cancers.

It is administered to adolescent girls as part of routine national immunization programs.

The HPV vaccine is administered by injection, prompting an immune response without undergoing typical drug metabolism and elimination. It triggers the production of antibodies, providing long-term defence against HPV infection.

The common side effects of the HPV vaccine may include Pain, redness at the injection site, fever, fatigue and headache.

HPV vaccines are available as a suspension for injection.

HPV vaccines are available in many countries like the United States, Canada, the United Kingdom, Australia, and various European and Asian nations.

The HPV vaccine class stimulates immunity by producing antibodies against the Human Papillomavirus.

Due to the virus's specific human tropism, the exact mechanism of action of the 9-valent Human Papillomavirus (9vHPV) vaccine is not entirely understood. However, the vaccination mainly works by enhancing the humoral immune response.

The 9vHPV vaccine is produced synthetically utilizing virus-like particles (VLPs) produced from the L1 protein components of human papillomavirus (HPV) types like 6, 11, 16, 18, 31, 33, 45, 52, and 58. These VLPs are chemically inert and do not spread disease. They cause the formation of neutralizing antibodies when administered orally.

According to a 2016 immunogenicity research, the vaccine's inactive HPV L1 VLPs significantly promote the production of antibodies that neutralize the targeted HPV strains. This immune response protects against diseases and dysplastic lesions linked to HPV infections. The study also showed that the antibody levels produced by the 9vHPV vaccination are significantly higher than those produced by a natural HPV infection, ranging from 10 to 100 times more substantial. This shows that the humoral immune response, which has sufficient antibodies to prevent HPV-related diseases successfully, is the primary mechanism by which the vaccine's efficacy is mediated.

HPV vaccines are available as a suspension for injection.

Suspension for injection: To be administered parenterally, as applicable.

HPV vaccines can be used as follows:

• Immunizing with the HPV vaccine can protect against diseases/precancerous conditions caused by human papillomavirus (HPV) types like 6, 11, 16, 18, 31, 33, 45, 52, and 58
• To prevent cervical, anal, and oropharyngeal cancers caused by HPV infections.
• Reduces the risk of HPV-associated diseases in both males and females.

HPV vaccine can help support the following health benefits:

• Prevention: The HPV vaccine's prevention of certain cancers is one of its most significant benefits. Cervical, vaginal, vulvar, anal, and oropharyngeal (throat) cancers can all be caused by HPV which is a sexually transmitted infection. Before they initiate sexual activity, teenagers and young adults can get vaccines that significantly decrease their chance of developing certain diseases in adulthood.
• Community Health: Herd immunity, which prevents the virus from spreading when a significant percentage of the population is immunized, is developed by widespread HPV vaccination. This provides indirect protection to people who have not received a vaccination and direct protection to those who did. Herd immunity is even more necessary for people who cannot accept the vaccination due to medical conditions or a lack of access.
• Genital Warts: Besides protecting against cancer, HPV vaccinations protect against highly infectious, benign illnesses like genital warts, which certain virus strains have caused. Even while they aren't considered a life-threatening hazard, they can be uncomfortable and distressing and sometimes require medical assistance to get eradicated. Genital wart incidence is significantly decreased with immunization.
• Long-term on public health: The advantages of receiving an HPV vaccine extend much beyond one's health. A generation shift in disease may result from the continuing fall in HPV-related disease incidence as more individuals get vaccinated. As a result, future generations will experience a decreased risk of HPV-related malignancies and comorbidities, improving the general state of public health. The long-term effects of HPV vaccination may lower the burden of cancer-related disorders and the cost of accompanying medical treatment.

HPV vaccines are approved for use in the following clinical indications:

• Preventing cervical cancer and some forms of papillomavirus-related premalignant anogenital lesions, particularly of the cervix.
• The quadrivalent vaccination prevents anogenital warts caused by certain papillomavirus types, particularly types 6 and 11.

Parenterally: HPV vaccine is available as a suspension for injection. It should be shaken thoroughly before use to ensure that it is appropriately suspended and administered in the upper arm's deltoid or higher anterolateral area of the thigh. After injection, monitor patients for 15 minutes for any post-administration adverse reactions.

It should be administered intramuscularly only and not intravenously, intradermally or subcutaneously.

It can be only given by a healthcare professional in a hospital setting or during routine immunization programs.

After administration, the healthcare provider will document the vaccination, including the date, time, dose, and injection site.

The dosage and duration of treatment should be as per the treating physician's clinical judgment.

HPV vaccine is available as a suspension for injection.

