A highly anticipated bird flu vaccine trial in Australia has proven protective for only a small minority of the 400 volunteers in the clinical trial.
Andrew Cuthbertson, the chief scientific officer of the vaccine manufacturer CSL Ltd., said about half who received the highest dose of the vaccine had an immune response comparable to that for regular human flu shots, reported the Sydney Morning Herald Friday.
Those in the trial who received single or smaller doses of the H5N1 bird flu antigen had a response below the threshold for licensing human flu vaccines. However, those receiving the vaccine had no adverse reactions beyond soreness at the injection site.
Cuthbertson said the comparison with ordinary human flu shots was "conservative" and if the deadly strain of bird flu H5N1 mutated to readily infect humans the required dose needed might be different.
CSL will begin a larger trial including children and the elderly who will receive a larger dose of the vaccine, according to Cuthbertson.
Copyright 2006 by United Press International
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