E W. Kagucia, Kenya
KEMRI-Wellcome Trust Research Programme Epidemiology and DemographyPresenter of 1 Presentation
LONG-TERM TRENDS IN NASOPHARYNGEAL CARRIAGE OF VACCINE-TYPE PNEUMOCOCCI: FINDINGS FROM A MATURE 10-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV10) PROGRAM IN KENYA (ID 966)
Abstract
Background
PCV10 was introduced into Kenya’s immunization program in 2011, with catchup in children aged 1-4 years. We evaluated the long-term effect of PCV10 on nasopharyngeal carriage of Streptococcus pneumoniae serotypes included in PCV10.
Methods
Population-based annual cross-sectional nasopharyngeal carriage surveys were conducted in randomly selected individuals between 2009 and 2019 (N= ~1000 in 2019; N= ~500 in all others) in Kilifi, Kenya. Pneumococcal identification was performed per WHO standards. Annual vaccine-type carriage prevalence was modelled using log-binomial regression with a curved function for year and adjustment for age-specific sampling probability.
Results
Compared to 2010, carriage of PCV10-type pneumococci declined significantly through 2019 in children aged <5 years to 6.1% (adjusted prevalence ratio 0.18, 95%CI 0.11-0.30) but not in children aged 5-14 years (prevalence= 7.1%; 0.71, 0.38-1.34) nor adults ≥15 years (prevalence= 1.0%; 0.49, 0.17-1.35). PCV10-type carriage was significantly lower in 2017 compared to 2010 for all age groups and did not differ from carriage prevalence in 2019 (figure).
Conclusions
PCV10-type carriage prevalence appears to be approaching equilibrium, yet residual carriage persists. Virtual elimination of PCV10-type carriage (≤1% in children <5 years; ≤3% in children 5-9 years) – a prerequisite for introduction of reduced dose schedules – is unlikely without implementation of additional strategies.
Author Of 1 Presentation
LONG-TERM TRENDS IN NASOPHARYNGEAL CARRIAGE OF VACCINE-TYPE PNEUMOCOCCI: FINDINGS FROM A MATURE 10-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV10) PROGRAM IN KENYA (ID 966)
Abstract
Background
PCV10 was introduced into Kenya’s immunization program in 2011, with catchup in children aged 1-4 years. We evaluated the long-term effect of PCV10 on nasopharyngeal carriage of Streptococcus pneumoniae serotypes included in PCV10.
Methods
Population-based annual cross-sectional nasopharyngeal carriage surveys were conducted in randomly selected individuals between 2009 and 2019 (N= ~1000 in 2019; N= ~500 in all others) in Kilifi, Kenya. Pneumococcal identification was performed per WHO standards. Annual vaccine-type carriage prevalence was modelled using log-binomial regression with a curved function for year and adjustment for age-specific sampling probability.
Results
Compared to 2010, carriage of PCV10-type pneumococci declined significantly through 2019 in children aged <5 years to 6.1% (adjusted prevalence ratio 0.18, 95%CI 0.11-0.30) but not in children aged 5-14 years (prevalence= 7.1%; 0.71, 0.38-1.34) nor adults ≥15 years (prevalence= 1.0%; 0.49, 0.17-1.35). PCV10-type carriage was significantly lower in 2017 compared to 2010 for all age groups and did not differ from carriage prevalence in 2019 (figure).
Conclusions
PCV10-type carriage prevalence appears to be approaching equilibrium, yet residual carriage persists. Virtual elimination of PCV10-type carriage (≤1% in children <5 years; ≤3% in children 5-9 years) – a prerequisite for introduction of reduced dose schedules – is unlikely without implementation of additional strategies.