Posted on Tue, Feb. 12, 2002

Vaccine Against Staph Infection Shows Promise
BY AMY NORTON

NEW YORK - (Reuters Health) - An experimental vaccine against the potentially deadly bacterium Staphylococcus aureus has been found to offer partial protection in patients with advanced kidney failure, a group at particular risk of serious infections.

Although the immunity was only temporary--lasting about 40 weeks--researchers say their findings are an encouraging first step.

Staph infections are common and often minor, causing problems such as pimples and other skin conditions. But the bacteria can also spread to the blood and cause serious infections of the bone, heart and other tissue. Staph infection is a major cause of hospital-acquired illnesses, and hospitalized patients with compromised immune systems are at particular risk--including kidney patients on hemodialysis.

The new study followed more than 1,800 kidney failure patients at California hemodialysis centers, about half of whom received an experimental Staph vaccine. The rest were given an inactive placebo.

In the first 40 weeks afterward, the vaccine cut the incidence of Staph blood infections by 57%, according to findings published in the February 14th issue of The New England Journal of Medicine. Twenty-six of 906 placebo patients developed infections, compared with 11 of 892 vaccinated patients.

But the protection waned thereafter in the 54-week study, as patients' blood levels of Staph antibodies declined.

Still, ``40 weeks is encouraging'' when it comes to offering Staph protection to these high-risk patients, the study's lead author told Reuters Health.

``These are the patients least likely to respond well to a vaccine,'' said Dr. Henry Shinefield of the Kaiser Permanente Vaccine Study Center in Oakland, California.

The goal of Staph vaccination is to prevent the serious infections that threaten certain groups of people in and out of the hospital, according to Shinefield. He noted that even a vaccine that can offer 40 weeks of immunity could be useful, for example, when given to high-risk patients a few weeks before they enter the hospital for surgery.

A Staph vaccine might also protect high-risk people in the community--such as diabetics with nerve damage, who are at risk of wound infections. Shinefield said that booster shots might improve the vaccine efficacy in such individuals. Further research, he noted, will look into using booster doses.

``This is only a first step,'' Shinefield said.

Several co-authors on the study are with the Florida-based pharmaceutical company Nabi, which developed the vaccine and funded the research.

SOURCE: The New England Journal of Medicine 2002;346:491-496.