a063  0552  03 Sep 88
PM-Strep Vaccine,0459
Scientists Test Strep Vaccine
By WOODY BAIRD
Associated Press Writer
    MEMPHIS, Tenn. (AP) - A vaccine that blocks strep throat and
rheumatic fever has been successful with laboratory animals and may
be ready for human tests in six months, a medical researcher says.
    The vaccine is made through genetic engineering, by attaching genes
from streptococcal bacteria to a form of salmonella bacteria rendered
harmless in the laboratory.
    Edwin Beachey, a microbiology professor at the University of
Tennessee-Memphis, says mice given the vaccine withstood doses of
strep that were thousands of times greater than needed to trigger an
infection.
    He said Friday he is applying to the federal government and the
required review boards at the university to test the vaccine on human
beings.
    ''It's a new approach to vaccination with an engineered organism and
so it has to pass some standards that many review boards are not
quite used to,'' said Beachey, who also is director of research at
the Veterans Administration Medical Center in Memphis.
    Results of work on the vaccine were published last month in the
Journal of Experimental Medicine.
    The research was conducted by Beachey and Thomas Poirier of the
Memphis medical school and Michael Kehoe of the University of
Newcastle in London.
    They attached a strep gene to a weakened form of salmonella bacteria
that causes typhoid fever.
    The salmonella, which has been used for years in a typhoid fever
vaccine, was induced by the strep gene to produce a substance called
M protein, Beachey said.
    Given to laboratory mice, the salmonella died quickly in the
animals' intestines while the M protein led to the production of
antibodies for rheumatic fever.
    The weakened salmonella, genetically altered in 1985 by other
researchers, has been given to thousands of people to prevent typhoid
fever, but this is the first time it has been used to transmit
genetic material from another form of bacteria, Beachey said.
    ''We're simply using it as a delivery vehicle where we can clone
another gene into it,'' he said. ''You sort of have a double barrel
here where you're not only vaccinating against typhoid but in the
same dose you're also vaccinating against strep sore throat and
rheumatic fever.''
    Rheumatic fever, which can cause fatal heart damage, is a major
health problem in Third World countries and incidents of the disease
appear to be on the increase in the United States, Beachey said.
    ''It had declined over the last 20 years but in the last three or
four years it has been rising up again. Here in Memphis we used to
see maybe one or two cases a year and last year we saw 35,'' he said.
    
 
AP-NY-09-03-88 0842EDT
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