For additional information, refer to the National Advisory Committee on Immunization (NACI) Statement on the recommended use of herpes zoster vaccine and Update on the use of herpes zoster vaccine.
Significant revisions since the last chapter update are highlighted in the CIG Summary Table of Changes available on the PHAC website.
Herpes zoster (shingles) is a manifestation of reactivation of the varicella zoster virus (VZV), a DNA virus of the Herpesvirus family, which, as a primary infection, causes varicella (chickenpox).
VZV can be spread from a person with HZ to an individual that has never had varicella by direct contact with skin lesions. Less commonly, VZV can be spread by the airborne route if the person has disseminated HZ. Less frequently, transmission can occur from fomites, such as articles freshly soiled by discharges from vesicles or, in the case of disseminated HZ, mucous membrane secretions. The person who acquires VZV through these routes will develop varicella (chickenpox). The incubation period is from 10 to 21 days, usually in the range of 14 to 16 days. HZ is less likely to result in transmission of VZV than varicella. Persons with HZ are infectious until all lesions are crusted over.
Any person who has had varicella is at risk of developing HZ; however, HZ occurs most frequently among older adults and immunocompromised persons. Age is the most important risk factor for development of HZ and two-thirds of the cases occur in individuals over 50 years of age. This age-related risk may be explained by both waning immunity over time following the initial varicella infection, and the loss of components of VZV-specific cell mediated immunity as a result of natural aging processes. The severity of illness associated with HZ and its complications also increases markedly with age. Up to 10% of person over 65 years of age will be admitted to hospital with an episode of HZ. Recent studies have shown that the widespread use of varicella vaccine has not impacted the incidence of HZ.
Spectrum of clinical illness
VZV causes two distinct clinical syndromes: primary infection (varicella, also called chickenpox) and reactivation of latent infection (HZ, also called shingles). Following varicella, VZV establishes latency in the sensory nerve ganglia, and may reactivate later as HZ.
HZ infection is characterized by pain and a unilateral vesicular eruption, usually in a single dermatome. Complications of acute HZ are potentially severe and may include sight-threatening eye infections, central nervous system infection, nerve palsies including the Ramsay-Hunt Syndrome, neuromuscular disease including Guillain-Barré Syndrome, and secondary bacterial infections. The most frequent complication of acute HZ is post-herpetic neuralgia (PHN) which is characterized by prolonged and often debilitating neurogenic pain that persists for more than 90 days from the onset of rash. This complication occurs in approximately 20% of adults with HZ and in one-third or more of octogenarians and often has a major adverse impact on quality of life, especially in elderly persons. Treatment options for PHN are of limited effectiveness. The risk of mortality from VZV-associated disease is low.
Globally, the incidence of HZ ranges from 1.2 to 3.4 cases per 1,000 healthy persons per year, increasing to 3.9 to 11.8 cases per 1,000 individuals per year among those over 65 years of age. HZ-associated hospitalization rates vary across countries and are estimated to range from 5 to 10 per 100,000 people for an average length of stay of 10 to 13 days.
In recent studies, the lifetime risk of HZ has been estimated to be as high as 30% in the general population. In Canada, it is estimated that each year there are 130,000 new cases of HZ, 17,000 cases of PHN and 20 deaths, which result in 252,000 physician consultations and 2,000 hospitalizations.
The relationship between the introduction of routine childhood varicella immunization programs and the incidence of HZ in adults is unclear. It had been hypothesized that implementation of childhood varicella immunization programs might decrease natural immune boosting of older persons from circulating wild-type VZV and thereby increase the risk of VZV reactivation. However, different jurisdictions have reported increases and decreases in the incidence of HZ over time, and it is likely that multiple other factors contribute to variations in the incidence of HZ including modifications to reporting or diagnostic coding of cases or changes in risk factors.
For complete prescribing information, consult the product leaflet or information contained within the product monograph available through Health Canada’s Drug Product Database. Refer to Contents of Vaccines Available for Use in Canada in Part 1 for a list of vaccines available for use in Canada and their contents.
The incidence of HZ and PHN, as well as the duration and severity of HZ were significantly reduced in HZ vaccine recipients in a large clinical trial of people 60 years of age and older. Overall vaccine efficacy was 51.3% for HZ incidence and 66.5% for PHN. Subsequent studies in people aged 50 to 59 years showed HZ vaccine to be safe, immunogenic and effective in this population as well. Vaccine protection against HZ remains statistically significant up to 5 years and results also suggest some efficacy up to year 7.
