08. Concomitant Administration of the Adjuvanted Recombinant Zoster Vaccine (RZV) with 13-Valent Pneumococcal Conjugate Vaccine (PCV13) Is Safe and Does Not Interfere with Immunogenicity of Either Vaccine in Adults Aged ≥ 50 Years

Background This study assessed non-inferiority of humoral immunogenicity, reactogenicity, and safety of RZV when the 1st dose was co-administered with PCV13 in adults ≥ 50 years of age (YOA) compared to sequential administration. Methods In this phase 3b, open-label, multi-center study (NCT03439657), adults were randomized 1:1 to receive either the 1st RZV dose co-administered with PCV13 at day (D)1 and the 2nd RZV dose at month (M)2 (Co-Ad group), or PCV13 at D1, the 1st RZV dose at M2 and the 2nd RZV dose at M4 (Control group). Co-primary confirmatory objectives were: (i) vaccine response rate (VRR) to RZV at 1 month post-dose 2 in Co-Ad group; (ii) non-inferiority of humoral responses to RZV (1 month post-RZV dose 2) and PCV13 (1 month post-PCV13) in Co-Ad group compared to Control group. Solicited adverse events (AEs) until D7 post-vaccination and unsolicited AEs until D30 post-vaccination were recorded. Serious AEs (SAEs) and potential immune-mediated diseases (pIMDs) were collected through 12 months post-RZV dose 2. Immunogenicity was performed in the per-protocol set (PPS) and safety analyses in the exposed set. Results Of 912 vaccinated adults, 863 were included in PPS (Co-Ad: 427; Control: 436). VRR for anti-glycoprotein E antibody concentrations was 99.1% in Co-Ad group. The predefined non-inferiority criteria for the humoral immune responses to RZV and PCV13 were met (Table 1). The overall frequency of solicited local AEs after RZV and PCV13 was comparable between Co-Ad and Control groups. Pain was the most common solicited local AE (Figure 1). The frequency of solicited general AEs was similar for the 1st RZV dose when co-administered with PCV13 or alone (57.4% vs 54.6%). Myalgia and fatigue were the most common solicited general AEs (Figure 2). The frequency (Co-Ad: 21.2%; Control: 23.1%) and nature of unsolicited AEs were balanced between groups. None of the reported SAEs, fatal SAEs, or pIMDs were vaccine-related. Table 1. Co-primary confirmatory objectives: vaccine response rate (VRR), and non-inferiority of the immune responses to RZV (1 month post-dose 2) and to PCV13 (1 month post-vaccination) in the Co-Ad group vs the Control group (per-protocol set) Figure 1. The incidence of solicited local adverse events (AEs) occurring within 7 days post-vaccination (overall/adult, exposed set) Figure 2. The incidence of solicited general adverse events (AEs) post-dose 1 occurring within 7 days post-vaccination (exposed set) Conclusion Co-administration of the 1st RZV dose with PCV13 showed non-inferior immune responses to sequential administration. The reactogenicity and safety of RZV in the Co-Ad group were within the range of the established safety profile of RZV. Co-administration of RZV with PCV13 may improve vaccination rates in ≥ 50 YOA population. Funding GlaxoSmithKline Biologicals SA Disclosures Ji-Young Min, PhD, GSK group of companies (Employee) Agnes Mwakingwe-Omar, MD, PhD, GSK group of companies (Employee) Megan Riley, PhD, GSK group of companies (Employee, Shareholder) Lifeter Yenwo Molo, BsC(hons) MSc(hons), GSK group of companies (Employee) Jyoti Soni, MA, GSK group of companies (Employee) Ginette Girard, MD, Diex Recherche Inc. Sherbrooke (Scientific Research Study Investigator) Jasur Danier, MD, GSK group of companies (Employee, Shareholder)