Nasopharyngeal Carriage Study in Healthy Kenyan Toddlers
Condition: Pneumococcal Disease
MeSH terms: Pneumococcal Infections
Study type: Observational

Summary: 
      This study evaluated the change in nasopharyngeal carriage (NPC) of Streptococcus pneumoniae
      (SPn), hypothesizing that it would be reduced post-vaccination with Streptococcus pneumoniae
      whole cell vaccine with aluminum hydroxide adjuvant (PATH-wSP) and that PATH-wSP would remain
      safe and well-tolerated over the course of the study.
    

Detailed description: 
      This study enrolled healthy Kenyan toddlers (12-15 months of age) who participated in the
      randomized control trial of VAC-010 (NCT02097472), as well as healthy toddlers aged 12 to 15
      months who had not participated in the VAC-010 Study. All participants must have received a
      primary dose of pneumococcal conjugate vaccine (PCV) per local practice prior to enrollment
      in either VAC-010 or VAC-011. No treatments were administered during this study.

      The study consisted of the following four groups:

      Participants who were randomized in study VAC-010 (2:2:1 ratio), defined according to the
      treatment received in VAC-010:

        -  1. PATH-wSP + Booster

        -  2. PATH-wSP Only

        -  3. Booster Only

      Participants who did not participate in VAC-010:

        -  4. No Intervention

      Each group consisted of 2 cohorts of participants, Cohort 1 (300 µg PATH-wSP) and Cohort 2
      (600 µg PATH-wSP). Enrollment into Cohorts 1 and 2 occurred sequentially; participants in
      groups 3 and 4 who did not receive PATH-wSP were also enrolled over time and allocated into
      one of the two cohorts (300 and 600 µg) in order to control for potential seasonal variation
      in the NPC of S. pneumoniae.

      Each participant completed a total of 5 scheduled visits. For toddlers enrolled
      simultaneously in VAC-010, visits corresponded to enrollment (Baseline) and 4, 8, 12, and 24
      weeks post final vaccination in VAC-010. For toddlers in the No Intervention group, the first
      visit corresponded to Baseline and the second to fifth visits corresponded to 12, 16, 20, and
      32 weeks later. Nasopharyngeal swabs were taken at each visit following World Health
      Organization (WHO) guidelines for analysis of nasopharyngeal burden.

      Treatments received during VAC-010 included:

        -  PATH-wSP: Streptococcus pneumoniae whole cell vaccine with aluminum hydroxide adjuvant

        -  Synflorix™ booster vaccine: pneumococcal polysaccharide conjugate vaccine (adsorbed)

        -  Pentavac booster vaccine: diphtheria, tetanus, pertussis (Whole Cell), hepatitis B
           (recombinant deoxyribonucleic acid [rDNA]) and Haemophilus influenzae type b conjugate
           vaccine (adsorbed).

        -  Saline control
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Healthy PCV- primed Kenyan toddlers; some of whom have participated in VAC-010 (n=250) and
        some of whom have not (n=50)
      
Biospecimen description: 
      Nasal swab sample and blood draw