New Vaccine for Staph Infections
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
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
"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.