Introduction
Shingrix (recombinant zoster vaccine) is a non-live, recombinant subunit vaccine approved by the FDA in 2017 for the prevention of herpes zoster (shingles) in adults. Developed by GlaxoSmithKline, it represents a significant advancement over the previously available live-attenuated zoster vaccine (Zostavax), offering superior and longer-lasting protection against shingles and its complications.
Mechanism of Action
Shingrix contains recombinant glycoprotein E (gE) antigen from the varicella-zoster virus (VZV) combined with AS01B adjuvant system. The vaccine works by stimulating both humoral and cell-mediated immune responses. The AS01B adjuvant system enhances the immune response by activating antigen-presenting cells and promoting CD4+ T-cell proliferation. This results in robust VZV-specific memory B-cell and T-cell responses that provide protection against herpes zoster reactivation.
Indications
- Prevention of herpes zoster (shingles) in adults aged 50 years and older
- Prevention of herpes zoster in adults aged 18 years and older who are or will be at increased risk of shingles due to immunodeficiency or immunosuppression caused by known disease or therapy
Dosage and Administration
- Standard dosing: 0.5 mL administered intramuscularly (preferably in the deltoid region)
- Schedule: Two-dose series administered 2-6 months apart
- Special populations:
- Immunocompromised patients: May receive the second dose 1-2 months after the first dose - Patients who previously received Zostavax: Should still receive Shingrix series - No dosage adjustment required for renal or hepatic impairment
Pharmacokinetics
- Absorption: Administered intramuscularly; antigen is processed through normal immune pathways
- Distribution: Vaccine components remain localized at injection site with minimal systemic distribution
- Metabolism: Degraded via normal protein catabolic pathways
- Elimination: Cleared through normal metabolic processes
- The vaccine's effectiveness is mediated through immune memory rather than traditional pharmacokinetic parameters
Contraindications
- History of severe allergic reaction (e.g., anaphylaxis) to any component of the vaccine
- Known hypersensitivity to the AS01B adjuvant system or any vaccine component
Warnings and Precautions
- Syncope has been reported following vaccination; observe patients for 15 minutes post-administration
- Moderate or severe acute illness: Consider deferring vaccination until symptoms improve
- Guillain-Barré syndrome has been reported in some vaccine recipients (unknown if causal)
- Immunocompromised patients: May have reduced immune response
- Pregnancy: No human data available; use only if potential benefits justify potential risk
- Breastfeeding: Unknown if vaccine components are excreted in human milk
Drug Interactions
- Immunosuppressive therapy: May diminish immune response to Shingrix
- Concurrent administration with other vaccines: May be administered simultaneously with other age-appropriate vaccines at different injection sites
- Antiviral medications: No known interactions, but theoretical concern with live vaccines (not applicable to Shingrix as it is non-live)
Adverse Effects
- Very common (>10%):
- Injection site reactions (pain, redness, swelling) - Myalgia - Fatigue - Headache - Shivering - Fever - Gastrointestinal symptoms
- Common (1-10%):
- Injection site pruritus - Arthralgia
- Serious but rare:
- Guillain-Barré syndrome (reported in some cases) - Severe allergic reactions
Monitoring Parameters
- Local injection site reactions for 2-3 days post-vaccination
- Systemic symptoms (fever, fatigue, myalgia) for 2-3 days
- Document vaccine administration details (date, site, lot number)
- For immunocompromised patients: Consider assessing immune response in specific high-risk situations
Patient Education
- Expect local reactions (pain, redness, swelling at injection site) and systemic symptoms (fatigue, muscle pain, headache, fever)
- These reactions are common and typically resolve within 2-3 days
- Use cool compresses and analgesics (acetaminophen or NSAIDs) for symptom management
- Complete the two-dose series for optimal protection
- Even if you've had shingles before or received Zostavax, you should still receive Shingrix
- Report severe or persistent reactions to healthcare provider
- Protection persists for at least 7 years (ongoing studies evaluating longer duration)
References
1. FDA prescribing information: Shingrix (zoster vaccine recombinant, adjuvanted) 2. Cunningham AL, et al. Efficacy of the herpes zoster subunit vaccine in adults 70 years of age or older. N Engl J Med. 2016;375(11):1019-1032. 3. Lal H, et al. Efficacy of an adjuvanted herpes zoster subunit vaccine in older adults. N Engl J Med. 2015;372(22):2087-2096. 4. Centers for Disease Control and Prevention. Prevention of Herpes Zoster: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2018;67(3):1-37. 5. Anderson TC, et al. Use of Recombinant Zoster Vaccine in Immunocompromised Adults Aged ≥19 Years: Recommendations of the Advisory Committee on Immunization Practices - United States, 2022. MMWR Morb Mortal Wkly Rep. 2022;71(3):80-84. 6. GSK clinical trial data: ZOE-50 and ZOE-70 studies