TITLE:
Impact of the Pneumococcal Heptavalent Conjugated Vaccine on Streptococcus pneumoniae Nasopharyngeal Carriage and Antimicrobial Susceptibility in Children 2-5-Year-Old in Beijing, China
AUTHORS:
Min Lv, Shuang Bai, Yanni Sun, Tiegang Zhang, Aihua Li, Jiang Wu
KEYWORDS:
Heptavalent Pneumococcal Vaccine, Streptococcus Pneumoniae, Serotypes, Nasopharyngeal Carriage, Antimicrobial Non-Susceptibility
JOURNAL NAME:
World Journal of Vaccines,
Vol.7 No.3,
August
30,
2017
ABSTRACT:
Streptococcus pneumoniae is a primary cause of illness and death among
children younger than 5 years in China. The heptavalent pneumococcal conjugate
vaccine (PCV7) was the only conjugated vaccine (PCV) available in
China from 2008 to 2013. This randomized, controlled, open-label study
conducted at 46 Beijing clinics involved 3281 healthy 2-5-year-old Chinese
children, randomized 1:1 to receive one dose of the S. pneumoniae heptavalent conjugated vaccine (PCV7) (n = 1643) or Haemophilus influenzae type b
conjugate vaccine (Hib) (n = 1638). The main objective of this study was to
investigate the impact of PCV7 against that of Hib vaccination in the nasopharyngeal S. pneumoniae colonization in healthy Chinese children. Nasopharyngeal
(NP) samples for culture, serotyping and antimicrobial susceptibility
testing were collected before vaccination and at Day 60 and 180 post-vaccination.
A total 3281 children were enrolled in the study. Demographic characteristics
were similar among both study groups: 1641 children received PCV7. Before
immunization, S. pneumoniae was isolated in 338 and 360 children in the
PCV7 (144 PCV7 isolates) and Hib groups (145 PCV7 isolates), respectively.
At Day 180, PCV7 vaccination was more effective than Hib vaccination in reduction
NP carriage (20.2% [P = 0.052]) and new acquisition (19.0% [P =
0.066]). When reductions in NP carriage and new acquisition of PCV7 VT
plus 6A was analyzed, reduction in the PCV7 vaccinated group achieved statistical
significance (P = 0.034 and P = 0.042 versus Hib, respectively). NP carriage
of NVT increased in both groups (P = 0.305 between study groups at Day 180).
PCV7 decreased NP carriage of non-susceptible VT to amoxicillin (P = 0.000), ceftriaxone (P = 0.047) and MDR (P = 0.024) versus Hib. PCV7 vaccination in
Chinese children 2 to 5 years of age was more effective than vaccination with
Hib in the reduction of S. pneumoniae nasopharyngeal carriage, new acquisition
and non-susceptible isolates.