Feb. 13, 2002 -- People with weakened immune systems are susceptible to attack by Staphylococcus aureus bacteria. But a newly developed vaccine may soon protect hospitalized children, kidney dialysis patients, and other vulnerable populations from potentially deadly staph infections.
The nasty S. aureus bugs cause a host of problems -- from skin infections to life-threatening meningitis. And to make matters worse, some mutated strains can now withstand our most powerful antibiotics.
"Staphylococcus aureus bacteria can be life-threatening and are rapidly growing resistant to the antibiotics used to treat them," says Duane Alexander, MD, director of the National Institute of Child Health and Human Development. "This new vaccine may provide a powerful new way to prevent the thousands of serious S. aureus infections that occur each year.
Over the past 15 years, John Robbins, MD, chief of NICHD's Laboratory of Developmental and Molecular Immunity, and colleagues methodically uncovered just how the bacteria successfully sidesteps a host's immune system to establish infection. Now, his team has used the information against the bug to develop an effective vaccine.
In the trial reported in the Feb. 14 issue of The New England Journal of Medicine, they randomly assigned nearly 1,800 dialysis patients to receive either the vaccine or a harmless saline solution. Soon, the incidence of a particular staph infection called bacteremia began to fall in the vaccine group, but not in the saline group. When they checked each vaccinated patient's blood, they saw antibodies to S. aureus -- a sure sign that they could fight off an attack.
Antibody levels did begin falling after about the 40th week, however, which is not unusual in dialysis patients. The researchers are now looking at whether a booster dose of the vaccine will help keep antibody levels high.
"It is likely that the vaccine will be more effective in individuals with less depressed immune systems who are at risk for S. aureus infections, such as patients with chest and cardiac surgery and with joint replacements," Robbins said.