Richard Knox

Researchers trudging down the long and twisted path toward an AIDS vaccine are encouraged by new studies that show an experimental vaccine protects monkeys against infection with a virus that is very similar to HIV.

If a heart attack sends you to an American hospital, you'll probably go home after only two or three nights. That's faster than virtually anyplace else in the world.

But your chances of needing to go back into the hospital within the next month are also higher than they are for heart attack patients in 16 other countries. That's the finding from a Duke University-led study in this week's JAMA, the Journal of the American Medical Association.

2011 has been a momentous year in the 30-year-old AIDS pandemic.

The big breakthrough was the discovery that antiviral drugs can prevent someone who's infected with HIV from passing the virus to others. It's nearly 100 percent effective. That led President Obama to declare earlier this month that the U.S. will expand HIV treatment in hard-hit countries by 50 percent.

Debra Meyerson was hiking near Lake Tahoe 15 months ago when a stroke destroyed part of the left side of her brain, leaving her literally speechless. It happens to more than 150,000 Americans a year.

But now Meyerson is learning to talk again through an approach that trains the undamaged right side of her brain to "speak." Specifically, it's a region that controls singing.

For more than 100 years, it's been known that people who can't speak after injury to the speech centers on the left side of the brain can sing.

Harvard researchers say they've uncovered a big problem among the nation's 700,000 police officers: a serious lack of sleep.

In what's believed to be the first study of its kind, the researchers queried nearly 5,000 municipal and state police officers in the U.S. and Canada about their sleep habits and symptoms of possible sleep disorders. Then they assessed their on-duty performance for two years.

Forty percent had sleep disorders, and the vast majority of these were undiagnosed before.

Doubts have been growing about Yasmin, Yaz and their sister contraceptives for several years now. And those doubts reached full flower at a Food Drug Administration advisory panel on Thursday.

A federally convened panel of experts says most men with newly diagnosed prostate cancer should be offered the chance to put off treatment in favor of medical monitoring of their condition.

In fact, the panel went so far as to say doctors should stop calling most of these low-risk tumors cancer at all.

If all goes according to plan — the plan President Obama laid out on Thursday — the HIV pandemic may reach an important tipping point by the end of 2013.

"We believe that with 2 million more people in treatment, we will reach a point where the number of new infections is less than the number going into treatment," says Dr. Eric Goosby.

AIDS activists haven't always been happy with Barack Obama. But many of them were on this Worlds AIDS Day.

The president used the occasion to pledge a 50 percent increase in the number of HIV-infected people getting treatment through the President's Emergency Plan for AIDS Relief, or PEPFAR — from around 4 million now to 6 million by the end of 2013.

The United States is doing a pretty miserable job of treating people with HIV.

The latest numbers show that only 28 percent of the nation's 1.2 million HIV-infected people are getting effective treatment — that is, antiviral medications to keep the virus in check.