Human Papillomavirus Quadrivalent Vaccine, Recombinant

Usage

• Medical Conditions: Human Papillomavirus Quadrivalent (Types 6, 11, 16, and 18) Vaccine, Recombinant is prescribed for the prevention of diseases caused by the human papillomavirus (HPV) types 6, 11, 16, and 18. This includes the prevention of:

  • Cervical, vulvar, vaginal, and anal cancers (caused by HPV types 16 and 18)
  • Genital warts (condyloma acuminata) (caused by HPV types 6 and 11)
  • Precancerous or dysplastic lesions of the cervix, vulva, vagina, and anus (caused by HPV types 6, 11, 16 and 18)

• Pharmacological Classification: Vaccine (viral vaccine)

• Mechanism of Action: The vaccine stimulates the body’s immune system to produce antibodies against HPV types 6, 11, 16, and 18. These antibodies prevent the viruses from infecting cells, thus preventing the development of HPV-related diseases.

Alternate Names

• International/Regional Variations: Human Papillomavirus Vaccine (HPV vaccine)
• Brand Names: Gardasil, Cervarix (bivalent)

How It Works

• Pharmacodynamics: The vaccine triggers an immune response, specifically the production of neutralizing antibodies against the L1 proteins of HPV types 6, 11, 16, and 18. These antibodies prevent the virus from attaching to and entering host cells, effectively blocking infection.

• Pharmacokinetics: The vaccine is administered intramuscularly. The virus-like particles (VLPs) in the vaccine are taken up by antigen-presenting cells, which process and present the viral antigens to the immune system. This leads to the production of specific antibodies. Information regarding specific metabolic pathways and elimination routes of the VLPs is limited.

• Mode of Action: The vaccine does not contain live virus but instead includes non-infectious VLPs composed of the L1 protein. These VLPs mimic the structure of the HPV virus, eliciting a robust antibody response without causing infection. The induced antibodies bind to incoming HPV particles, preventing infection by inhibiting viral attachment to host cells.

• Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation: This vaccine primarily works through antibody-mediated immunity, not through direct receptor binding, enzyme inhibition, or neurotransmitter modulation.

• Elimination Pathways: Data on the specific elimination pathways is limited but likely involves immune-mediated clearance and protein degradation.

Dosage

Standard Dosage

Adults (15-45 years):

• 0.5 ml intramuscularly, administered as a 3-dose series (0, 2, and 6 months).

Children (9-14 years):

• 0.5 ml intramuscularly, administered as a 2-dose series (0 and 6-12 months). If the interval between doses is less than 5 months, a third dose is needed.

Special Cases:

• Elderly Patients (over 45): Not routinely recommended. Shared clinical decision-making for ages 27-45 based on individual risk factors.

• Patients with Renal Impairment: No specific dose adjustment is necessary.

• Patients with Hepatic Dysfunction: No specific dose adjustment is necessary.

• Patients with Comorbid Conditions: No specific modifications unless an immunocompromising condition is present. Immunocompromised individuals (including HIV-positive) should receive a 3-dose series (0, 1-2, and 6 months).

Clinical Use Cases

The HPV vaccine is for preventative use, not for treatment of acute conditions. It has no role in:

• Intubation
• Surgical Procedures
• Mechanical Ventilation
• Intensive Care Unit (ICU) Use
• Emergency Situations (e.g., status epilepticus, cardiac arrest)

Dosage Adjustments

• No dose adjustments are required for patients with renal or hepatic dysfunction.

Side Effects

Common Side Effects:

• Injection site reactions (pain, swelling, redness)
• Headache
• Fever
• Fatigue
• Nausea
• Muscle or joint pain

Rare but Serious Side Effects:

• Severe allergic reaction (anaphylaxis)
• Syncope (fainting), sometimes accompanied by tonic-clonic movements.

Long-Term Effects: No significant long-term adverse effects have been reported.

Adverse Drug Reactions (ADR): Anaphylaxis is a rare but significant ADR that warrants immediate medical intervention.

Contraindications

• History of severe allergic reaction (anaphylaxis) to any component of the vaccine, including yeast.

Drug Interactions

• Can be co-administered with other vaccines, but should be administered with separate syringes at different injection sites.
• No significant interactions with commonly prescribed medications, OTC drugs, or food.

Pregnancy and Breastfeeding

• Pregnancy Safety Category: Not recommended during pregnancy, although data suggest no increased risk to the fetus. If pregnancy occurs during vaccination, the remaining doses should be delayed until after delivery.

• Breastfeeding: Can be used during breastfeeding. No adverse effects on breastfed infants have been reported.

Drug Profile Summary

• Mechanism of Action: Induces neutralizing antibodies against HPV types 6, 11, 16, and 18, preventing infection.
• Side Effects: Commonly injection-site reactions, headache, fever. Rarely, anaphylaxis or syncope.
• Contraindications: Hypersensitivity to any vaccine component.
• Drug Interactions: Minimal.
• Pregnancy & Breastfeeding: Not recommended during pregnancy but safe during breastfeeding.
• Dosage: Adults (15-45 years): 3 doses (0, 2, and 6 months). Children (9-14 years): 2 doses (0 and 6-12 months).
• Monitoring Parameters: Observe for immediate allergic reactions after administration.

Popular Combinations

• Can be administered concomitantly with other vaccines, such as Tdap, Hepatitis A, Hepatitis B, and meningococcal vaccines.

Precautions

• Screen for contraindications (e.g., previous hypersensitivity to HPV vaccine).
• Observe for 15 minutes post-vaccination for syncope.
• No pregnancy testing is required before vaccination.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Human Papillomavirus Quadrivalent Vaccine, Recombinant?

A: Adults (15-45): 0.5ml IM at 0, 2, and 6 months. Children (9-14): 0.5ml IM at 0 and 6-12 months.

Q2: Can the vaccine be administered during pregnancy?

A: Not routinely recommended, but data suggests no increased risk to the fetus. Postpone remaining doses until after delivery if pregnancy occurs.

Q3: Is it safe to give the HPV vaccine while breastfeeding?

A: Yes, it is considered safe to administer the HPV vaccine during breastfeeding.

Q4: What are the most common side effects of the vaccine?

A: Injection site reactions (pain, redness, swelling), headache, fever, fatigue are common.

Q5: Who should not receive this vaccine?

A: Individuals with a history of severe allergic reaction (anaphylaxis) to any component of the vaccine, including yeast, should not receive it.

Q6: What is the mechanism of action of the HPV quadrivalent vaccine?

A: It works by stimulating the immune system to produce antibodies against HPV types 6, 11, 16, and 18. These antibodies prevent infection by these HPV types.

Q7: Does the HPV vaccine treat existing HPV infections or related diseases?

A: No, the vaccine is strictly preventative. It does not treat pre-existing HPV infections or related diseases.

Q8: What should be done if a patient faints after receiving the vaccine?

A: Patients should be observed for 15 minutes following administration. If syncope occurs, ensure the patient is in a supine position or Trendelenburg position and monitor until recovery.

Q9: Can HPV vaccines be given at the same time as other vaccines?

A: Yes, but they should be administered with separate syringes at different injection sites.