The first vaccine against group A strep to be tested on people in 30 years appears safe and protective against the bacteria that causes strep throat, rheumatic fever and other illnesses.
But scientists reporting in today's Journal of the American Medical Association caution the results of a small clinical study are preliminary and a usable vaccine is years away.
The need for such a vaccine is greatest in developing countries, where rheumatic heart disease, a complication of strep A infection, is common, says lead researcher Karen Kotloff of the University of Maryland, informs Tucsoncitizen.com
According to Reuters.com safety concerns regarding potential cross-reaction with human tissues mean that years of study remain before a group A streptococcal (GAS) vaccine can be approved for public use, an expert asserts in an accompanying editorial.
"It has been about 30 years since a streptococcal vaccine even went into clinical trial," lead researcher Dr. Karen L. Kotloff told Reuters Health.
All GAS vaccines have been based on the M protein found on the surface of the bug, but antibodies produced against this antigen can also target human tissues -- which is why rheumatic heart disease can be a long-term consequences of group A strep infection.
Since the 1950s, vaccine research has focused on a protein on the bacterium - called M protein - that appears to help people develop immunity to infections. But organ cells have antigens on their surfaces which are similar to some parts of the M protein, so when the body attacks the bacteria, it also targets its own organs - such as the heart, kidney, or brain.
That autoimmune response seems to have been responsible for the rheumatic fever seen in the previous vaccine trial three decades ago, informs Newscientist.com
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