Herpes Zoster / Shingles Vaccine

Usage

• This vaccine is prescribed for the prevention of herpes zoster (shingles) and its associated complications.
• Pharmacological classification: Vaccine.
• It works by stimulating the immune system to produce antibodies against the varicella-zoster virus (VZV), the virus that causes chickenpox and shingles. This boosts immunity, reducing the risk of VZV reactivation and the development of shingles.

Alternate Names

• Zoster vaccine recombinant, Shingles vaccine.
• Brand name: Shingrix.

How It Works

• Pharmacodynamics: The vaccine contains a noninfectious recombinant VZV glycoprotein E antigen combined with an adjuvant system (AS01B) to enhance the immune response. Upon administration, the vaccine triggers a targeted immune response against VZV glycoprotein E. This leads to the production of antibodies and specific T-cells which provide long-lasting protection against shingles.
• Pharmacokinetics: The vaccine is administered intramuscularly. The specific pharmacokinetic parameters (absorption, distribution, metabolism, elimination) of the recombinant VZV glycoprotein E antigen have not been extensively studied. The adjuvant system is known to be locally absorbed at the injection site. No specific enzyme pathways or receptor interactions for either the antigen or adjuvant have been characterized for this vaccine. Elimination pathways have not been specifically studied for this vaccine.

Dosage

Standard Dosage

Adults (50 years and older):

• 0.5 mL intramuscularly administered in two doses, 2 to 6 months apart.

Adults (19 years and older) Immunocompromised:

• 0.5 mL intramuscularly administered in two doses, 1 to 2 months apart.

Children:

• Not recommended for children under 18 years of age.

Special Cases:

• Elderly Patients: Standard adult dosing.
• Patients with Renal Impairment: No dose adjustment required.
• Patients with Hepatic Dysfunction: No dose adjustment required.
• Patients with Comorbid Conditions: No specific dose adjustments indicated. However, consider individual patient health status and consult specialized guidelines if necessary.

Clinical Use Cases

Shingrix is exclusively indicated for the prevention of herpes zoster. It has no role in clinical scenarios such as intubation, surgical procedures, mechanical ventilation, ICU use, or emergency situations.

Dosage Adjustments

No specific dose adjustments are required based on patient-specific factors except for age and immunocompromised status as noted above.

Side Effects

Common Side Effects:

• Pain, redness, and swelling at the injection site.
• Myalgia, fatigue, headache, shivering, fever, gastrointestinal symptoms.

Rare but Serious Side Effects:

• Severe allergic reactions (anaphylaxis).

Long-Term Effects:

• No long-term adverse effects have been reported.

Adverse Drug Reactions (ADR):

• Anaphylaxis.

Contraindications

• Hypersensitivity to any component of the vaccine.

Drug Interactions

• No clinically significant drug interactions have been identified. The vaccine can be administered concurrently with other vaccines. However, it is generally recommended to administer Shingrix at a separate injection site.

Pregnancy and Breastfeeding

• The safety of Shingrix during pregnancy and breastfeeding has not been established. Its use should be considered only when the potential benefits outweigh the potential risks.

Drug Profile Summary

• Mechanism of Action: Stimulates an immune response against varicella-zoster virus.
• Side Effects: Injection site reactions, myalgia, fatigue, headache, fever, gastrointestinal symptoms. Rarely, anaphylaxis.
• Contraindications: Hypersensitivity to any component of the vaccine.
• Drug Interactions: No significant drug interactions.
• Pregnancy & Breastfeeding: Safety not established.
• Dosage: Adults ≥50 years: 0.5 mL IM x 2 doses, 2-6 months apart. Adults ≥19 years, Immunocompromised: 0.5 mL IM x 2 doses, 1-2 months apart.
• Monitoring Parameters: Observe for injection site reactions and systemic symptoms.

Popular Combinations

• Shingrix can be administered concomitantly with other vaccines, such as the influenza vaccine and pneumococcal vaccine, but at separate sites.

Precautions

• General Precautions: Standard vaccine administration precautions. Screen for contraindications and allergies.
• Specific Populations:
  • Pregnant Women: Safety not established. Use only if potential benefits outweigh potential risks.
  • Breastfeeding Mothers: Safety not established. Use only if potential benefits outweigh potential risks.
  • Children & Elderly: Not recommended for individuals younger than 18 years. Standard adult dosing for older adults.
• Lifestyle Considerations: No specific lifestyle considerations.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Herpes Zoster / Shingles Vaccine?

A: For adults 50 years and older, two doses of 0.5 mL are administered intramuscularly, 2 to 6 months apart. For immunocompromised adults 19 years and older, the same dose is given 1 to 2 months apart.

Q2: Can Shingrix be given to someone who has already had shingles?

A: Yes, Shingrix is recommended even for individuals with a prior history of shingles.

Q3: Can Shingrix be given with other vaccines?

A: Yes, Shingrix can be administered concurrently with other vaccines, but at a separate injection site.

Q4: What are the common side effects of Shingrix?

A: Common side effects include pain, redness, and swelling at the injection site, as well as myalgia, fatigue, headache, shivering, fever, and gastrointestinal symptoms.

Q5: Is Shingrix a live vaccine?

A: No, Shingrix is a recombinant, non-live vaccine.

Q6: Who should not receive Shingrix?

A: Individuals with a history of severe allergic reaction to any component of the vaccine should not receive Shingrix.

Q7: How effective is Shingrix?

A: Shingrix is over 90% effective at preventing shingles and postherpetic neuralgia.

Q8: How long does the protection from Shingrix last?

A: Current evidence suggests the protection from Shingrix lasts at least several years. Long-term follow up continues to evaluate duration of protection.

Q9: Can Shingrix prevent chickenpox?

A: No, Shingrix is not indicated for the prevention of chickenpox (primary varicella infection).

Q10: When should the Shingrix vaccine be administered to immunocompromised patients?

A: Immunocompromised patients aged 19 and older should receive two doses, 1-2 months apart. Ideally, it should be administered at least 14 days before the initiation of immunosuppressive therapy, although waiting a month is preferred if feasible.