Science: Vaccines/AIDS/Mars Pathfinder

Theoretically ...

We had hoped for a vaccine effective against several diseases - and reported as much here on 5 August, about the trials by Stanford Rook of a TB vaccine. But the results are out, and the Phase III clinical trial in South Africa was a failure: SRL 172 showed no improvement on DOTS, the standard drug treatment (though as that is 95 per cent effective, maybe that's not surprising). Ever hopeful, Stanford Rook is waiting for the results from a Phase III trial against malignant melanoma (skin cancer). Present best treatments only manage 15 per cent success.

Confusion in the search for genetic resistance to AIDS: Earlier this year a team at the National Cancer Institute reported that a mutation in the CCR2 gene could slow down AIDS in HIV-positive people by two to four years. But a team at the Walter Reed Army Institute of Research in Rockville, Maryland, examined 400 people and found no difference. However, the NCI team reckons the new team couldn't find the effect because they didn't pinpoint the time of HIV infection.

Mars Pathfinder is finally talking to its owners. Recently the team at the Jet Propulsion Laboratory in Pasadena got their first signal after nine days in which the system fell into a mistiming problem. As the sun rose, several instruments turned on simultaneously before the solar panels were fully powered. The resulting drain caused a power dip, and so shut down the computer. That, in turn, threw off the computer's clock. And so it went on. Meanwhile the Sojourner rover drove itself in a slow circle around the lander, using a built-in program. Still, both have far outlived their primary missions - seven days for the rover and 30 for the lander. They're now pushing 90 days.