Flu vaccine is made in eggs, but that’s too slow for a major epidemic. How are vaccines made inside animal cells? What other methods can protect us against a fast-changing, deadly virus?

Virologists have been working late since swine flu appeared in April. With flu running amok in South America, what can we expect when the epidemic returns north this fall?

New study finds 2 percent of scientists admit faking data; 14 percent say colleagues have done it. Problems are most common in drug and other medical studies.

The epidemic fades, with 61 confirmed deaths and 5,251 cases so far. Were the public health warnings overdone? Or did they help stem the pandemic? Your guide to the time of finger-pointing, flu-style.

New video captures AIDS moving inside immune cells: HIV enters pods that form on the surface, then jumps across into a healthy immune cell that is now doomed to spread HIV — and die.

The discovery of human embryonic stem cells seemed to offer cures for horrific diseases. After 10 years of research, was that hype? Where are the cures from stem cells?

After decades of effort, gene replacement brings eyesight to the blind. How did it work? What does animal research say about gene therapy for curing cancer, reducing pain or reversing muscular dystrophy? Why has gene therapy taken so long?

Financial traders make more money when their blood has more testosterone. Is this another arena where the male hormone leads to success, or could success raise the hormone level?

As pathogenic bacteria advance, scientists are desperately scrounging around for new ways to fight them. But would you believe healing clay, gator blood, honey and crushed leaves?

Before type 2 diabetes or heart disease comes “metabolic syndrome,” a devil’s-brew of high blood pressure, bad cholesterol, a big waist and insulin resistance. Want to stop the slide – without drugs?