T O R O N T O, Sept. 19, 2000 -- A vaccine has been shown for the first time to protect against life-threatening staph infections, a major hazard among hospital patients, researchers said today.
The genetically engineered vaccine was tested first in kidney dialysis patients, and it cut their risk of staph blood poisoning in half for nearly a year.
“I am quite encouraged by this. It could be a major breakthrough in this area,” said Dr. Steve Black of the Kaiser Permanente Vaccine Study Center in Oakland, Calif.
Black presented the results in a last-minute addition to the program of the annual infectious disease meeting of the American Society for Microbiology.
The vaccine, called StaphVAX, was created at the National Institutes of Health and is being developed by Nabi Corp. of Boca Raton, Fla., which financed the latest study.
Staphylococcus aureus is a common and ordinarily harmless inhabitant of the human nasal tract. It can live for days outside the body on almost any surface and spreads widely in hospitals, where it can cause serious infections among those who are already sick, especially if they have weak immune defenses.
Infection Sometimes Fatal
Staph can be deadly if it invades the bloodstream. It can lead to pneumonia, encephalitis, liver abscesses and other problems.
Staph infections are relatively common among people who use needles frequently, such as diabetics and dialysis patients, elderly people in nursing homes and those who are hospitalized for surgery and a variety of other conditions.
Doctors conducted the first large test of StaphVAX in dialysis patients because typically between 1 percent and 3 percent of them get bloodstream staph infections each year.
Robert B. Naso, Nabi’s research director, said the company will seek approval soon from the U.S. Food and Drug Administration to produce and sell the vaccine.
The study enrolled 1,804 patients at 90 dialysis centers in California. Half got the vaccine, while the rest took dummy shots.
The vaccine appeared to quickly lower the risk of staph. After 10 months, there were 11 serious infections among those getting the vaccine, compared with 26 in the unprotected group, a 57 percent reduction.
The vaccine triggers the body to make fresh antibodies against staph. After one year, the patients’ antibody levels dropped, and their protection against staph began to fade.
Dr. Julie Gerberding, head of hospital infections at the U.S. Centers for Disease Control and Prevention, noted that staph is an especially difficult problem for dialysis patients.
A Growing Immunity to Antibiotics
“If you can get this much protection in them, it might work even better in other patients,” she said.
Staph infections are of particular concern because the bacteria is growing immune to the antibiotics commonly used to treat it. Half of all staph that circulates in hospitals is resistant to methicillin, the standard drug. Now it is developing resistance to vancomycin, the main backup drug.
Black said the new vaccine could be given to build up staph resistance in surgery patients, who are prone to the infection. It might also be used in nursing homes, among diabetes patients and in people who are hospitalized for a variety of problems.
He said researchers will also probably explore the possibility of giving booster doses to people who must keep up resistance for a long time, such as those on dialysis.
Black said that until researchers began analyzing their results last week, there was no clear evidence that boosting staph antibodies would have any effect on serious infections. Virtually everybody has some staph antibodies, since the bacteria are so common.