Vaccinating Kids Cuts Adult Pneumonia
Giving Pneumonia Vaccine to Kids Cuts Child, Adult Disease
April 30, 2003 -- Pneumonia vaccine protects kids. Giving it to kids also seems to protect their parents and grandparents, new data suggest.
There are two pneumonia vaccines. Both fight the strep bacteria that are a leading cause of pneumonia. Neither one works against viruses that cause pneumonia. The children's' vaccine, called the conjugate vaccine, targets the seven types of strep most common in U.S. kids. The adult vaccine, called the polysaccharide or 23-valent vaccine, targets 23 types of the strep pneumonia bugs.
Both pneumonia vaccines are controversial. The conjugate pneumonia vaccine has doubled the price of childhood vaccination. The U.S. is the only nation to put it on every child's immunization schedule. Is it worth it? "Yes" seems the resounding answer. A new study shows that the vaccine delivers both the expected benefit and an extra bonus. The report, by Cynthia G. Whitney, MD, MPH, of the CDC's National Center for Infectious Diseases and colleagues, appears in the May 1 issue of The New England Journal of Medicine.
Whitney's team looked at pneumonia trends before and after the conjugate vaccine became available in early 2000. Even though a pneumonia vaccine shortage kept many children from getting all of their shots, the vaccine slashed pneumonia rates.
"As expected, it's doing a great job in protecting kids," Whitney tells WebMD. "And they are not transmitting the disease to adults, so adults are not getting infected as often. There's also been a decline in pneumonia due to antibiotic-resistant strains of bacteria."
In children under 2 years of age -- those who got the pneumonia vaccine -- the strep pneumonia rate dropped 69%. It also dropped by 32% in adults 20-39 years old and by 18% in adults age 65 and older. As many more children now get the vaccine, Whitney says she expects disease rates to drop even more.
"I don't think we are at the bottom yet," she says. "It's still early, and there are so many vaccinated children out there. My feeling is that we will see more of this effect."
The decrease in adult pneumonia isn't proof that childhood vaccination cuts disease in adults, warns Keith Klugman, MD, PhD, professor of medicine at Atlanta's Emory School of Medicine and professor of international health at Emory's Rollins School of Public Health. But he says it's an idea that's getting serious attention from public health experts.
"This is quite novel, the idea you could immunize children to protect adults," Klugman tells WebMD. "There is evidence from Japan that annual immunization of children with flu vaccine reduced flu mortality in adults. These sorts of observations are changing the equation of cost effectiveness of vaccination."
Why not just vaccinate adults? The older 23-valent vaccine is supposed to do just that. But another NEJM report shows that this vaccine doesn't cut pneumonia rates in elderly people. It does, however, keep the pneumonia bugs from causing deadly blood infections. Study leader Lisa A. Jackson, MD, MPH, is a researcher at Seattle's Group Health Cooperative and professor of epidemiology at the University of Washington, Seattle.