A University of Michigan-led study, published in Pediatrics, found children's doctors harbored concerns about the cost of the vaccine. Some pediatricians are recommending some parents pay out of pocket for the shots or go to a free clinic.
Prevnar prevents infections by Streptococcus pneumoniae bacteria that cause tens of thousands of potentially deadly bacterial meningitis and bloodstream infections each year, and untold millions of painful ear infections, the study said.
The Centers for Disease Control in Atlanta said 41 percent of children under age 3 had at least three doses of the vaccine by 2002.
"Historically, vaccines have been inexpensive and physicians have been willing to absorb the cost of stocking them or even providing them to underinsured patients," lead author Matthew M. Davis of the U-M Medical School said in a statement.