13-Valent Pneumococcal Conjugate Vaccine Given Concomitantly with Trivalent Inactivated Influenza Vaccine in Healthy Adults: A Randomized, Double-Blind, Phase 3 Clinical Trial

Background: Persons aged >50 years are at increased risk for developing pneumococcal infections. It is anticipated that a pneumococcal conjugate vaccine will induce quantitatively and possibly qualitatively different immune responses than the current polysaccharide vaccine, leading to induction of immunological memory and enhanced protection against pneumococcal disease in adults. The time of influenza vaccination is an opportunity for pneumococcal vaccination in adults as these vaccines are frequently given at the same time. Both vaccines can be given concomitantly without compromising the immunogenicity of either.

Objectives: To examine the compatibility of concomitant administration of 13-valent pneumococcal conjugate vaccine (PCV13) and trivalent inactivated influenza vaccine (TIV) in healthy adults aged 50 to 59 years.

Methods: Participants naïve to 23-valent pneumococcal polysaccharide vaccine (N=1116) were randomized (1:1 ratio) to receive either PCV13+TIV followed by placebo 1 month later or TIV+placebo followed by PCV13 1 month later. Immunogenicity and safety were assessed.

Results: PCV13+TIV and TIV+placebo yielded similar proportions of responders with a 4-fold increase in TIV antibody titer: A/H1N1, 84.0% vs 81.2%; A/H3N2, 71.1% vs 69.5%; B, 60.6% vs 60.3%, respectively. Noninferiority of PCV13+TIV to TIV+placebo (lower bound of 2-sided 95% CI >–10%)  was demonstrated for all virus subtypes. PCV13 serotype-specific IgG GMCs 1 month after PCV13+TIV ranged from 1.15 to 16.70 µg/mL; 1 month after PCV13 alone, GMCs ranged from 1.46 to 18.84 µg/mL. Noninferiority criterion was met for all serotypes. Most local and systemic events were mild. Local reactions occurred in 88.6% of PCV13+TIV recipients vs 39.4% in recipients of TIV+placebo and 85.1% of those receiving PCV13 alone. Systemic events occurred in 86.2% of PCV13+TIV recipients vs 75.8% in recipients of TIV+placebo and 76.7% of those receiving PCV13 alone.

Conclusions: Concomitantly administered PCV13+TIV demonstrate an acceptable safety and immunogenicity profile compared with TIV or PCV13 given alone.