Today, some four years later, Dr. Emini will show how well he's doing. The data he will present confirm unofficial information that healthy lab monkeys given the Merck vaccine stayed healthy after a subsequent injection of an AIDS-like virus. These results, first discussed at a closed-door research meeting in January and later reported by The Wall Street Journal, suggest that Merck is furthest along among several relatively new test vaccines intended to protect people against the lethal disease. We now need to see if the vaccine can generate a similar immune reaction in humans. The Merck vaccine, made from bits of the AIDS virus stitched into a deactivated common-cold virus, and several others like it face significant hurdles.
None seem likely to provide full protection against a viral attack.
Instead, if the vaccines work in people as they do in monkeys, they will trigger an immune-system reaction that may simply keep the virus that has invaded the body under control, unable to cause illness or death. Such a partially protective vaccine, while likely to keep an infected person alive for many years without the need for drug therapy, will still pose all sorts of potential concerns that may limit its widespread usefulness or acceptance. Merck's vaccine also faces at least three years of safety trials before it can be put into a large-scale test of its effectiveness. An efficacy study might take another three to five years to complete. We're going to do the experiments and wait and see.