Effect of Haemophilus influenzae type b and 13-valent pneumococcal conjugate vaccines on childhood pneumonia hospitalizations and deaths in Botswana.

BACKGROUND Globally, pneumonia is the leading cause of death among children. Few data exist regarding the effect of Haemophilus influenzae type b (Hib) vaccine and 13-valent pneumococcal conjugate vaccine (PCV-13) on the burden of childhood pneumonia in African settings. METHODS We collected data on children 1 to 59 months of age at three hospitals in Botswana. Hib vaccine and PCV-13 were introduced in Botswana in November 2010 and July 2012, respectively. We compared pneumonia hospitalizations and deaths pre-vaccine (January 2009 to October 2010) to post-vaccine (January 2013 to December 2017) using seasonally-adjusted interrupted time-series analyses. FINDINGS We identified 6943 pneumonia hospitalizations and 201 pneumonia deaths. In the pre-vaccine period, pneumonia hospitalizations and deaths increased by 24% (rate: 1.24; 95% CI: 0.94, 1.64) and 59% (rate: 1.59; 95% CI: 0.87, 2.90) per year, respectively. Vaccine introduction was associated with a 48% (95% CI: 29%, 62%) decrease in the number of pneumonia hospitalizations and a 50% (95% CI: 1%, 75%) decrease in the number of pneumonia deaths between the end of the pre-vaccine period (October 2010) and the beginning of the post-vaccine period (January 2013). During the post-vaccine period, pneumonia hospitalizations and deaths declined by 6% (rate 0.94; 95% CI: 0.89, 0.99) and 22% (rate: 0.78; 95% CI: 0.67, 0.92) per year, respectively. INTERPRETATION Pneumonia hospitalizations and deaths among children declined sharply following introduction of Hib vaccine and PCV-13 in Botswana. This effect was sustained for more than five years after vaccine introduction, supporting the long-term effectiveness of these vaccines in preventing childhood pneumonia in Botswana.