The immune correlates of protection from HZ among individuals previously infected with varicella are not well established, and none have been accepted as markers of protection. A clinical trial has demonstrated that HZ vaccine elicited higher VZV-specific immune responses at 6 weeks post-vaccination than placebo. Vaccine-related immune responses declined significantly over the subsequent year, then remained relatively stable for the following two years.
Adults (60 years of age and older)
One dose of HZ vaccine is recommended for persons without contraindications 60 years of age and older for the prevention of HZ and PHN. HZ vaccine is not intended for the prevention of varicella or for the treatment of HZ or PHN.
Adults (50 to 59 years of age)
HZ vaccine may be used in adults aged 50 to 59 years of age without contraindications. The incidence and severity of HZ begins to increase with age after 50 years. While all adults aged 50 and older receive some benefit, the duration of protection is unknown beyond 7 years, and it is uncertain whether vaccination in this age group will provide ongoing protection at older ages when the incidence of HZ is higher.
Adults with a history of herpes zoster disease
HZ disease may recur in individuals who have previously had one or more episodes of HZ disease. Vaccinated individuals may have lower recurrence rates as shown in one study. Other studies have shown that administration of HZ vaccine to individuals with a prior history of HZ disease is safe. Based on these findings and favourable immunogenicity studies, HZ vaccine may be administered to individuals 50 years of age and older with a prior history of HZ disease. Based on expert opinion, there should be an interval of at least one year between an episode of HZ and receipt of HZ vaccine. Persons with active HZ should not be immunized with HZ vaccine.
Adults with a history of herpes zoster ophthalmicus
There are few reports of recurrent HZ ophthalmicus (HZO) in patients who have a history of HZO and subsequently receive HZ vaccine. NACI has reviewed these reports but causality has been difficult to determine, since HZO may recur at any time. Therefore, if considering immunization of individuals with a history of HZO, it is important to discuss these cases with an ophthalmologist and to ensure that patients with a history of HZO no longer have active disease. Patients with a history of HZO should be informed by their healthcare provider that cases of recurrent HZO following vaccine have occurred, although causality has not been established, and that the risk of recurrent HZO relative to the potential benefit of preventing future recurrences is unknown. Refer to Less common and serious or severe adverse events.
Adults with or without a history of varicella or documented prior varicella infection
HZ vaccine should be administered to individuals indicated for vaccine regardless of whether or not the person has a history of varicella infection. Given that nearly all Canadians eligible for HZ immunization will have had prior varicella exposure, even if a diagnosis of varicella cannot be recalled, routine testing of adults aged 50 years and older for VZV antibody prior to immunization is not recommended. There is no known safety risk associated with vaccination of healthy individuals who are susceptible to VZV. In the rare circumstance that an adult aged 50 years and older is known to be serologically susceptible to VZV, based on previous testing for another reason, the individual should be vaccinated with two doses of univalent varicella vaccine rather than HZ vaccine.
HZ vaccine is not normally indicated for women of childbearing potential but, as a live vaccine, it is contraindicated during pregnancy. It is recommended that women avoid pregnancy for at least 4 weeks after receipt of HZ vaccine. It is not known whether HZ vaccine virus is secreted in human milk. Given the age indication for HZ vaccine, pregnant or breastfeeding women are unlikely among the target population. Refer to Immunization in Pregnancy and Breastfeeding in Part 3 for additional general information.
Residents of long-term care facilities should receive all routine immunizations appropriate for their age and risk factors, including HZ vaccine. Refer to Immunization of Patients in Health Care Institutions in Part 3 for additional general information.
In general, immunocompromised persons should not receive live vaccines because of the risk of disease caused by the vaccine strain. There is some evidence, however, that HZ disease may occur more frequently in immunocompromised persons compared with immunocompetent persons. One study found a statistically significant increase in the incidence of HZ recurrence in immunocompromised persons of 12% compared to 5.7% in immunocompetent persons at 8 years after the initial HZ episode. Literature suggests that HZ vaccine may be safely administered to individuals on low-dose immunosuppression. Given the higher burden of illness in immunocompromised persons, the safety and efficacy of HZ vaccine in this population is an important area of ongoing research. Refer to Immunosuppressive therapy.
When considering immunization of an immunocompromised person, approval from the individual’s attending physician should be obtained before vaccination. For complex cases, referral to a physician with expertise in immunization or immunodeficiency is advised.
Congenital (primary) immunodeficiency
All live vaccines, including HZ vaccine, are contraindicated in people with defects in T cell function (e.g., T cell, natural killer cell, and combined cellular and antibody defects). Persons with isolated immunoglobulin deficiency, phagocytic defects (e.g., chronic granulomatous disease), complement deficiency, and neutrophil disorders (e.g., neutropenia, Chediak-Higashi syndrome) may be vaccinated with HZ vaccine.
