Impact of Pneumococcal Conjugate Vaccine and of Reduction of Antibiotic Use on Nasopharyngeal Carriage of Nonsusceptible Pneumococci in Children With Acute Otitis Media

Abstract

Implementation of PCV7, combined with a reduction in antibiotic use, in a country with a high prevalence of antibiotic-resistant pneumococci appears to have a strong impact on the carriage of penicillin nonsusceptible pneumococci in children with AOM.

Pneumococcal Nasopharyngeal Carriage following Reduced Doses of a 7-Valent Pneumococcal Conjugate Vaccine and a 23-Valent Pneumococcal Polysaccharide Vaccine Booster

“…Our NVT carriage rate (approximately 40%) is higher than those reported by the reduced-dose Netherlands study: 15 to 17% for the vaccinated groups and 8% for the unvaccinated control group (40). The NVT carriage rates reported in observational studies of children from industrialized countries following PCV tend to be lower (18% in the United States [11] and 15.5% in France [4]). However, NVT carriage rates following vaccination of children from nonindustrialized countries (77% in the Gambia [27] and 36% in South Africa [23]) and high-risk disadvantaged communities (39.2% for Navajo and White Mountain Apache children [24]) tend to be higher.…”

“…Since the routine introduction of PCV into national infant immunization schedules, a number of carriage surveys have documented the effect of PCV on NP pneumococcal carriage. Like the clinical trials, all these studies have reported a reduction in VT carriage (4,8,11,15,17,18,26,34), particularly in those children who are up to date with their immunizations (4,17,26), have had a PCV booster in the second year of life (4, 11), or have not had prolonged intervals between PCV doses (17).…”

“…Since the routine introduction of PCV into infant national immunization schedules, a number of carriage surveys have documented the effect of PCV on NP pneumococcal carriage. Like the clinical trials, all these studies have found that there has been a reduction in VT carriage (4,8,11,15,17,18,26,34). NVT colonization has increased following vaccination, with serogroups 11 and 15 being commonly reported (4,8,11,15,18,34), and more recently, the newly identified serotype 6C has been reported (31).…”

Impact of a Pneumococcal Conjugate Vaccination Program on Carriage among Children in Norway

“…The prevalence of nasopharyngeal pneumococcal colonization among children in Norway is very high compared to prevalences reported from other European and North American settings (2,4,13,15,19,28). Furthermore, the prevalence remained unchanged following the introduction of PCV7 (77.7% before and 80.2% after widespread vaccination).…”

“…S. pneumoniae colonizes the nasopharynx and is considered a part of the normal flora in early childhood (1). Following the implementation of childhood vaccination with the seven-valent conjugated pneumococcal vaccine (PCV7), reports from several locations have described declines in carriage of the seven serotypes included in the vaccine, i.e., serotypes 4, 6B, 9V, 14, 18C, 19F and 23F (4,6,13,19,24). Due to reduced transmission of PCV7 serotypes, the incidence of invasive pneumococcal disease (IPD) declines also among the unvaccinated, which is an indirect effect of conjugate pneumococcal vaccination.…”