Measuring the effects of pneumococcal conjugate vaccine (PCV7) on Streptococcus pneumoniae carriage and antibiotic resistance: The Palestinian-Israeli Collaborative Research (PICR)

The unique study design distinguishes secular and seasonal effects from true vaccine effects. While PCV7 did not affect overall pneumococcal carriage rate, VT7 strains, many of which were antibiotic resistant decreased and were replaced by non-VT13 strains, which were mostly not antibiotic resistant, resulting in a net decrease in antibiotic resistance.