Pneumonia Vaccine Brings New Challenge
Vaccine's Success May Lead to Rise in Pneumonia Caused by Other Bacteria
April 24, 2007 -- The success of the pneumonia vaccine in children may allow
a rise in kids' pneumonia caused by germs not targeted by the vaccine.
That's according to researchers including the CDC's Rosalyn Singleton, MD,
In The Journal of the American Medical Association, Singleton's team
recommends monitoring children's pneumonia and updating pneumococcal disease
vaccines as needed.
Journal editorialists agree. They call the children's pneumococcal vaccine
"a towering success" but add that "the target is moving."
Pneumococcal Disease Vaccine
Pneumococcal diseases include life-threatening pneumonia and meningitis.
The CDC recommends the pneumococcal conjugate vaccine PCV7, given in four
doses, for all children who are less than 2 years old. Children aged 2-5 can
get catch-up doses of the vaccine.
The vaccine targets seven strains of Streptococcus pneumoniae
bacteria. Those strains are the leading causes of pneumococcal disease, but
other bacteria can also cause pneumonia.
Pneumococcal Vaccine Study
Singleton and colleagues studied Alaska Native children, who had high rates
of pneumococcal disease before the vaccine.
The researchers focused on children who were 19-35 months old between Sept.
30, 2003, and Sept. 30, 2006. The PCV7 vaccine was introduced to children's
routine immunization schedule in Alaska on Jan. 1, 2001.
As the vaccine became widely used, reported pneumococcal disease cases
caused by vaccine-targeted bacteria plummeted 67% in Alaska Native children
younger than 2 years old.
But at the same time, reported pneumococcal disease cases caused by other
nonvaccine strains of bacteria soared 82% in Alaska Native children less than 2
The study also shows that since 2004, the children had a 96% drop in
reported pneumococcal disease cases caused by vaccine-targeted bacteria. But
there was also a 140% rise in children's pneumococcal disease cases caused by
nonvaccine strains during the same time period.
The vaccine has been a "dramatic success," write Singleton and
colleagues. But they note that other strains of the bacteria not targeted by
the vaccine may be stepping up to fill the void.
It's not clear if the study's findings apply to children nationwide.
Singleton's team calls for ongoing monitoring of pneumococcal disease and the
development of expanded pneumococcal vaccines.
Meanwhile, the PCV7 vaccine is still effective against the bacteria it
targets, note Timothy Peters, MD, and Katherine Poehling, MD, MPH, in their
Peters and Poehling work at Brenner Children's Hospital at Wake Forest
University School of Medicine in Winston-Salem, N.C.