Monday is World AIDS Day, a time to revaluate efforts to fight the pandemic, which has killed more than 20 million people in a little more than two decades. Health experts agree that the best way to stop the spread of the disease is by developing a vaccine. However, one is not expected any time soon.

Among those push for greater funding and research is Dr. Seth Berkley, head of the ?International AIDS Vaccine Initiative,? or IAVI. From New York, he spoke to English to Africa reporter Joe De Capua about current research. Dr. Berkley says, ?The exciting thing is that for the first time we now have more than a dozen products in trials around the world. So, first of all, there?s a lot more in the pipeline. And secondly, it is now really international. We?re beginning to see vaccines tested in Asia, all across Africa, obviously in the United States and Europe, and that?s all good for trying to move the field forward.?

But he says it takes a long time to develop a vaccine for a virus like HIV because it mutates and manages to hide from parts of the immune system.

As for funding, he says it has increased from about $125 million to about $550 million globally. Nevertheless, he calls that ?a drop in the bucket.? He says it would be better if funding reached one to two billion dollars per year.