Acquired (secondary) immunodeficiency
Malignant hematologic disorders
HZ vaccine is contraindicated in individuals with severe immunodeficiency due to conditions such as: blood dyscrasias, lymphomas, or other malignant neoplasms affecting the bone marrow or lymphatic systems. HZ vaccine is contraindicated in people with immunodeficiency due to acute or chronic leukemia. However, persons with leukemia in remission and who have not received immunosuppressive chemotherapy or radiation for at least 3 months and who do not have defects in T cell function can receive HZ vaccine; consultation with an immunologist may be required.
Malignant solid tumours
HZ vaccine is contraindicated in people undergoing immunosuppressive treatment for any malignant solid tumours.
Hematopoietic stem cell transplantation (HSCT) - autologous or allogeneic
Solid organ transplantation
HZ vaccine should not be given after solid organ transplantation.
Vaccination status for HZ should be reviewed for immunocompetent persons aged 50 years and older who might be anticipating initiation of immunosuppressive treatments or who have diseases that might lead to immunodeficiency.
If indicated, HZ vaccine should be administered at least 4 weeks before the initiation of immunosuppressive therapy (e.g. 20 mg/day or more of prednisone or its equivalent for an adult for 14 days or more; chemotherapy; extensive radiation therapy; cyclosporine; cyclophosphamide). If vaccine cannot be given in this time frame before immunosuppressive therapy, a period of at least 3 months should elapse after immunosuppressive drugs (except high-dose systemic corticosteroids) have been stopped before administration of live vaccines. A period of at least 4 weeks should elapse between discontinuation of high-dose systemic steroids and the administration of live vaccines. The interval between discontinuation of immunosuppressive drugs and HZ vaccine administration may vary with the intensity of the immunosuppressive therapy, underlying disease and other factors.
Unlike other live vaccines, HZ vaccine is not used for eliciting a primary immune response and most persons receiving this vaccine have prior immunity to varicella. Therefore, it is reasonable to consider HZ vaccine in people receiving low dose immunuosuppressive therapy as follows:
Retrospective data also demonstrate the safety of HZ vaccine in people receiving anti-TNF biologics (TNF-alpha antagonists and TNF-receptor blockers) for inflammatory conditions. The risk associated with HZ vaccine may increase if people who are also receiving other immunosuppressive agents such corticosteroid therapy. It is reasonable to consider HZ vaccine in patients receiving anti-TNF biologics on a case by case basis after review with an expert in immunodeficiency.
Corticosteroid therapy is not a contraindication to administering a live vaccine when steroid therapy is short-term (i.e., less than 14 days); or a low-to-moderate dose (less than 20 mg of prednisone or equivalent per day for an adult); or long-term, alternate-day treatment with short-acting preparations; or maintenance physiologic replacement therapy; or administered topically, inhaled, or locally injected (e.g., joint injection).
A specialist in HIV infection/immunologist should be consulted for advice on HZ immunization in HIV-infected people. HZ vaccine is contraindicated in persons with advanced HIV/AIDS.
Refer to Contraindications and Precautions. Refer to Immunization of Immunocompromised Persons in Part 3 for additional general information.
Although definitive data are lacking, individuals with autoimmune disease not being treated with immunosuppressive drugs are not considered significantly immunocompromised and should receive HZ immunization following consultation with a physician. Rheumatic disease modifying agents such as hydroxychloroquine, sulfasalazine, or auranofin are not considered immunosuppressive. The nature of the person’s underlying disease should be considered. HZ vaccine may be considered in persons on low doses of immunosuppressive agents. Refer to Immunosuppressive therapy for additional information.
Refer to Immunization of Persons with Chronic Diseases in Part 3 for additional general information.
Workers are not at increased risk of developing HZ because HZ is due to reactivation of a latent VZV infection. However, it is important to promote varicella (chickenpox) immunization with those who are at occupational risk of exposure or transmission to high risk individuals. Refer to Varicella (Chickenpox) Vaccine in Part 4 for more specific information and to Immunization of Workers in Part 3 for additional general information.
HZ vaccine is not indicated for post-exposure management of individuals susceptible to varicella. Refer to Post-exposure immunization in Varicella (Chickenpox) Vaccine in Part 4 for appropriate management of individuals who are susceptible to varicella following close contact with a person with HZ.
Close contact to a person with HZ includes:
Refer to Passive Immunizating Agents in Part 5 for additional general information.
Each dose is 0.65 mL (the entire contents of the reconstituted vial).
