Affiliation:
1. Beijing Center for Disease Prevention and Control
2. Hainan Provincial Center for Disease Control and Prevention
3. Haikou Center for Disease Control and Prevention
4. Wanning Center for Disease Control and Prevention
5. Baisha Country Center for Disease Control and Prevention
6. Qiongzhong Country Center for Disease Control and Prevention
Abstract
Abstract
Background The thirteen-valent pneumococcal conjugate vaccine (PCV13) is not included in the national immunization program and administered voluntarily with informed consent in China. In preparation for assessing the impact of pilot introduction in Hainan Province, we conducted a carriage study among children under 5 years old from four regions in Hainan Province.
Methods In 2022, nasopharyngeal (NP) swabs collected from healthy children were tested for pneumococcus using conventional culture. Pneumococcal isolates were serotyped using the Quellung reaction. Risk factors associated with pneumococcal colonization were assessed using univariate analysis and multivariable logistic regression adjusting for age, daycae attendance and other factors.
Result Pneumococcus was isolated in 710 (30.4%) of the 2333 children enrolled. Of 737 pneumococci, 29 serotypes were identified; 60.9% were PCV13 serotypes; the most common were 6B (20.4%), 19F (13.04%), 6A (11.9%) and 23F (6.1%); and the most common non-vaccine serotypes were 23A (12.9%), 34 (6.08%) and nontypeable (NT) pneumococci (5.6%). Children vaccinated with PCV13 had lower carriage (17.7% vs 32.5%; P=0.0001) and fewer were PCV13-type (41.9% vs 62.7%; P=0.0017) compared to unimmunized children. After adjustment, NP carriage was higher among children attending daycae and those with siblings; living in urban areas, mothers who had completed senior high/technical secondary school and completion of 3-4 doses of PCV13 were associated with a lower carriage rate.
Conclusions We established the baseline of pneumococcal carriage, serotype distribution and PCV13 immunization rates among healthy children under 5 years old in Hainan Province, prior to the introduction of PCV13 into national immunization. The high proportion of PCV13 serotype suggests that PCV13 introduction will likely have substantial impact on pneumococcal carriage in Hainan Province.
Publisher
Research Square Platform LLC
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