Scientists say further analysis of tests on an experimental AIDS vaccine offer disappointment and cause for optimism.
The latest results confirm that it is only marginally effective and suggest that its protection against HIV infection may wane over time. But scientists say one exciting part is that the vaccine does seem to have some effect, the first time that's happened. Scientists also think blood samples from the trial may show how to make a vaccine that does a better job.
The results also hint that the vaccine may work better in the general population than in those at higher risk of infection.
The test was done using thousands of HIV-negative men and women in Thailand ages 18 to 30 at average risk of becoming infected.
The results were published online Tuesday by the New England Journal of Medicine.