Previous studies have demonstrated the immunogenicity and safety of the co-administration of the trivalent inactivated influenza vaccine (IIV3) with the polysaccharide pneumococcal vaccine (PPV) or pneumococcal conjugate vaccine (PCV). However, there is no direct comparison study that evaluates the immunogenicity and safety of IIV3 given concomitantly with PCV13 or PPV23 in the elderly.

During the 2012-2013 influenza vaccination period, 224 healthy elderly volunteers aged 65 years and older randomly received IIV3 given concomitantly with either PCV13 (PCV13+IIV3) or PPV23 (PPV23+IIV3) in a 1:1 ratio. Serum hemagglutination-inhibiting antibodies for IIV3 were measured at the time of vaccination and 1 month after vaccination. Adverse events were recorded prospectively in a clinical diary during a 7-day period.

A total of 220 participants blood samples for analysis of immunogenicity and kept a clinical diary for safety analysis (PCV13+IIV3, n=110; PPV23+IIV3, n=110). One month after vaccination, both groups satisfied the Committee for Medical Products for Human Use criteria for A/H1N1, A/H3N2 and B strains, showing comparable seroprotection rates, seroconversion rates and geometric mean titer fold. The assessments of immunogenicity were similar in both groups. The most common local and systemic reactions were pain at the injection site and generalized myalgia. They were generally mild or moderate in intensity. The adverse events were not statistically different between the two groups.

PCV13+IIV3 and PPV23+IIV3 demonstrated similar immunogenicity and safety in the elderly.