Safety and Immunogenicity of a Newly 23-valent Pneumococcal Polysaccharide Vaccine in Chinese Adults and Children

A newly 23-valent pneumococcal polysaccharide vaccine was developed with promising safety and immunogenicity demonstrated in the phase III trial in China. A large scale, double blind, randomized, PNEUMOVAX 23 (Merck \& Co., Inc.) controlled phase 3 clinical trial was conducted.

The World Health Organization (WHO) estimated that more than 800 000 children younger than 5 years died from pneumococcal disease in 2000, making it the leading vaccine-preventable cause of death. Pneumococcal polysaccharide vaccines have progressed from 2-valent vaccines to the current 23-valent vaccine, which has been available since the early 1980s. The 23-valent vaccine includes serotypes accounting for 72% to 95% of invasive pneumococcal disease, depending on the geographic area. Many countries have added pneumococcal polysaccharide vaccine to their existing national immunization programs or recommended it for people aged 65 years and older and for individuals aged 2-64 who are at increased risk of pneumococcal disease. A newly 23-valent pneumococcal polysaccharide vaccine was developed with promising safety and immunogenicity demonstrated in the phase III trial in China. A large scale, double blind, randomized, PNEUMOVAX 23 (Merck \& Co., Inc.) controlled phase 3 clinical trial was conducted.