HealthDay News — In preventing hospitalizations of younger children for pneumonia, a new pneumococcal vaccine is almost 30% more effective than its previous version, according to research published by the United States Centers for Disease Control and Prevention in Morbidity and Mortality Weekly Report.

The 13-valent pneumococcal conjugate vaccine protects against 13 strains of pneumococcal bacteria, which is the leading cause of pneumonia in children aged less than five years, explained Marie Griffin, MD, of Vanderbilt University in Nashville, Tenn., and colleagues.

Introduced in 2010, the new vaccine improved upon a seven-strain version that had been used since 2000. The introduction of that vaccine led to a 43% decline in childhood hospitalizations for pneumonia, according to the agency.

To analyze pneumonia hospitalizations in children, the investigators based their study off of Tennessee data, which they were able to obtain more quickly than national data. Pneumonia hospitalizations in Tennessee are now estimated at four out of every 1,000 children aged less than two years, a “historically lower rate that represents a 72% decline” from the prior to the introduction of the first vaccine in 2000.

Pediatric patients in Tennessee aged less than two years experienced about 1,300 fewer pneumonia hospitalizations annually in 2011 and 2012 compared with the years prior to pneumococcal vaccine adoption in 2000.

“The causes and appropriate treatment of childhood pneumonia in the era of PCVs needs to be continually assessed because the distribution of bacterial and other causes of pneumonia will likely change,” added the agency.