660. Streptococcus pneumoniae (Pnc) nasopharyngeal carriage (PncNP-CAR)  among school children 6-10 years old from 2 ethnic populations, 12-18 months after introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) into the national immunization program (NIP)
Session: Poster Abstract Session: Pneumococcal Vaccines
Friday, October 21, 2011
Room: Poster Hall B1

 

 

Background:  PncNP-CAR rates among school children are largely unknown but may play an important role in PCV7 serotypes (7VT) transmission after PCV7 implementation. 2 populations reside in Southern Israel: Jewish children (JC) (comparable to a Western population), and Bedouin children (BC) (largely resembling a developing population with very high birth rates and crowding). PCV7 was introduced to the private market (almost exclusively in JC) in 2007-8 (~25% children <2 yrs with ≥2 doses in 2008) and to the NIP in July 2009 (>80% with ≥2 doses in 2010).

Methods: A prospective surveillance of PncNP-CAR among elementary school children 6-10 yrs was initiated 1 year after PCV7 was introduced to the NIP.  Nasopharyngeal swabs were obtained in 2 BC and 2 JC schools in the summer of 2010 (~ 12 m post NIP) and winter of 2011 (~18 m post NIP). Data included family size and antibiotic use.  

Results: Pnc was isolated in 26% (45/173) Jewish children vs. 59% (291/493) Bedouin children (OR: 3.12 [95% CI: 1.96-4.99]). PncNP-CAR was significantly lower in Jewish children aged 9-10 yrs vs. 6-8 yrs: 14.3% (8/56) vs. 31.6% (37/117) (p=0.015). In contrast, no decrease with increasing age was seen among BC. 7VT serotypes were significantly higher in BC vs. JC (OR 2.74 [1.03-9.19]) (Figure). In winter 2011, no 7VT were found among JC, but no significant reduction was found in BC.  Serotype 6A was not reduced during the surveillance in both populations.

 

Conclusion: 12-18 m after PCV7 introduction, 7VT PncNP-CAR among BC age 6-10 yrs was significantly high compared to JC. In contrast no 7VT was found in JC in 2011.  Herd immunity is expected therefore to be of a lesser extent in the early post PCV7 period among the Bedouin population, suggesting that in developing populations, indirect immunity may appear later than in developed populations.  



Subject Category: I. Adult and Pediatric Vaccines

David Greenberg, MD, Noga Givon-Lavi, PhD, Nurith Porat, PhD and Ron Dagan, MD, Ben-Gurion Univ. and Soroka Univ. Med. Ctr., Beer-Sheva, Israel

Disclosures:

D. Greenberg, Pfizer: Speaker's Bureau, Speaker honorarium

N. Givon-Lavi, None

N. Porat, None

R. Dagan, Berna/Crucell: Grant Investigator, Investigator, Scientific Advisor and Speaker's Bureau, Consulting fee, Research grant and Speaker honorarium
GlaxoSmithKline: Scientific Advisor and Speaker's Bureau, Consulting fee and Speaker honorarium
MSD: Grant Investigator, Investigator and Scientific Advisor, Consulting fee and Research grant
Novartis: Scientific Advisor, Consulting fee
Protea: Grant Investigator, Investigator and Shareholder, Research grant
Pfizer (Wyeth): Grant Investigator, Investigator, Scientific Advisor and Speaker's Bureau, Consulting fee, Research grant and Speaker honorarium

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.