A Phase 1/2 Clinical Trial Evaluating Safety and Immunogenicity of a Varicella Zoster Glycoprotein E Subunit Vaccine Candidate in Young and Older Adults

An adjuvanted recombinant varicella zoster virus (VZV) subunit vaccine is being developed for the prevention of herpes zoster and its complications.In a phase I/II, open-label, randomized, parallel-group study, older adults (50-70 years) received 2 doses 2 months apart of an adjuvanted recombinant glycoprotein E vaccine (HZ/su; n = 45), a live attenuated Oka strain VZV vaccine (OKA; n = 45), or HZ/su and OKA administered concomitantly (n = 45). To evaluate safety prior to administration in older adults, young adults (18-30 years) were vaccinated with 2 doses 2 months apart of HZ/su (n = 10) or OKA (n = 10). Safety and immunogenicity were assessed up to 42 months for older adults immunized with HZ/su and up to 12 months for all others.Few grade 3 events and no severe adverse events were reported. Fatigue, myalgia, headache, and injection site pain were the most common solicited reactions for HZ/su and occurred more frequently than with OKA. CD4(+) T-cell and humoral immune responses were much higher with HZ/su than with OKA and remained elevated until 42 months. Addition of OKA to HZ/su did not increase immunogenicity.In this study, HZ/su adjuvanted subunit vaccine was well tolerated and more immunogenic than a live attenuated VZV vaccine. Clinical Trial registration. NCT00492648 and NCT00492648.