January 2020

Shingles, is a reactivation of latent varicella zoster virus (VZV). Risk of hospitalization increases with age. Complications include post-herpetic neuralgia and herpes zoster ophthalmicus.

Vaccines

Administration Zostavax®II  (LZV) Shingrix® (RZV)
vaccine type live attenuated vaccine recombinant subunit vaccine
route subcutaneous intramuscular
dose one dose two doses (two months apart)
age ≥ 50 years ≥ 50 years
contraindications immunosuppression, hypersensitivity hypersensitivity
funding publicly-funded 65-70 years private purchase

Both vaccines have been shown to be safe, immunogenic, and reduce the incidence of HZ and post-herpetic neuralgia. For more information refer to the Canadian National Advisory Committee of Immunization (NACI) recommendations.

NACI Recommendations

RZV (Shingrix®), should be offered to individuals >50 years of age without contraindications including:

  • patients previously vaccinated with LZV. Re-vaccinate with two doses of RZV at least one year after receiving LZV.
  • patients with a previous episode of herpes zoster disease. Provide two doses of RZV at least one year after herpes zoster episode.
  • immunocompromised patients may be considered on a case-by-case assessment of the benefits vs risks.

Note:

  • LZV may be considered for immunocompetent individuals >50 years of age without contraindications when RZV is contraindicated, unavailable or inaccessible.
  • Vaccine efficacy against HZ decreases with age and over time since vaccination with LZV.
  • Vaccine efficacy against HZ remains higher and appears to decline more slowly in all age groups with RZV.

Concomitant Administration

In general, live and inactivated vaccines may be administered at the same time as other parental vaccines. Herpes Zoster vaccines may be given at the same time as unadjuvanted seasonal influenza vaccine.


Questions from Health Care Providers

Below address the vaccine questions put forward by participants at the November Vaccine Hesitancy Continuing Medical Education Event.

Right now only LZV (Zostavax® II) is publicly funded for adults 65 to 70-year-olds.

The recommendations from NACI are that herpes zoster vaccine be given to adults 50 years of age and older, and to wait one year if there was a recent episode of shingles. There is no recommendation to give healthy adults younger than 50 years a herpes zoster vaccine. The risk of herpes zoster disease increases with age.

Low dose immunosuppressives are defined by NACI as:

  • low dose prednisone (<20 mg/day)
  • methotrexate ≤0.4 mg/kg/week, azathioprine ≤ 3.0 mg/kg/day
  • 6-mercaptopurine ≤1.5 mg/kg/day

Immunosuppressive medications that are provided at a low dose are called low-dose immunosuppressives. Refer to NACI’s Tables 1 and 2 for a list of immunosuppressives.

There is a risk of recurrence of herpes zoster, which is why vaccination is still considered even if someone has had an episode, regardless of where the episode was.

NACI states: “For adults ≥50 years of age without contraindications who have had a previous episode of HZ, immunization with a two-dose series of RZV should be offered. Immunization with RZV may be considered at least one year after the episode of HZ. Persons with active HZ should not be immunized with HZ vaccine.”

Zostavax® II is a one-dose schedule. It is a live virus vaccine. The vaccine is not licensed, nor are there recommendations, for a booster dose of LZV. If someone has received LZV, they can consider receiving two doses of RZV.

Shingrix® is not routinely recommended for immunocompromised individuals. NACI states:

“Individuals who are immunocompromised, either due to underlying conditions or immunosuppressive agents, have an increased risk of developing HZ. They may be more likely to experience HZ recurrence, atypical and/or more severe disease and complications. RZV should be considered based on a case-by-case assessment of benefits vs risks. When indicated, it should be administered before initiating immunosuppressive treatment that might lead to immunodeficiency. It is recommended that RZV be administered at least 14 days before the treatment.”

NACI does state, “RZV should be administered to individuals for whom vaccine is indicated regardless of whether the person has a history of varicella infection. Nearly all Canadians eligible for HZ immunization will have had prior varicella exposure, even if a diagnosis of varicella cannot be recalled. There is no known safety risk associated with immunization of healthy individuals who are susceptible to VZV.

If an individual is certain they have never had chickenpox, a test of immunity can be done to determine if the individual really did not ever have chickenpox infection, in which case herpes zoster vaccines are not required, though such a patient is at risk for primary chickenpox infection.