Two doses of recombinant zoster vaccine significantly reduced incidence of herpes zoster in adults who had undergone autologous hematopoietic stem cell transplantation (HSCT), results of a randomized, placebo-controlled trial indicate.
The incidence of herpes zoster was 30 per 1,000 person-years for patients who received the adjuvanted recombinant zoster vaccine (Shingrix) versus 94 per 1,000 person-years for those who received placebo, according to study results.
Recombinant zoster vaccine induced humoral and cellular responses that were strong and occurring at a rate higher than what was seen in the placebo group, said senior author Keith M. Sullivan, MD, of Duke University Medical Center, Durham, N.C., and coauthors, who reported findings on behalf of the Zoster Efficacy Study in Patients Undergoing HSCT (ZOE-HSCT) Study Group.
“The vaccinations were generally well tolerated, and most symptoms were mild and transient and did not substantially deter participants from receiving their second dose,” Dr. Sullivan and colleagues wrote in JAMA.
The risk of herpes zoster is increased for 2-3 years after autologous HSCT because of diminished T-cell immunity, according to the authors.
“Antiviral prophylaxis is commonly administered to patients after HSCT to prevent such complications, but the efficacy depends on adherence to treatment,” they said.
While vaccines could provide long-term protection, immunocompromised individuals receiving live attenuated vaccine would be at increased risk of varicella caused by spread of the vaccine strain, they added.
There have been a few encouraging recent studies of non-live vaccines in this setting, including one large phase 3 trial of a heat-inactivated varicella-zoster virus vaccine that showed patients undergoing autologous HSCT had a 63.8% estimated efficacy in preventing herpes zoster, investigators from that study said in The Lancet (2018 May 26;391[10135]:2116-27).
A phase 1/2a study of the adjuvanted recombinant zoster vaccine in patients undergoing HSCT demonstrated strong humoral and cell-mediated immunity responses, which provided the rationale for studying the vaccine further in the randomized ZOE-HSCT study, according to Dr. Sullivan and coauthors.
Their study included a total of 1,846 adults who had undergone autologous HSCT. They were randomized to receive two doses of the recombinant zoster vaccine, the first at 50-70 days after the procedure and the second 1-2 months later.
Herpes zoster cases were seen in 49 and 136 individuals in the vaccine and placebo groups, respectively, which resulted in overall incidences of 30 and 94 per 1,000 person-years.
The incidence rate ratio of a first episode of herpes zoster was 0.36 for individuals receiving at least one dose, which authors said was equivalent to a vaccine efficacy of 63.7%.
That efficacy rate is “very similar” to the estimated efficacy reported for the heat-inactivated varicella-zoster virus vaccine reported in The Lancet, said Dr. Sullivan and coauthors.
However, the heat-inactivated vaccine achieved that level of protection with a four-dose schedule, including one dose given prior to autologous HSCT.
“An advantage of the short 2-dose posttransplantation schedule is that more patients might complete the vaccination program,” they said in a discussion of the results, noting that 94.7% of the recombinant zoster vaccine recipients completed two doses, compared with 81.9% of recipients who received the heat-inactivated herpes zoster vaccine in the previous report.
The study was funded and sponsored by GlaxoSmithKline Biologicals SA. Dr. Sullivan reported disclosures related to GlaxoSmithKline (GSK), Kiadis Pharmaceutical, Roche Genentech, and the National Institute of Allergy and Infectious Diseases. Coauthors provided disclosures related to GSK, AbbVie, Roche, Gilead, Janssen, Pharmacyclics, Morphosys, Helsinn, Celgene, and others.
SOURCE: Bastidas A et al. JAMA. 2019 July 9. doi: 10.1001/jama.2019.9053.