Pneumococcal conjugate vaccination and nasopharyngeal acquisition of pneumococcal serotype 19A strains.
JAMA
; 304(10): 1099-106, 2010 Sep 08.
Article
em En
| MEDLINE
| ID: mdl-20823436
ABSTRACT
CONTEXT The rapid increase in multiresistant serotype 19A as a cause of invasive and respiratory pneumococcal disease has been associated in time with the widespread implementation of 7-valent pneumococcal conjugate vaccination (PCV-7) in several countries. Because spontaneous fluctuations in time and antibiotic selective pressure may have induced this serotype 19A increase, controlled studies are needed to assess the role of PCV-7. OBJECTIVE:
To examine the association of PCV-7 vaccination and nasopharyngeal acquisition of serotype 19A pneumococci, their clonal distribution, and antibiotic susceptibility. DESIGN, SETTING, AND PATIENTS Post hoc per-protocol completer's analysis as part of a randomized controlled trial of nasopharyngeal Streptococcus pneumoniae carriage enrolling 1003 healthy newborns with follow-up to the age of 24 months in The Netherlands, which has low antibiotic resistance rates. The study was conducted before widespread PCV-7 implementation in infants, between July 7, 2005, and February 14, 2008. Nasopharyngeal swabs were obtained at the age of 6 weeks and at 6, 12, 18, and 24 months. INTERVENTION Infants were randomly assigned to receive 2 doses of PCV-7 at 2 and 4 months; 2 + 1 doses of PCV-7 at 2, 4, and 11 months; or no dosage (unvaccinated control group). MAIN OUTCOMEMEASURE:
Cumulative proportion of children with nasopharyngeal acquisition of a new serotype 19A strain from 6 through 24 months of age.RESULTS:
Nine hundred forty-eight children completed the study. Fifty-four nasopharyngeal serotype 19A carriage isolates from 318 in the 2-dose group, 66 isolates from 327 in the 2 + 1-dose group, and 33 isolates from 303 in the unvaccinated were collected from 6 weeks through 24 months. The cumulative proportion who tested positive for new nasopharyngeal serotype 19A acquisition from 6 through 24 months of age was significantly higher in those having received the 2 + 1-dose PCV-7 schedule (16.2%; 95% confidence interval [CI], 12.6%-20.6%) vs those who were unvaccinated (9.2%; 95% CI, 6.5%-13.0%; relative risk [RR], 1.75; 95% CI, 1.14-2.70) but not after a 2-dose schedule (13.2%; 95% CI, 9.9%-17.4%; RR, 1.43; 95% CI, 0.91-2.25). There were 28 different sequence types identified, including 6 new types. The proportion of children with new 19A acquisition who had used antibiotics in the last 6 months (18.7%) did not differ among groups. Five isolates were penicillin-intermediate susceptible and another 3 were nonsusceptible to erythromycin and azithromycin, all in the vaccine groups.CONCLUSION:
A 2 + 1-dose PCV-7 schedule was associated with an increase in serotype 19A nasopharyngeal acquisition compared with unvaccinated controls. TRIAL REGISTRATION clinicaltrials.gov Identifier NCT00189020.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Infecções Pneumocócicas
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Streptococcus pneumoniae
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Portador Sadio
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Vacinas Pneumocócicas
Tipo de estudo:
Clinical_trials
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Etiology_studies
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Guideline
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Female
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Humans
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Infant
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Male
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Newborn
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article