Immunogenicity and Safety of 3 Formulations of a Respiratory Syncytial Virus Candidate Vaccine in Nonpregnant Women: A Phase 2, Randomized Trial.

BACKGROUND: Respiratory syncytial virus (RSV) is a common cause of respiratory tract illness and hospitalization in neonates and infants. RSV vaccination during pregnancy may protect offspring in their first months of life. METHODS: This randomized, observer-blind, multicenter, phase 2 study evaluated the immunogenicity and safety of an RSV candidate vaccine in healthy nonpregnant women aged 18-45 years. Four hundred participants were randomized (1:1:1:1) to receive a single intramuscular dose of vaccine containing 30 µg, 60 µg, or 120 µg of RSV fusion protein engineered to preferentially maintain a prefusion conformation (RSV-PreF vaccine) or placebo. RESULTS: Thirty days postvaccination, RSV-A neutralizing antibody geometric mean titers (GMTs) increased 3.75-, 4.42- and 4.36-fold; RSV-B neutralizing antibody GMTs 2.36-, 2.54- and 2.76-fold; and palivizumab competing antibody (PCA) concentrations 11.69-, 14.38- and 14.24-fold compared with baseline levels in the 30 µg, 60 µg, and 120 µg RSV-PreF groups, respectively. Antibody titers and PCA concentrations at day 30 were significantly higher with the 120 µg compared to the 30 µg RSV-PreF vaccine. All RSV-PreF vaccine formulations and the placebo had similar reactogenicity profiles. No serious adverse events were considered to be related to the RSV-PreF vaccine. CONCLUSIONS: The 3 formulations of the investigational RSV-PreF vaccine were well-tolerated and induced RSV-A and RSV-B neutralizing antibodies and PCAs in healthy, nonpregnant women. CLINICAL TRIALS REGISTRATION: NCT02956837.

Immunogenicity and safety of the adjuvanted recombinant zoster vaccine co-administered with the 23-valent pneumococcal polysaccharide vaccine in adults ≥50 years of age: A randomized trial.

BACKGROUND: This study evaluated immunogenicity and safety of the adjuvanted recombinant zoster vaccine (RZV) when the first dose was co-administered with the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in adults aged ≥50 years. METHODS: In this open label, multi-center study (NCT02045836), participants were randomized 1:1 to receive either the first dose of RZV and PPSV23, co-administered at Day 0 and the second dose of RZV at Month 2 (Co-Ad group), or PPSV23 at Day 0, the first dose of RZV at Month 2 and second dose of RZV at Month 4 (Control group). Co-primary objectives were the RZV vaccine response rate (VRR) in the Co-Ad group and the non-inferiority of the antibody responses to RZV and PPSV23 in the Co-Ad group compared to the Control group. Reactogenicity and safety were also assessed. RESULTS: 865 participants were vaccinated (Co-Ad: 432, Control: 433). VRRs to RZV were >98% in both groups. Humoral immune responses to co-administration of RZV and PPSV23 were non-inferior to sequential administration. All three co-primary immunogenicity objectives were met. Solicited local symptoms after the first RZV dose were reported by similar percentages of participants in both groups. Solicited general symptoms were more frequently reported when the first dose of RZV and PPSV23 were co-administered. No differences were apparent between groups after the second RZV dose. CONCLUSIONS: No immunologic interference was observed between RZV and PPSV23 when co-administered in adults ≥50 years. No safety concerns were raised.