Suspension for injection: 0.5mL/single-dose vial or syringe

Dosage Adjustment for Adult Patients

Immunization against HPV Infection

0.5 mL Intramuscularly as a 2 or 3-dose series depending on age at first vaccination

Adults under the age of 26

Recommended as a preventative measure for all people up to the age of 26

Initial vaccination

More than 15 years: A three-dose course should be taken at 0, 1, and 6 months (minimum intervals between doses should be 4 weeks, 12 weeks, and 5 months, respectively; dosage should be repeated if given too soon).

9 to 14 years: Given 1 dose of 0.5 mL intramuscularly

9 to 14 years: Given 2 doses at least 5 months apart and is recommended to complete HPV vaccination

Adults aged 27-45 years

Immunization must be given based on shared decisions between the patient and the practitioner.

Depending on the age at the first immunization, a 2- or 3-dose series of HPV can be given.

HPV vaccine should be used to prevent HPV virus, along with no appropriate dietary restrictions. Consuming regular foods and drinks before and after receiving the vaccine is safe.

However, staying fully hydrated and maintaining a balanced and healthy diet to support overall immune system function is always recommended, which can boost the effectiveness of vaccines.

The dietary restriction should be individualized as per patient requirements.

HPV vaccine may be contraindicated in the following conditions: -

• Anaphylaxis reactions (Hypersensitivity to yeast since 9vHPV is a recombinant vaccine expressed in Saccharomyces cerevisiae/brewer's yeast)
• Pregnancy
• Allergic to latex rubber (pre-filled syringe form)
• Immunodeficiency disorders like HIV/AIDS infection

• Severe previous response to the HPV vaccination

The treating physician must closely monitor the patient and keep pharmacovigilance as follows.

• Children with weak immune systems, such as those with HIV/AIDS infection or cancer or who are taking certain drugs, may not respond as well to the HPV vaccine and may consult a healthcare professional who might suggest modifying the vaccine schedule or giving additional doses to these people to improve protection.
• It may be advisable to postpone the vaccination if the child is currently experiencing a fever, minor infections or a moderate to severe sickness.
• Healthcare professionals should assess the risks and benefits of the vaccination in case of any severe allergic reactions or a severe reaction to a previous dose of the HPV vaccine.
• When administering the HPV vaccine simultaneously with HPV immunoglobulin or other vaccines, it is recommended to use separate syringes and distinct injection sites.

Caution is advised when consuming alcohol with the HPV vaccine

There is no sufficient scientific evidence traceable regarding the use and safety of the HPV vaccine in the breastfeeding population.

Unsafe to use during pregnancy.

There is no sufficient scientific evidence traceable regarding the use and safety of the HPV vaccine in concurrent use with any particular food.

The clinically relevant drug interactions of the HPV vaccine are briefly summarized here:

• Immunosuppressants- Drugs like prednisone or cyclosporine when used in very high doses suppress the immune system and may reduce the effectiveness of the HPV vaccine when used.
• Other Vaccines: Children are administered different vaccines to reduce risk; it is generally recommended to help them at separate sites and times from the HPV vaccine to minimize the risk of interference. Other live vaccines should be administered at least four weeks apart to avoid the risk of one immune response interfering with another.

The common side of the HPV vaccine includes the following-

• Pain, erythema or swelling where the shot was given
• Itching, bruising, bleeding, or a hard lump at the injection site
• Feeling tired
• Headache
• Nausea
• Dizziness
• Headache
• Vomiting
• Diarrhea
• Fever
• Rash
• Sore throat
• Abdominal (belly) Pain

The HPV vaccine should be prudent in the following group of special populations.

• Pregnancy: Pregnant women are at risk for HPV (Human Papillomavirus), which may result in genital warts or issues like pulmonary papillomatosis in neonates delivered vaginally. In general, administering an HPV vaccination during pregnancy is not advised. Avoid the HPV vaccine unless recommended by a healthcare professional while pregnant.

• Paediatrics: Human Papillomavirus (HPV) vaccination in childhood provides protection against common HPV-related diseases later in life, such as genital, cervical, and throat cancers. Early vaccination ensures long-term benefits and lowers the chance of significant health problems in adulthood.

Dosage Adjustment for Paediatric Patients

Routine HPV vaccination is advised from age 11 to 12 (but can begin as early as 9).

Catch-up vaccination

0.5 mL Intramuscularly as a 2- or 3-dose series, depending on age at initial vaccination

Ages 9 to 14 at the time of the initial immunisation: Two doses separated by a minimum of five months, with a repeat dosage if the first dose was given too soon.

