A longitudinal study of streptococcus pneumoniae carriage in healthy children in the 13-valent pneumococcal conjugate vaccine era.
Hum Vaccin Immunother
; 11(4): 811-7, 2015.
Article
in En
| MEDLINE
| ID: mdl-25751237
ABSTRACT
Few epidemiological data are available after the introduction of the 13-valent pneumococcal vaccine (PCV13) in 2010. We performed repeat nasopharyngeal swabs and evaluated the serotype distribution of Streptococcus pneumoniae (SP) and its association with PCV13 vaccine status in healthy Italian children aged 3-59 months. SP serotypes were assessed by the Quellung reaction. 618 children appropriately (28%) or incompletely (72%) vaccinated for age with PCV13 were available at baseline (T0). 515 were re-evaluated at 6 months from baseline (T6) and 436 at 12 months from baseline (T12). The percentage of appropriately vaccinated subjects at T0, T6 and T12 was 28%, 67% and 92%, respectively. Random effects logistic regression models with robust 95% confidence intervals was used to estimate the time-related changes in SP and PCV13 carriage and marginal probabilities were obtained from such models. The age-corrected probability of SP carriage was 0.31 (95% CI 0.22 - 0.41) at T0, 0.32 (0.24 - 0.40) at T6 and 0.28 (0.20 - 0.35) at T12. The probability of PCV13 serotypes carriage was 0.025 (0.001 - 0.050) at T0, 0.018 (0.001 - 0.039) at T6 and 0.010 (0.001 - 0.023) at T12. A decrease in PCV13 serotypes and a shift in non-PCV13 serotypes colonization was observed. In particular, the 15A serotype accounted for 4%, 8% and 23% of SP isolates at T0, T6 and T12, respectively. In conclusion, the benefits of the PCV13 vaccination on SP carriage increase with increasing coverage rates. The shift of SP isolates toward non-PCV13 serotypes needs to be studied further.
Key words
13-valent pneumococcal conjugate vaccine; CI, confidence interval; IPD, invasive pneumococcal disease; MAR, missing at random; N, number; OR, odds ratio; PCV13, pneumococcal 13-valent vaccine; PCV7, pneumococcal 7-valent vaccine; SP, Streptococcus pneumoniae; Streptococcus pneumoniae; VT, vaccine type; children; cohort study; epidemiology; nasopharyngeal carriage
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pneumococcal Infections
/
Vaccines, Conjugate
/
Pneumococcal Vaccines
Type of study:
Observational_studies
/
Risk_factors_studies
Limits:
Child, preschool
/
Female
/
Humans
/
Infant
/
Male
/
Newborn
Language:
En
Journal:
Hum Vaccin Immunother
Year:
2015
Document type:
Article
Affiliation country:
Italy