Recombinant Zoster Vaccine May Attenuate Pain Symptoms in Breakthrough Cases

The recombinant zoster vaccine (RZV) was found to reduce herpes zoster-associated pain and analgesic use among some patients with breakthrough infection, according to results of a study published in Pain.

Investigators pooled data for this analysis from 3 randomized, placebo-controlled, phase III trials: ZOE-50 (ClinicalTrials.gov Identifier: NCT01165177), ZOE-70 (ClinicalTrials.gov Identifier: NCT01165229, and ZOE-HSCT (ClinicalTrials.gov Identifier: NCT01610414). In this analysis, the efficacy of RZV for reducing the duration of pain and pain medication use for breakthrough infection were evaluated. Clinically significant pain was defined as a Zoster Brief Pain Inventory pain score of 3 or more.

Herpes zoster infection was confirmed in 9 RZV recipients and 254 placebo recipients in ZOE-50 (n=15,411), in 23 RZV recipients and 223 placebo recipients in ZOE-70 (n=13,900), and in 49 RZV recipients and 135 placebo recipients ZOE-HSCT (n=1846).

Use of herpes zoster-associated pain medication among confirmed cases ranged from 43.5% to 66.7% among patients receiving the RZV vaccine and from 69.6% to 74.8% among patients in the control groups. The efficacy for reducing pain medication use was significant for the ZOE-70 trial data (vaccine efficacy [VE], 39.6%; 95% CI, 10.8-64.8; P =.008) but not for the ZOE-50 (VE, 11.7%; 95% CI, -19.4 to 53.6; P =.697) or the ZOE-HSCT (VE, 6.2%; 95% CI, -15.8 to 27.8; P =.594) trials.

The average duration of pain medication use ranged from 26.0 to 109.5 days for the vaccine recipients and from 76.1 to 199.3 days for the placebo recipients. Similarly, vaccine efficacy for reducing pain medication use duration was significant for the ZOE-70 trial data (VE, 49.3%; 95% CI, 2.9-73.5; P =.040) but not for the ZOE-50 (VE, 24.7%; 95% CI, -73.7 to 67.4; P =.506) or the ZOE-HSCT (VE, 22.5%; 95% CI, -15.9 to 48.1; P =.214) trials.

The RZV demonstrated significant efficacy for reducing clinically significant herpes zoster-associated pain in the ZOE-HSCT trial (VE, 38.5%; 95% CI, 11.1-57.5; P =.010) but not in the ZOE-50 (VE, 26.9%; 95% CI, -59.6 to 66.5; P =.432) or the ZOE-70 (VE, 28.4%; 95% CI, -17.7 to 56.4; P =.188).

A major limitation of this analysis was that all of the trials lacked sufficient power to detect significant differences in these pain outcomes.

These data indicated that the RZV may attenuate some symptoms of pain in herpes zoster breakthrough cases and that overall, there were few breakthrough cases. The investigators concluded, “[F]or patients experiencing such episodes, particularly those at risk for [herpes zoster], RZV has the potential to attenuate severity and duration of the disease, thereby maintaining QoL.”

Disclosure: This research was supported by GlaxoSmithKline Biologicals SA. Some study authors were employed by GlaxoSmithKline Biologicals SA and also declared affiliations with biotech, other pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.