Pneumococcus is a common cause of infectious diseases, including pneumonia, in children. Pneumococcal conjugate vaccines were introduced into the Israeli national immunization program, starting with the heptavalent (PCV7) vaccine in 2009, and then the 13-valent (PCV13) vaccine in late 2010. The objective of this study was to determine how the vaccines affected hospitalization rates for community-acquired pneumonia (CAP), their impact on the severity of CAP and any subsequent changes seen in pneumococcal serotype distribution.
We retrospectively reviewed children between the ages of 1 and 16 years who were admitted with pneumonia, to the Shaare Zedek Medical Center between the years 2006-2015. We compared demographic and clinical data over time.
We reviewed 1,375 cases of pneumonia, of whom 331 (24%) had pleural fluid. A gradual decline in pneumonia hospitalization rates was observed between 2006 (12.3%) and 2015 (5.6%). This began prior to the introduction of the vaccines, and continued unchanged after their introduction, hinting that the vaccine did not result in reduced hospitalization rates for pneumonia. The average age at hospitalization increased over the years, as did the average length of stay. Rates of hospitalizations for pneumonia with pleural fluid were significantly higher in the PCV7 period compared to the pre-PCV7 period and dropped again during the PCV13 period. The distribution of serotypes 14, 5 and 12F shifted, suggesting that although the PCV13 vaccine did not reduce overall hospitalization rates, it may have been responsible for a reduction in complicated pneumonia rates.
