Vaccination pattern of the 23-valent pneumococcal polysaccharide vaccine (PPV23) in Hangzhou, China: a coverage and adverse events following immunization of different age groups

Background 23-valent pneumococcal polysaccharide vaccine (PPSV23) has been used to prevent pneumococcal disease, and PPSV23 became available in 2003 in Hangzhou, China as a private-sector, vaccinee-chosen vaccine. No national guidelines for PPSV23 have been developed. We analyzed PPSV23 coverage and utilization in Hangzhou to determine patterns of PPSV23 use and the occurrence of adverse events following immunization (AEFI) in Hangzhou. Materials and Methods Individuals over 2 years of age in Hangzhou were included. Vaccination data during 2006-2017 was retrieved from Hangzhou's Immunization Information System (HZIIS). We used descriptive epidemiological methods to determine PPSV23 usage patterns and AEFI occurrence. Results In 2017, there were 9,027,973 persons above 2 years of age with the coverage of PPSV23 of 2.98%. The coverage of PPSV23 among elders ranged from 0.17% to 0.69%, and the overall coverage was higher in urban areas (3.70%) than in rural (3.34%) and suburban areas (2.16%). 93.45% of 268957 recipients were vaccinated with PPSV23 at 2-4 years of age. 394 AEFI of PPSV23 cases were reported to the Chinese national adverse event following immunization information system (CNAEFIS) during 2008-2017, with the reporting rate of 140.39 per 100,000 doses. Conclusion Persons in Hangzhou had overall low PPSV23 vaccination coverage especially for adults. Most of PPSV23 were used in children, while the proportion of the old population over 60 years slightly increased over year. PPSV23 was safe with a low reported AEFI rate, which was a little higher for children than for the elderly (over 60 years).