Introduction and Proliferation of Multidrug‐ResistantStreptococcus pneumoniaeSerotype 19A Clones That Cause Acute Otitis Media in an Unvaccinated Population

Introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) in the United States in 2000 was temporally associated with an increase in the incidence of disease caused by Streptococcus pneumoniae serotype 19A (Sp19A) and with increasing drug resistance within this serotype. A causative role of PCV7 was speculated. We prospectively studied the dynamics of acute otitis media (AOM) caused by Sp19A in southern Israel before the introduction of...