Phase ? Clinical Trial of 24-valent Pneumococcal Polysaccharide Conjugate Vaccine

In the treatment of pneumococcal diseases, the common use of penicillin-based antimicrobial agents has led to drug resistance, which has become a global challenge. Therefore, disease prevention through vaccination is essential. The 23-valent pneumococcal polysaccharide vaccine, the first widely used vaccine, has limitations. Subsequent pneumococcal polysaccharide conjugate vaccines have improved protection rates but increased cases of infections caused by non-vaccine serotype strains. Currently, vaccines available in China for pneumococcal disease prevention include the 23-valent polysaccharide vaccine (approved only for adults) and the 13-valent conjugate vaccine. PCV24 expands serotype coverage and converts capsular polysaccharides into T-cell-dependent antigens by binding them to proteins, stimulating humoral immunity and the complement system to generate specific antibodies and immunological memory for disease prevention. This study aims to preliminarily investigate the safety and immunogenicity of PCV24 vaccination in Chinese adults.