Researchers say an experimental vaccine appears to prevent child ear infection

From Medical Correspondent Rhonda Rowland

SAN DIEGO (CNN) -- In what some scientists call the most important public health advance for children during this decade, an experimental vaccine appears to prevent a type of ear infection that can lead to more serious complications.

Researchers from Kaiser Permanente unveiled the results of tests of an experimental vaccine, called PNCRM7, at a conference in San Diego. They say the vaccine, tested on almost 40,000 children, is effective in protecting children from a bacteria called pneumococcus, the most common cause of ear infections in children.

Pneumococcus infections can lead to meningitis and bacteremia, a severe bloodstream infection.

However, the vaccine is not a complete cure-all because it works on only seven types of pneumococcus; there are more than 80 strains of the bacteria. But the vaccine combats the most common types of pneumococcus, researchers say.

"Those seven types are responsible for about 85 percent of severe disease and about 65 percent of middle ear infections," said Dr. Margaret Rennells of the University of Maryland Medical Center. "So it will help enormously. But it's not going to eliminate all pneumococcal infections."

Researchers say the vaccine could be available for children in two to five years.