BACKGROUND: Steep increases in herpes zoster (HZ) incidence, hospitalization due 
to HZ and the risk of post-herpetic neuralgia as a complication of HZ occur in 
people over 50 years of age. Two HZ vaccines are currently authorized for use in 
those 50 years of age and older in Canada: a live attenuated zoster vaccine 
(LZV) authorized in 2008; and a recombinant subunit vaccine (RZV) authorized in 
October 2017.
OBJECTIVES: To review current evidence and develop guidance on whether the 
previously authorized LZV (Zostavax®) and/or the recently authorized RZV 
(Shingrix®) vaccine should be offered to Canadians 50 years of age and older: 1) 
at a population-level, in publicly funded immunization programs; and 2) at an 
individual-level, to individuals wishing to prevent HZ, or by clinicians wishing 
to advise individual patients about preventing HZ.
METHODS: The National Advisory Committee on Immunization (NACI) Herpes Zoster 
Working Group developed a predefined search strategy to identify all eligible 
studies, assessed their quality, and summarized and analyzed the findings. A 
Cost Utility Analysis of LZV and RZV was also conducted from a health care 
system perspective. Recommendations were proposed according to NACI's 
evidence-based process. The strength of these recommendations was defined, and 
the Grade of evidence supporting them was identified. In light of the evidence, 
the recommendations were then considered and approved by NACI.
RESULTS: Five recommendations were developed for public health and 
individual-level decision-making. 1) RZV should be offered to 
populations/individuals >50 years of age without contraindications (Strong NACI 
Recommendation, Grade A evidence). 2) RZV should be offered to 
populations/individuals >50 years of age without contraindications who have 
previously been vaccinated with LZV (Strong NACI Recommendation, Grade A 
evidence). Re-immunization with two doses of RZV may be considered one year 
after LZV (Discretionary NACI Recommendation, Grade I evidence). 3) RZV should 
be offered to populations/individuals >50 years of age without contraindications 
who have had a previous episode of HZ (Strong NACI Recommendation, Grade B 
evidence). Immunization with two doses of RZV may be considered one year after 
the HZ episode (Discretionary NACI Recommendation, Grade I evidence). 4) LZV may 
be considered for immunocompetent populations/individuals >50 years of age 
without contraindications when RZV is contraindicated, unavailable or 
inaccessible (Discretionary NACI Recommendation, Grade A evidence). 5) RZV (not 
LZV) may be considered in immunocompromised adults >50 years of age on a 
case-by-case basis (Discretionary NACI Recommendation, Grade I evidence).
CONCLUSION: Both vaccines have been shown to be safe and immunogenic and to 
reduce the incidence of HZ and post-herpetic neuralgia. Vaccine efficacy of LZV 
against HZ decreases with age at, and time since vaccination. The vaccine 
efficacy of RZV remains higher and appears to decline more slowly than vaccine 
efficacy of LZV across all age groups. Both vaccines are cost-effective in those 
50 years of age and older compared with no vaccination, especially in those 
65-79 years of age. RZV is more cost-effective than LZV.