Following the introduction of pneumococcal conjugate vaccine 13 (PCV13), a decline in invasive pneumococcal disease (IPD) due to serotypes 19A and 7F 19A -- without an increase in nonvaccine serotypes (NVST) disease -- was observed in children under two and between two and five years of age, resulting in the lowest observed incidence of IPD since the introduction of Haemophilus influenzae type b vaccine.
Stephen I. Pelton, MD, of the Boston University School of Medicine, Boston, and colleagues collected data following the introduction of PCV13 for universal immunization through age five in April 2010. They found that the incidence of IPD in children under five was 8.3 per 100,000, a 58% decline from the eight-year mean (19.9) seen from 2001 to 2010. Comparable declines were observed in children under two (62%; 32.4 to 12.3/100,000) and from two to five years (56%; 12.9 to 5.6/100,000).
There was no change noted hin incidence regarding children five to 18 years. No cases of Streptococcus pneumoniae (SP) meningitis were observed in 2011-2012, compared with 1.4 /100,000 annual average between 2002 and 2010. According to Dr. Pelton and colleagues, IPD due to serotypes 19A and 7F dramatically declined; no increase in IPD due to nonvaccine serotypes (NVST) has been observed overall or for serotypes 22F and 15BC to date.