Age 15 at the time of the first vaccination: A three-dose course should be taken at 0, 1, and 6 months (minimum intervals between doses should be 4 weeks, 12 weeks, and 5 months, respectively; dosage should be repeated if given too soon).

Special situations

Immunocompromising conditions such as HIV infection: three doses, as before

History of sexual abuse or assault: Recommended to start at age 9 years

• Geriatrics: There is no sufficient scientific evidence traceable regarding the use and safety of the HPV vaccine for geriatric populations. Avoid taking unless advised to do so by a healthcare professional.
• Lactating mothers: There is no sufficient scientific evidence traceable regarding the use and safety of the HPV vaccine for lactating mother populations.

Dosage Adjustment in Kidney Impairment

There are no specific dosage adjustments provided.

Dosage Adjustment in Hepatic Impairment

There are no specific dosage adjustments provided.

Overdosage of the HPV vaccine rarely occurs as healthcare professionals administer it according to specific or precise dosing guidelines. If multiple doses were accidentally administered, it could be prevented by implementing measures such as proper record-keeping and verifying previous vaccinations.

There is no specific antidote or treatment for excessive intake of the HPV vaccine. Medical attention should be sought immediately when an overdose is suspected, followed by monitoring any adverse effects or allergic reactions. Supportive therapy should also be given, addressing any symptoms that persist or worsen. Physical treatment might be added if necessary.

Pharmacodynamics of HPV vaccine:

The Human Papillomavirus (HPV) vaccines have a physiological mechanism that plays a role in their pharmacodynamics.

The Human Papillomavirus (HPV) vaccination acts by increasing the body's immune response to specific strains of the HPV. Virus outer shell proteins are present, enabling the immune system to detect and produce antibodies to fight viruses. This helps the body ready to fight off HPV infections immediately. The vaccination primarily targets HPV strains 16 and 18, which have been associated with several malignancies. The vaccination significantly decreases the risk of genital warts and malignancies associated with HPV by enhancing the body immune system's ability to detect and kill these viruses, offering crucial protection to the individuals who receive it.

Pharmacokinetics of HPV vaccine:

Absorption: HPV vaccines are typically administered directly into the muscle tissue, bypassing the absorption from the gastrointestinal tract.

Distribution: After being administered, the vaccine's active ingredients enter the bloodstream and trigger an immunological response. They circulate throughout the body, reaching lymph nodes and other parts of the immune system where the immune response is produced.

Unlike drugs, HPV vaccines don't involve metabolism or elimination processes because vaccines contain inert viral proteins, not active drugs. The vaccine's effectiveness comes from the body's immune response and antibody production, which provides long-term defence against HPV infections and related diseases.

• Charde, S. H., & Warbhe, R. A. (2022). Human Papillomavirus Prevention by Vaccination: A Review Article. Cureus, 14(10). https://doi.org/10.7759/cureus.30037Patel, Cyra et al. "The impact of 10 years of human papillomavirus (HPV) vaccination in Australia: what additional disease burden will a nonavalent vaccine prevent?." Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin vol. 23,41 (2018): 1700737. doi:10.2807/1560-7917.ES.2018.23.41.1700737
• Schiller, John T et al. "A review of clinical trials of human papillomavirus prophylactic vaccines." Vaccine vol. 30 Suppl 5,0 5 (2012): F123-38. doi:10.1016/j.vaccine.2012.04.108
• Kurosawa, Megumi et al. "Long-Term Effects of Human Papillomavirus Vaccination in Clinical Trials and Real-World Data: A Systematic Review." Vaccines vol. 10,2 256. 8 Feb. 2022, doi:10.3390/vaccines10020256

• Inform the caregivers of the schedule for administering the HPV vaccine, which usually involves two to three doses over six months and also mentions the importance of completing the vaccination.
• Assure caregivers that HPV vaccine immunizations are generally safe, with only minor, short side effects. Encouraging them to immediately report any unexpected or severe responses to the healthcare physician and, whenever applicable, to use reporting systems like the Vaccine Adverse Event Reporting System (VAERS)
• Inform caregivers of the recommended immunization schedule, which usually consists of two or three doses, depending on the vaccine brand. Also, mention the ages at which the doses should be administered and give the Vaccine Information Statements, which must be disclosed before immunization by the National Childhood Vaccine Injury Act of 1986 about the Centres for Disease Control and Prevention (CDC) website (www.cdc.gov/vaccines), these resources are freely accessible.

• https://www.indianpediatrics.net/
• https://medicalguidelines.msf.org/en/
• https://www.ncbi.nlm.nih.gov/books/NBK562186/
• http://www.cdc.gov/vaccines/schedules/hcp/index.html