H5N1 vaccine not very effective

The H5N1 vaccine showed only modest results in its trial phase.

3 April March 2006

BY A CORRESPONDENT

Its bad news from the H5N1 vaccine testing labs. The H5N1 vaccine showed only limited benefits during its first trial phase. The avian influenza trial yielded only modest results with the vaccine generating a sufficient immune response in slightly more than half of those who were given heavy doses.

The New England Journal of Medicine states that, out of the volunteers who were given twice the standard dose of the drug, 54% produced a medical report that is supposed to be protective. The rest of the volunteers, who were given the usual doses were less likely to show an adequate immune response.

The seasonal flu vaccine didn't cause any serious side effects, even with the volunteers who were given high doses. Although there were a few significant side effects, 84% of them were classified as mild considering the fact that there were no serious allergic reactions. The H5N1 vaccine trial was funded by the National Institute of Allergy and Infectious Diseases(NIAID). 

The influenza trial was done last year and the tested vaccine is based on an H5N1 virus taken from a Vietnamese patient in 2004. The H5N1 vaccine which was used for the trial was produced by Sanofi Pasteur, but it was not a part of the study.

The researchers expect two 90-mcg doses of the H5 influenza vaccine would have a sufficient tolerability profile and it could prevent the Avian influenza in healthy adults. The vaccines for elderly people and children are in progress. 

Though the limitations of the vaccine have been revealed in the study, researchers see it as progress. Further research is expected to increase the acceptability of the H5 vaccine much more.