New Herpes Zoster Vaccine: What the Hematologist Needs to Know

The lifetime risk of developing herpes zoster (HZ), the clinical manifestation of varicella zoster virus (VZV) reactivation, is estimated to be 20 to 30 percent, with an incidence in the United States of about one million cases each year.¹  The risk typically increases with age (especially older than age 50 years) and when cell-mediated immunity is diminished, as occurs with use of immunosuppressive drugs.^1-3  Zoster vaccine live (Zostavax; Merck & Co., Inc., Whitehouse Station, NJ), a vaccine containing a strain of live attenuated VZV, was approved by the U.S. Food and Drug Administration (FDA) in 2006 after it was shown to reduce the incidence of HZ by 51.3 percent in a study of 38,000 adults aged 60 years and older. The vaccine also reduced the number of cases of postherpetic neuralgia (PHN), and the severity/duration of pain associated with HZ by 66.5 percent and 61.1 percent, respectively.¹  In the United States, recommendations for the use of vaccines are created by the Advisory Committee on Immunization Practices (ACIP), a committee of medical and public health experts reporting to the director of the Centers for Disease Control and Prevention (CDC), that are then accepted and promoted by the CDC. In 2006, CDC/ACIP recommended that zoster vaccine live be given to all adults aged 60 years and older, including those with a previous episode of HZ and those not recalling having had chickenpox. In 2011, the FDA approved the vaccine’s use in individuals 50 to 59 years of age.¹  On October 20, 2017, a recombinant zoster vaccine, zoster vaccine recombinant (Shingrix; GlaxoSmithKline Biologicals, Rixensart, Belgium), was approved by the FDA for the prevention of HZ in adults aged 50 years and older based on a phase III clinical study that showed a sustained efficacy of more than 90 percent against HZ across all age groups during a four-year follow-up period (HZ prevention: efficacy of 96.6% in ages 50-59 years, 97.4% in ages 60-69 years, and 91.3% in ages ≥70 years; PHN: efficacy of 91.2% in ages ≥50 years and 88.8% in ages ≥70 years).⁴ 

• Given how prevalent HZ is and how frequently immunosuppressive therapy is prescribed for the treatment of hematologic disorders, the present CDC/ACIP publication by Dr. Kathleen Dooling and colleagues is highly relevant for the practicing hematologist. CDC/ACIP recommend that for the prevention of HZ and related complications, zoster vaccine recombinant is preferred over zoster vaccine live. As with zoster vaccine live, the CDC/ACIP recommend the use of zoster vaccine recombinant in all persons older than 50 years, in persons taking low-dose immunosuppressive therapy (e.g., <20 mg/day of prednisone or equivalent, or using inhaled or topical steroids), and in those anticipating immunosuppression or who have recovered from an immunocompromising illness (Table). The ACIP has not made recommendations regarding the use of zoster vaccine recombinant in immunocompromised persons and those on moderate to high doses of immunosuppressive therapy as these patients were excluded from the phase III efficacy studies (ZOE-50 and ZOE-70 trials).⁴  This patient population will likely be discussed at upcoming ACIP meetings as additional data become available. However, published data have already shown that patients immunized with zoster vaccine recombinant who were 18 years or older, had hematologic malignancies (excluding non-Hodgkin B cell lymphoma or chronic lymphocytic leukemia), and completed or are undergoing immunosuppressive cancer therapy, showed a robust humoral and cellular immune responses to the vaccine at one month after last dose, with no safety concerns at six months follow-up after last dose.⁵