Route of administration
HZ vaccine should be administered subcutaneously. Refer to Vaccine Administration Practices in Part 1 for additional information.
Persons, 60 years of age and older without contraindications, should receive one dose of HZ vaccine. Adults 50 to59to 59 years of age without contraindications may receive one dose of HZ vaccine.
There is no current recommendation for booster doses of HZ vaccine. The efficacy of protection has not been assessed beyond 7 years and it is not known whether booster doses of vaccine are beneficial. This is an area of ongoing research.
Serologic testing is not recommended before or after receiving HZ vaccine. There is no known safety risk associated with HZ vaccination of healthy individuals who are VZV susceptible. In the rare circumstance that an adult aged 50 years and older is known to be susceptible to VZV, based on previous serological testing for another reason, the individual should be vaccinated with two doses of univalent varicella vaccine rather than HZ vaccine.
HZ vaccine should be stored frozen at -15°C or colder. Diluent should be stored at room temperature (+20°C to +25°C) or in the refrigerator (+2°C to +8°C) and should not be frozen. Before reconstitution, the vaccine should be protected from light. Refer to Storage and Handling of Immunizing Agents in Part 1 for additional general information.
In general, HZ vaccine may be administered concomitantly with other live vaccines given by the parenteral, oral, or intranasal routes. For concomitant parenteral injections, different injection sites and separate needles and syringes should be used. HZ vaccine may be given at any time before or after live oral or intranasal vaccines. If two live parenteral vaccines are not administered concomitantly, there should be a period of at least 4 weeks before the second live parenteral vaccine is given.
Concomitant administration of pneumococcal 23-valent polysaccharide vaccine (Pneu-P-23) and HZ vaccine has not resulted in decreased efficacy and so the two vaccines can be given concomitantly.
Refer to Timing of Vaccine Administration in Part 1 for additional general information.
Refer to Vaccine Safety in Part 2 for additional general information.
HZ vaccine has been evaluated for safety in the large placebo-controlled Shingles Prevention Study (SPS) that included a subgroup followed closely for adverse events. Reactions were usually mild and included injection site pain, swelling or redness in up to 48.3% of recipients, compared to 16.6% in placebo recipients. Most reactions resolved within 4 days. The rate was higher in recipients aged 60 to 69 years than those over 70 years of age. Less serious systemic adverse events, such as headache, were more common in vaccine recipients (6.3% versus 4.9%).
In the SPS study, a varicella-like rash occurred at the injection site in 0.11% of vaccinees (0.04% in placebo recipients) and lasted between 5 and 6 days, but varicella-like rashes elsewhere were similar in the two groups and lasted longer in both. In an earlier study, vaccine strain virus had been rarely identified in specimens of lesions from subjects who reported varicella-like rashes, but none were found in the SPS.
In the SPS, there were no clinically significant differences in serious adverse events between the vaccine and placebo groups. Overall and HZ–related rates of hospitalization were similar between the vaccine and placebo groups. There was no overall difference in observed deaths in the HZ vaccinated group as compared to the placebo group.
The safety and tolerability of a second dose of HZ vaccine administered 42 days following the initial dose was evaluated in a clinical trial of 98 adults. The frequency of adverse events after the second dose was generally similar to that seen with the first dose.
Recurrence or exacerbation of herpes zoster ophthalmicus (HZO) has been reported in several cases world-wide following HZ vaccination in people with a history of HZO. Following a causality assessment of seven cases of HZO which were temporally associated with the administration of HZ vaccine, NACI concluded that there was insufficient evidence to recommend for or against the administration of HZ vaccine in individuals with a history of HZO. More evidence is required for further assessment of risk related to HZO recurrence. See Contraindications and Precautions if considering vaccinating a person with previous HZO.
Vaccine providers are asked to report the following AEFI in particular, through local public health officials:
Refer to Table 1 Vaccine Safety in Part 2 and the User Guide to the Completion and Submission of the AEFI Reports for additional information about AEFI reporting.
HZ vaccine is contraindicated in persons with a history of anaphylaxis after previous administration of the vaccine and in persons with proven immediate or anaphylactic hypersensitivity to any component of the vaccine or its container. Refer to Contents of Immunizing Agents available for use in Canada in Part 1 for lists of vaccines and passive immunizing agents available for use in Canada and their contents. For ZOSTAVAX®, known allergens include neomycin and porcine gelatin.
In situations of suspected hypersensitivity ornon-anaphylactic allergy to vaccine components, investigation is indicated which may involve immunization in a controlled setting. Consultation with an allergist is advised.
