Vaccine reduces bloodstream infections by nearly 60%.(Brief Article)

2002 MAR 13 - (NewsRx.com & NewsRx.net) -- A single injection of a first-of-its-kind experimental vaccine, Nabi StaphVAX (Staphylococcus aureus polysaccharide conjugate vaccine), reduced bloodstream infections caused by the often drug-resistant and potentially deadly bacteria, S. aureus, in end-stage kidney disease patients by nearly 60%, according to a Phase III study that appears in the February 14, 2002, issue of the New England Journal of Medicine.

The study was conducted by investigators from Kaiser Permanente in collaboration with scientists at the National Institutes of Health (NIH) and at Nabi Corp. (NABI).

S. aureus is a major cause of hospital-acquired infections, including bloodstream infections, or bacteremias. Community-acquired staph infections are also of growing concern. "Staph is one of the most frequent and potentially deadly bacterial infections in hospitals today. Now, for the first time, an experimental vaccine has been shown to reduce the incidence of bloodstream infections caused by this bacteria," said coauthor Robert Naso, PhD, senior vice president of quality, regulatory and product development at Nabi, the biopharmaceutical company that is developing the vaccine and supported the study.

After just one injection, StaphVAX reduced the incidence of systemic S. aureus infection in the blood by 57%, through 40 weeks of the 54 week study. By the end of the study, 86% of the patients had responded to the candidate vaccine with high levels of specific antibody.

"Kidney disease patients on hemodialysis are among the least likely to respond to a vaccine because their immune systems are generally compromised. Based upon previous clinical studies in normal, healthy volunteers, we believe that other patient populations at risk for staph infections will respond to the vaccine with even higher levels of antibodies than was achievable in kidney disease patients," Naso said.

Hospitals and other health care settings worldwide face unprecedented crises from the rapid emergence and dissemination of antibiotic-resistant bacteria, according to the NIH. Strains of drug-resistant S. aureus are found in most hospitals, often leaving vancomycin as the antibiotic of last resort for treating patients with these infections. With vancomycin-resistant strains of staph now appearing, many experts believe that a vaccine to prevent these infections may offer the best long-term solution.

According to the U.S. Centers for Disease Control and Prevention, more than 2 million patients in the U.S. each year contract an infection as a result of exposure while receiving health care in a hospital. S. aureus is among the most common causes of these hospital-acquired infections and is reportedly associated with a mortality rate of 10-25% because of its capacity to cause serious complications. S. aureus can spread from the blood (bacteremia), to the bones (osteomyelitis), or the inner lining of the heart and its valves (endocarditis), or cause abscesses in internal organs such as the lungs and kidneys. Most at risk for these infections are surgical patients, trauma or burn victims, newborns whose immune systems are not yet developed and people with such chronic illnesses as diabetes, cancer or lung or kidney diseases. People whose immune systems are suppressed due to disease, drugs or radiation therapy also are more susceptible to these bacterial infections.