The FDA has expanded the indication for recombinant zoster vaccine (RZV), adjuvanted (Shingrix; GlaxoSmithKline) to include prevention of shingles in immunocompromised adults 18 years and older.1
RZV was initially approved in 2017 for the prevention of adults 50 years and older. This new indication expands the number of high-risk individuals eligible to receive the vaccine for protection against shingles.
The approval of this expanded indication is based on data from clinical studies evaluating the safety and efficacy of RZV in adults who had undergone autologous hematopoietic stem cell transplant (auHSCT) and those undergoing treatment for hematological malignancies (post-hoc analysis).1,2 Although RZV is intended to be administered in 2 doses, 2 to 6 months apart, the second can be administered 1 to 2 months after the first dose for adults who are or will be immunodeficient or immunosuppressant, according to GSK.1
The efficacy of RZV in immunocompromised adults was evaluated in 2 separate studies. One phase 3 randomized placebo-controlled, observer-blind trial included 1721 participants who received an auHSCT 50 to 70 days before dose 1 of RZV and were expected to receive prophylactic antiviral therapy for 6 months or more post-transplant. In a posthoc analysis of another clinical study, 515 participants with hematological malignancies received the first dose of RZV or placebo during or within 6 months of completing immunosuppressive chemotherapy.2
The study participants were followed for the development of herpes zoster (HZ) and post-herpetic neuralgia (PHN), a complication of HZ, for a median of 21 months. According to the efficacy analysis for the auHSCT study, no confirmed HZ cases were determined by either PCR or by a Clinical Evaluation Committee. Compared with placebo, RZV significantly reduced the risk of developing HZ in adult recipients who received an auHSCT, the results concluded.2
The posthoc analysis of participants with hematological malignancies showed no confirmed HZ cases either, demonstrating that RZV is 87.2% effective against the development of HZ. The incidence rate of HZ per 1000 person-years was 8.5 versus 66.2 in the RZV and placebo groups, respectively.2
Local adverse effects (AEs) reported within 7 days following vaccination in auHSCT recipients were pain, redness, and swelling. General AEs included fatigue, myalgia, headache, gastrointestinal symptoms, shivering, and fever. Additional safety data were evaluated in 6 placebo-controlled clinical studies including 3116 individuals 18 years and older from 5 different immunodeficient or immunosuppressed populations.2
The CDC’s Advisory Committee on Immunization Practices has begun discussions to consider recommendations for the use of RZV in immunocompromised adults.1