With some exceptions (refer to Immunocompromised persons), HZ vaccine should not be given to individuals with primary or acquired immune deficiency due to conditions such as: acute and chronic leukemias; lymphoma; other conditions affecting the bone marrow or lymphatic system; immunosuppression due to HIV/AIDS; or cellular immune deficiencies. Furthermore, the safety and efficacy of HZ vaccine has not been established in adults who are known to be infected with HIV without evidence of immunosuppression.
HZ vaccine should not be administered to individuals who have recently used or are currently using immune suppressive medications outlined in Table 1. The vaccine is not contraindicated for use in individuals who are receiving topical/inhaled corticosteroids or low-dose systemic corticosteroids in people who are receiving corticosteroids as replacement therapy (e.g. for adrenal insufficiency) or low dose immunosuppressives as defined above. Individuals on anti-TNF biologics for inflammatory conditions should be considered on a case by case basis.
|Immunosuppressive medication||Example brand name (company)|
|6-mercaptopurineTable 1 - Footnote *||PURINETHOL®(Novopharm Ltd.)|
|Alemtuzumab||MabCampath®(Genzyme Canada, Div. Of Sanofi-Aventis Canada Inc.)|
|Anti-thymocyte globulin||Thymoglobulin®(Genzyme Canada, Div. Of Sanofi-Aventis Canada Inc.)|
|AzathioprineTable 1 - Footnote *||IMURAN (Triton Pharma Inc.)|
|Basiliximab||SIMULECT™ (Novartis Pharmaceuticals Canada Inc.)|
|Cyclophosphamide||PROCYTOX (Baxter Corp.)
|Cyclosporine||NEORAL™ (Novartis Pharmaceuticals Canada Inc.)|
|High-dose systemic corticosteroids (20 mg/day or more of prednisone or its equivalent for an adult) for 14 days or moreTable 1 - Footnote *|
|Leflunomide||ARAVA®(Sanofi-Aventis Canada Inc.)|
|MethotrexateTable 1 - Footnote *|
|Most cancer chemotherapies (except tamoxifen,hydroxyurea, and gonadotropin release inhibitors which are not considered immunocompromising) - If 3 months post-chemotherapy and the cancer is in remission, the person is not considered immunocompromised|
|Mycophenolate mofetil||CellCept® (Hoffman-LaRoche Ltd.)|
|Sirolimus||Rapamune® (Pfizer Canada Inc.)|
|Tacrolimus||Prograf® (Astellas Pharma Canada Inc.)|
|Non-TNF biologic immunosuppressives used in inflammatory disease||Orencia™ (Bristol-Myers Squibb Canada)
RITUXAN® (Hoffman-LaRoche Ltd.)
Vaccination should be deferred in individuals with active untreated tuberculosis.
HZ vaccine is contraindicated during pregnancy and it is recommended that women avoid pregnancy for at least 4 weeks after the receipt of the vaccine.
As with all live vaccines, there is a theoretical risk of transmission of HZ vaccine virus from vaccinated to susceptible individuals. While post-marketing experience with varicella vaccines has documented transmission of vaccine virus between vaccinees who develop a varicella-like rash and susceptible contacts, no case of transmission of HZ vaccine virus from a vaccinated individual who develops a rash to another person has been documented to date.
If considering immunization of individuals with a history of HZO, it is important to discuss these cases with an ophthalmologist and ensure that patients with a history of HZO no longer have active disease. Patients with a history of HZO should be informed by their healthcare provider that cases of recurrent HZO following vaccine have occurred, although causality has not been established, and the risk of recurrent HZO relative to the potential benefit of preventing future recurrences is unknown.
Administration of HZ vaccine should be postponed in persons suffering from severe acute illness. Immunization should not be delayed because of minor acute illness, with or without fever.
Refer to Contraindications, Precautions and Concerns in Part 2 for additional general information.
Systemic antiviral therapy (such as acyclovir, valacyclovir, famciclovir) should be avoided in the peri-immunization period, as it may reduce the efficacy of VZV-containing vaccine such as HZ vaccine. On the basis of expert opinion, it is recommended that people taking long-term antiviral therapy should discontinue these drugs, if possible, from at least 24 hours before administration of VZV vaccine and should not restart antiviral therapy until 14 days after.
Although no safety or efficacy data are available for the administration of HZ vaccine to individuals who have recently received immune globulins or other blood products, the vaccine is known to be immunogenic in adults with pre-existing antibody to VZV. In theory, administration of Ig should not interfere with the vaccine response; therefore, some experts do not consider recent administration of Ig or blood products as a reason to delay the administration of herpes zoster vaccine. Refer to Blood products, human immune globulin and timing of immunization in Part 1 for additional information concerning the administration of live vaccines and blood products of human origin.