T O R O N T O, Sept. 19, 2000 -- A vaccine has been shown for the first time toprotect against life-threatening staph infections, a major hazardamong hospital patients, researchers said today.
The genetically engineered vaccine was tested first in kidneydialysis patients, and it cut their risk of staph blood poisoningin half for nearly a year.
“I am quite encouraged by this. It could be a majorbreakthrough in this area,” said Dr. Steve Black of the KaiserPermanente Vaccine Study Center in Oakland, Calif.
Black presented the results in a last-minute addition to theprogram of the annual infectious disease meeting of the AmericanSociety for Microbiology.
The vaccine, called StaphVAX, was created at the NationalInstitutes of Health and is being developed by Nabi Corp. of BocaRaton, Fla., which financed the latest study.
Staphylococcus aureus is a common and ordinarily harmlessinhabitant of the human nasal tract. It can live for days outsidethe body on almost any surface and spreads widely in hospitals,where it can cause serious infections among those who are alreadysick, especially if they have weak immune defenses.
Infection Sometimes Fatal
Staph can be deadly if it invades the bloodstream. It can leadto pneumonia, encephalitis, liver abscesses and other problems.
Staph infections are relatively common among people who useneedles frequently, such as diabetics and dialysis patients,elderly people in nursing homes and those who are hospitalized forsurgery and a variety of other conditions.
Doctors conducted the first large test of StaphVAX in dialysispatients because typically between 1 percent and 3 percent of themget bloodstream staph infections each year.
Robert B. Naso, Nabi’s research director, said the company willseek approval soon from the U.S. Food and Drug Administration toproduce and sell the vaccine.
The study enrolled 1,804 patients at 90 dialysis centers inCalifornia. Half got the vaccine, while the rest took dummy shots.
The vaccine appeared to quickly lower the risk of staph. After10 months, there were 11 serious infections among those getting thevaccine, compared with 26 in the unprotected group, a 57 percentreduction.
The vaccine triggers the body to make fresh antibodies againststaph. After one year, the patients’ antibody levels dropped, andtheir 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 anespecially difficult problem for dialysis patients.
A Growing Immunity to Antibiotics
“If you can get this much protection in them, it might workeven better in other patients,” she said.
Staph infections are of particular concern because the bacteriais growing immune to the antibiotics commonly used to treat it.Half of all staph that circulates in hospitals is resistant tomethicillin, the standard drug. Now it is developing resistance tovancomycin, the main backup drug.
Black said the new vaccine could be given to build up staphresistance in surgery patients, who are prone to the infection. Itmight also be used in nursing homes, among diabetes patients and inpeople who are hospitalized for a variety of problems.
He said researchers will also probably explore the possibilityof giving booster doses to people who must keep up resistance for along time, such as those on dialysis.
Black said that until researchers began analyzing their resultslast week, there was no clear evidence that boosting staphantibodies would have any effect on serious infections. Virtuallyeverybody has some staph antibodies, since the bacteria are socommon.