Herpes Zoster (Shingles)

Key Information

• Disease: Primary varicella-zoster virus infection causes varicella (chickenpox); reactivation results in herpes zoster (shingles), characterized by neuropathic pain and a dermatomal vesicular rash.
• Complications: The most frequent is post-herpetic neuralgia (PHN), which can be debilitating.
• Vaccine: Shingrix® (Recombinant Zoster Vaccine, RZV) is the only vaccine currently authorized for use in Canada. The live-attenuated zoster vaccine (LZV) was discontinued in 2023.

Recommendations for Use

• Adults ≥50 Years:
  • RZV is recommended for the prevention of HZ and PHN.
  • Individuals who previously received LZV or had a previous episode of HZ should receive RZV after at least one year.
  • Consider RZV for immunocompromised adults on a case-by-case basis.
• Immunocompromised Persons:
  • Increased risk of developing HZ; RZV should be considered before starting immunosuppressive treatment.

Vaccine Administration

• Dosage: 0.5 mL intramuscularly, with two doses administered 2 to 6 months apart.
• Storage: Refrigerate at +2°C to +8°C; protect from light.

Safety and Adverse Events

• Common Reactions: Injection site reactions (pain, redness), systemic reactions (fatigue, myalgia, headache).
• Rare Reactions: Serious adverse events are very rare. No significant long-term safety concerns noted.

Immunogenicity, Efficacy, and Effectiveness

• Efficacy: RZV maintains over 90% efficacy in preventing HZ and PHN in all age groups ≥50 years for at least 4 years post-immunization.
• Immunogenicity: Robust and persistent antibody response observed up to 9 years post-immunization.