Streptococcus pneumoniae is a bacterium associated with a large percentage of ear infections, meningitis, pneumonia, and bacteremia in children, and invasive disease in elderly adults.
At least 90 serotypes of pneumococcal bacterium are known, and up to one third of all U.S. types demonstrate moderate to high-level resistance to antibiotics.
A conjugate vaccine that contains the seven serotypes responsible for 80% of invasive disease was licensed in 2000 for use in infants and children, and is now recommended for use in all infants. (CDC, 2000).
The vaccine is relatively ineffective in adults (it does not prevent pneumonia), but is effective in preventing pneumonia and other invasive disease in children.
The Vaccine Guide: Risks and Benefits for Children and Adults, Randall Neustaedter, OMD
The vaccine does not prevent ear infections (See Prevnar Product Insert).
The widespread use of vaccine may cause shifts in disease pathogens to serotypes not contained in the currently licensed vaccine, thus leaving the overall incidence of problems caused by the bacterial group relatively unchanged (See Prevnar Product Insert).
This is exactly what has happened. Therefore the original pneumococcal vaccine Prevnar has been replaced by Prevnar 13.