Since April 2014, invasive pneumococcal disease incidence has increased substantially across North East England, United Kingdom, reversing the decline that followed the 2006 introduction of pneumococcal conjugate vaccines. Significant increases occurred in 23-valent polysaccharide vaccine serotypes and nonvaccine serotypes. Trends in other regions and long-term effects of multivalent vaccines require further investigation.
Keywords: England; PCV13 vaccine; Streptococcus pneumoniae; United Kingdom; bacteria; incidence; invasive pneumococcal disease; pneumococcal infections; pneumococcal polysaccharide vaccine; vaccines.