A phase III clinical study was done in a population greater than or equal to 2 years to assess the safety and immunogenicity of a novel 23-valent pneumococcal polysaccharide vaccine (PPV23). Researchers carried out a randomized, double-blind, active-controlled experiment in which 1760 individuals were randomly allocated to receive one dose of either the test vaccination or the control commercial vaccine in a 1:1 ratio. The observation period lasted 28 days. The anti-pneumococcal 2-fold rise rate for 23 serotypes ranged from 49.71% to 90.96% in the treatment group and from 44.52% to 88.24% in the control group. All 23 serotypes of the treatment group were non-inferior to the control group based on a negative 10% non-inferiority margin and 95% confidence intervals of rate difference. Serious adverse events occurred in 2 out of 879 treatment group participants and 2 out of 880 control group participants, and all of the adverse events were unrelated to the immunization. The 23 serotypes of the treatment group were non-inferiority to the control group. The 2-fold increase rate of anti-pneumococcal antibodies was significantly higher in the treatment group for 11 serotypes including 1, 2, 3, 4, 10A, 11A, 14, 18C, 20, 22F, and 23F.
The overall incidence of adverse responses did not differ between the treatment and control groups, and the majority of adverse reactions were mild to moderate in severity.