Pneumococcal Carriage in the Sahel Region of Burkina Faso before a 13-Valent Pneumococcal Conjugate Vaccination Campaign.

Abstract

Burkina Faso introduced 13-valent pneumococcal conjugate vaccine (PCV13) in 2013 and achieved >90% three-dose coverage. Recently, the Sahel Region has experienced a security crisis, resulting in decreasing PCV13 coverage. We examined pneumococcal carriage before a mass PCV13 campaign in the Sahel Region in 2022. In January and February 2022, we conducted a cross-sectional, age-stratified pneumococcal carriage study among healthy individuals in Dori, the capital of the Sahel Region. We collected nasopharyngeal (all participants) and oropharyngeal swabs (participants 5 years old and older). Pneumococci isolated by culture were serotyped by polymerase chain reaction and/or Quellung. We evaluated overall and vaccine serotype pneumococcal carriage prevalence by age group. Among 1,079 participants, overall pneumococcal carriage prevalence was 57.2%; carriage was highest in children 1 year old (71.8%) and 1-11 months old (69.7%) and lowest in participants 15 years old or older (30.0%). Vaccine serotype carriage prevalence was 12.8%, ranging from 5.6% in participants 15 years old or older to 17.8% in children 5-14 years old. PCV13 vaccination history was unknown for 59.6% of age-eligible children. Among children with card-confirmed or verbally reported PCV13 history, most (99.0%) had no history of PCV13 receipt. Eight years after PCV13 introduction and in a conflict-affected area with declining PCV13 coverage, more than 1 in 10 children and 1 in 20 participants 15 years old or older are colonized with a vaccine serotype. These results will be used to evaluate the mass PCV13 campaign impact and help inform policy surrounding pneumococcal conjugate vaccine use during humanitarian crises.