Vaccine trial shows promising results for streptococcal infection protection

A study published in the current issue of JAMA reports that a streptococcal vaccine trial has shown promising results for protection against streptococcal infections.

Streptococcal infections are caused by group A streptococcus, a bacterium responsible for a variety of health problems. These infections can range from mild skin infection or sore throat to invasive, life-threatening conditions such as toxic shock syndrome and necrotizing fasciitis. Most people are familiar with strep throat, which along with minor skin infection, is the most common form of the disease. Experts estimate that more than 10 million mild infections like these occur every year.

Efforts to develop a vaccine to prevent group A streptococcal (a type of bacteria that commonly causes illness) infections have been ongoing for more than 70 years, according to background information in the article. Recent advances have allowed previous obstacles associated with group A streptococcal vaccine development to be overcome. Group A streptococcal infections and their sequelae represent a global health problem.

Karen L. Kotloff, M.D., of the University of Maryland School of Medicine, Baltimore, and colleagues report on a preliminary study evaluating the safety and immune reactivity of a group A streptococcal vaccine in healthy volunteers. The phase 1 vaccine trial included 28 adult volunteers aged 18 to 50 years recruited from the metropolitan area of Baltimore between October 1999 and February 2003. Each volunteer received 3 spaced intramuscular injections of either 50 micrograms (n=8), 100 micrograms (n=10), or 200 micrograms (n=10) of group A streptococcal vaccine formulated with aluminum hydroxide into the deltoid muscle of alternating arms.

"Our findings, albeit in a small number of participants, suggest that in the full dose range tested, the vaccine appears safe and well tolerated and does not evoke antibodies that cross-react with human tissue. We have identified a dose (200 micrograms) and schedule (0, 28, and 112 days) that appears to be capable of inducing immune responses... that are likely to confer protection against multiple group A streptococcal M types."