NEW ORLEANS, LA—An investigational herpes zoster subunit vaccine significantly reduces disease risk as well as severity in those who develop breakthrough disease in adults 50 years and older, a study presented at IDWeek has concluded.

This results in improved quality of life, noted Desmond Curran, PhD, Health Economics, GSK Vaccines, Wavre, Belgium, on behalf of the study investigators.

The 2 placebo-controlled Phase 3 studies, ZOE 50 (NCT01165177) and ZOE 70 (NCT01165229), examined efficacy of a herpes zoster subunit vaccine in adults aged ≥50 and ≥70 years, respectively. The vaccine contains recombinant varicella-zoster virus glycoprotein E and the AS01B Adjuvant System.

Patients received 2 doses of the vaccine or placebo intramuscularly 2 months apart. Quality of life was assessed using the Short-Form Health Survey (SF-36) and the Euro-Quality of Life – 5 Dimension (EQ-5D) at baseline, months 14, 26, and 38, as well as in conjunction with the Zoster Brief Pain Inventory (ZBPI) during suspected herpes zoster episodes.

Quality of life scores were compared between the 2 groups in confirmed cases of herpes zoster. Vaccine efficacy in reducing the ZBPI Burden of Illness and Burden of Interference scores were estimated in the modified total vaccinated cohort (mTVC).

“The latter 2 scores are calculated from the area under the curve (Days 0 to 182) of the ZBPI Worst pain and ZBPI Activities of Daily Living scores, respectively, assuming a score of 0 for subjects who do not have a confirmed herpes zoster episode,” Dr. Curran reported.

The ZOE 50 group included 7,304 mTVC subjects in the herpes zoster subunit vaccine arm and 7,413 in the placebo arm, with 9 and 254 confirmed cases of herpes zoster, respectively.

In the ZOE 70 prespecified combined study population, which included those age ≥70 years (ZOE 70+), there were 8,250 mTVC subjects in the herpes zoster subunit vaccine arm and 8,343 in the placebo arm, with 25 and 284 confirmed cases of herpes zoster.

When results of the ZBPI questionnaire were analyzed, the mean maximum worst pain in the ZOE 50 group was 5.5 vs. 6.7 in the placebo arm (P=0.1133) and mean maximum average pain was 3.9 vs. 5.5, respectively (P=0.0486).

In the 70+ group, mean maximum worst pain was 5.7 vs. 7.0 in the placebo arm (P=0.0316) and mean maximum average pain was 4.5 vs. 5.6, respectively (P=0.0431).

The Burden of Illness Efficacy was 98.4% in the ZOE 50 and 92.1% in the ZOE 70+ groups, and the Burden of Interference Efficacy was 99.1% and 90.3%, respectively.