CHICAGO (AP) – Scientists say they are making headway in developing a vaccine against a common strep germ, the cause of millions of sore throats as well as a deadly but uncommon flesh-eating disease.

A test of an experimental vaccine in just 28 people prompted an immune response with no serious side effects, but it’s still not known if the shot would keep people from catching the strep germ.

Still, it was the first human testing of such a vaccine in almost 30 years, although at least two other vaccines are also under development.

Results of the federally funded study were reported in Wednesday’s Journal of the American Medical Association.

Safety concerns arising from previous, failed efforts discouraged research of the Group A type of streptococcus in humans, an endeavor that began in the 1930s. But the new vaccine – created through genetic engineering – does not include substances thought to have caused problems with earlier versions, said co-author Dr. James Dale of the University of Tennessee.

Dale invented the vaccine technology and is developing the vaccine with ID Biomedical Corp. Dale and two other co-authors – both IDB employees – own IDB stock.

The results are “a positive step in a long journey ahead” to develop a Group A strep vaccine, said Dr. Michael Pichichero, a vaccine expert at University of Rochester.

More studies with many more people are needed to prove that it will work and is safe, he said.

There are six different groups of strep, but Group A – the kind tested by the vaccine – is one of the most prevalent.

The bacteria, commonly found in the throat and on the skin, cause more than 10 million cases of strep throat and mild skin infections each year nationwide. Untreated strep throat can lead to rheumatic fever and potentially rheumatic heart disease, which affects an estimated 12 million people worldwide and kills about 400,000 each year, mostly in developing nations. Rheumatic fever has become uncommon in the United States with widespread use of antibiotics.

The rarest but most severe Group A ailments are necrotizing fasciitis – flesh-eating disease – and strep-linked toxic shock syndrome. There are about 9,000 annual cases of these invasive ailments nationwide.

“There is a need” for a Group A vaccine – in this country because of the financial burden of strep throat and the severity of invasive infections, and in developing countries because of rheumatic fever, said Dr. Chris Van Beneden of the federal Centers for Disease Control and Prevention.

Also, while invasive Group A diseases are uncommon in the United States, a shift toward severe infections including flesh-eating disease occurred in the 1980s and early 1990s. While overall rates since then have remained steady, they have not declined, Van Beneden said.

“What we don’t know is why there was a sudden increase of the more virulent strains, and it’s hard to predict when it might happen again,” she said.

Vaccines typically contain weakened or inactivated fragments of a germ that are strong enough to stimulate immunity, including the production of antibodies that attack the germs when a person is exposed to disease.

Another vaccine is being developed by University of Minnesota microbiologist Patrick Cleary and Wyeth. Human studies are expected to begin next year, he said.

New York-based SIGA Technologies, a developer of antibiotics and vaccines, is also working on a vaccine.

—

On the Net:

JAMA: http://jama.ama-assn.org

CDC: http://www.cdc.gov/ncidod/dbmd/diseaseinfo/#gas

AP-ES-08-10-04 1414EDT