The introduction of the 13-valent pneumococcal conjugate vaccine has led to a significant decrease in the incidence of invasive pneumococcal disease in the general pediatric population but with a trend toward increasing incidence, particularly of nonvaccine serotypes, among children with comorbidities.
A study of Massachusetts public health surveillance data from before and after the introduction of the 13-valent vaccine (PCV13) showed a 49% decrease (168 vs. 85) in the absolute number of invasive pneumococcal disease cases in children aged under 5 years but a 17% increase in the proportion of cases in children with comorbidities such as chronic lung disease, malignancy, or immunosuppressive therapy. These changes are not considered statistically significant.
"Routine vaccination with PCV13 may not be sufficient to reduce the risk of invasive disease in patients with comorbidity, and administering 23-valent pneumococcal polysaccharide vaccine to all children with comorbidity at the earliest acceptable age should be considered," wrote Dr. Pui-Ying Iroh Tam of the University of Minnesota Children’s Hospital, Minneapolis, and colleagues.
The prevalence of vaccine serotypes declined significantly (18%) in the first 2 years after introduction of PCV13, although serotype 19A remained the most common serotype even after the introduction of the vaccine, despite a significant decline in its prevalence, as reported online in the July 7 edition of Pediatrics (Pediatrics 2014 July 7 [doi: 10.1542/peds.2014-0473]).
The study was funded by the National Institutes of Health. One author received investigator-initiated grants from Pfizer for the study, while another author declared honoraria and grants from various pharmaceutical companies.