Microsoft Corp. chairman Bill Gates pledged $250 million for a total of $450 million to a project he initiated in 2003 to get the world's top scientific minds to find remedies of the deadliest diseases.

He announced the contribution while delivering a speech as a featured speaker at the World Health Organization's annual assembly on Monday.

Medicare covers 43 million elderly and disabled Americans.

The White House projects the total cost of covering prescription drugs over the next decade at $724 billion, of which $2 billion will be used for impotency drugs.

Swiss researchers reported results Saturday of an experimental vaccine against nicotine that helped smokers kick the habit.

Still in its preliminary stages, the test of heavy smokers suggested that 40 percent were able to quit smoking for nearly six months after receiving the vaccine.

According to a recent report on the situation in Angola, the death toll from the Marburg virus outbreak is now 292, out of the 336 known cases.

WHO spokesperson Aphaluck Bhatiasevi, in a phone interview with Reuters said, "We've seen new cases in new municipalities that don't have obvious links to earlier cases of Marburg. We are very concerned about the situation."

A recent study showed that nearly half of those patients who took the experimental drug Revlimid, showed little signs of the gene mutation which causes the disease. In other cases, the abnormality was completely eradicated.

Specialists are now saying the drug looks like the first effective treatment for people with the cancer.