SAN FRANCISCO, Oct. 25 (UPI) -- The incidence of pneumonia and meningitis -- the most common invasive bacterial infections in young children -- was cut by nearly 90 percent by promoting use of a new vaccine to control the diseases.
Although only about 58 percent of the children under one year of age received any injections -- and a mere 16 percent were fully vaccinated -- there was an 87 percent overall reduction in the infections, said Dr. Steven Black, co-director of the Kaiser Permanente Vaccine Study Center, Oakland, Calif.
"We think we are seeing a herd immunity effect," Dr. Black told United Press International, "in that vaccinated kids are also protecting those who have not been vaccinated, because they're exposed less often to the bacteria. As the vast majority of infants and toddlers are vaccinated, we expect the incidence of invasive pneumococcal disease to continue to decline."
But just because those children are getting vaccinated there is no safety in not having a child inoculated against the diseases which kill 200 children, most under the age of two, each year.
"About 97 percent of children who were vaccinated are protected by the vaccine," Black said. "The vast majority of the children still developing pneumonia and meningitis are those who have not been vaccinated. Not getting a child vaccinated is like playing Russian Roulette with their health."
Black and his co-director Dr. Henry Shinefield will report Saturday at the annual meeting of the Infectious Diseases Society of America on their experience in the vaccination program that involves 85,000 children.
They said the rate of infection in children less than 2 years old decreased from a historically-anticipated rate of 80 to 120 cases per 100,000 children to 25-40 cases per 100,000. In children under 1 year, the anticipated rate would have been 55 to 100 cases and that was reduced to 10 cases per 100,000.
In the group of children under age 5, the expected 40-60 cases per 100,000 was reduced to less than 20 cases per 100,000.
Shinefield suggested that some evidence also indicates that by inoculating children, the "herd protection" accrues to adults as well. With fewer children bringing home bacterial infections from day care centers, there are fewer infections that can be spread in the home. "There appears to be a very profound protector effect," he said.
"Those are exciting figures," said Dr. Craig Smith, an infectious disease specialist in Albany. Ga. "We have come to expect that vaccination programs can effect even those who are not inoculated. However, I don't think you would see that in every population study."
Smith said that pneumococcal infections are especially troubling to doctors because the presentation of pneumonia and meningitis are similar. When a child appears with fever doctors don't know if that will become a routine case or develop into a potentially fatal or brain-damaging situation.
If the vaccine eliminates these infections, Black said, no doctor will complain about loss of patients.
"These are the cases we lose sleep over. these cases are hard to diagnose. Doctors won't mind losing this kind of business," he said.
