Background The thirteen-valent pneumococcal conjugate vaccine(PCV13)is not included in the national immu-nization program and is administered voluntarily with informed consent in China.In preparation for assessing the...Background The thirteen-valent pneumococcal conjugate vaccine(PCV13)is not included in the national immu-nization program and is 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 of age from four locations in Hainan Province,China.Methods From March to June 2022,nasopharyngeal(NP)swabs,collected from healthy children aged younger than 59 months who lived in the 4 different locations(Haikou,Wanning,Baisha and Qiongzhong)in Hainan Province,were tested for pneumococcus using conventional culture.Pneumococcal isolates were serotyped using the Quel-lung reaction.Risk factors associated with pneumococcal colonization were assessed using univariate analysis and multivariable logistic regression adjusting for age,daycare attendance and other factors.Results Pneumococcus was isolated in 710(30.4%)of the 2333 children enrolled.Of 737 pneumococci,29 serotypes were identifed;60.9%were PCV13 serotypes;the most common vaccine serotypes were 6B(20.4%),19F(13.0%),6A(11.9%)and 23F(6.1%);and the most common nonvaccine serotypes were 23A(12.9%),34(6.1%)and nontypeable(NT)pneumococci(5.6%).Children vaccinated with PCV13 had lower carriage(17.7%vs 32.5%;P=0.0001)and fewer PCV13 serotypes(41.9%vs 62.7%;P=0.0017)compared to unimmunized children.After adjustment,NP carriage Was higher among children attending daycare(aOR=2.3,95%CI:1.7-3.2),living in rural areas(aOR=1.4,95%CI:1.1-1.8),living with siblings(aOR=1.3,95%CI:1.0-1.6)and whose mothers had completed senior high/technical sec-ondary school(aOR=1.5,95%CI:1.1-2.0).In contrast,completion of 3-4 doses of PCV13 were associated with a lower carriage rate(aOR=0.6,95%CI:0.4-0.9).Conclusions We established the baseline of pneumococcal carriage,serotype distribution and PCV13 immuni-zation rates among healthy children under 5 years of age in Hainan Province,prior to the introduction of PCV13 into the national immunization program.The high proportion of PCV13 serotypes suggests that PCV13 introduction will likely have a substantial impact on pneumococcal carriage in Hainan Province.展开更多
基金This research was funded by Bill&Melinda Gates Foundation(No.INV-034554)Beijing Municipal Natural Science Foundation(No.L202007)Special funds for the construction of high-level public health technical personnel from Beijing Municipal Health Commission(No.2022-3-01-021).
文摘Background The thirteen-valent pneumococcal conjugate vaccine(PCV13)is not included in the national immu-nization program and is 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 of age from four locations in Hainan Province,China.Methods From March to June 2022,nasopharyngeal(NP)swabs,collected from healthy children aged younger than 59 months who lived in the 4 different locations(Haikou,Wanning,Baisha and Qiongzhong)in Hainan Province,were tested for pneumococcus using conventional culture.Pneumococcal isolates were serotyped using the Quel-lung reaction.Risk factors associated with pneumococcal colonization were assessed using univariate analysis and multivariable logistic regression adjusting for age,daycare attendance and other factors.Results Pneumococcus was isolated in 710(30.4%)of the 2333 children enrolled.Of 737 pneumococci,29 serotypes were identifed;60.9%were PCV13 serotypes;the most common vaccine serotypes were 6B(20.4%),19F(13.0%),6A(11.9%)and 23F(6.1%);and the most common nonvaccine serotypes were 23A(12.9%),34(6.1%)and nontypeable(NT)pneumococci(5.6%).Children vaccinated with PCV13 had lower carriage(17.7%vs 32.5%;P=0.0001)and fewer PCV13 serotypes(41.9%vs 62.7%;P=0.0017)compared to unimmunized children.After adjustment,NP carriage Was higher among children attending daycare(aOR=2.3,95%CI:1.7-3.2),living in rural areas(aOR=1.4,95%CI:1.1-1.8),living with siblings(aOR=1.3,95%CI:1.0-1.6)and whose mothers had completed senior high/technical sec-ondary school(aOR=1.5,95%CI:1.1-2.0).In contrast,completion of 3-4 doses of PCV13 were associated with a lower carriage rate(aOR=0.6,95%CI:0.4-0.9).Conclusions We established the baseline of pneumococcal carriage,serotype distribution and PCV13 immuni-zation rates among healthy children under 5 years of age in Hainan Province,prior to the introduction of PCV13 into the national immunization program.The high proportion of PCV13 serotypes suggests that PCV13 introduction will likely have a substantial impact on pneumococcal carriage in Hainan Province.
