After three AIDS vaccine trial failures, experts will gather in Maryland on March 25 to take stock of whatever has happened and decide on future strategies.

Last fall it was reported that some volunteers for a three-shot regimen by Merck might have left some volunteers more susceptible to HIV infection than before.

Scientists were badly shaken, and 15 vaccine researchers wrote to Dr. Tony Fauci, chief of the National Institute of Allergy and Infectious Diseases asking for a reassessment.

'When the STEP trial failed, it caused all of us to drop back a few yards,' said Fauci in a telephone interview.

Before the STEP two other trials had also collapsed, it may be noted here.

Also addressing the 15th annual Conference on Retroviruses and Opportunistic Infections in Boston, Ronald Desrosiers, director of the New England Regional Primate Research Center, said that the National Institutes of Health had 'lost its way,' and that current vaccine research trials were essentially futile.

'There is no rational basis for believing that any of the products in the pipeline have any reasonable hope of being effective,' said Desrosiers, a leading expert in vaccine studies using primates such as rhesus monkeys.

The only value of current or planned human vaccine trials, he noted sardonically, would be to prove that the products don't work.

'I would have used a different choice of words,' said Fauci, who does not believe his agency has 'lost its way.' However, he said, there was widespread consensus in the scientific community that more needed to be known about what biological steps were needed to cause the human immune system to ward off the virus.