Richard Knox

A vaccine against human papillomavirus — the most common sexually transmitted infection and the cause of almost all cervical cancer — is dramatically reducing the prevalence of HPV in teenage girls.

The first vaccine against HPV, Merck's Gardasil, was approved by the Food and Drug Administration in 2006. Cerverix, from GlaxoSmithKline, was approved in 2009.

A once-a-day pill has been proven to lower the risk of getting HIV among needle-using drug addicts, just as it does among heterosexual couples and men who have sex with men.

Among 2,400 injecting drug users in Bangkok, those assigned to take a daily dose of an antiviral drug Viread, or tenofovir generically, had half the risk of getting HIV over a four-year period as those who took a placebo pill. Among those who took tenofovir faithfully, there were 74 percent fewer infections.

The World Health Organization is warning health care workers everywhere to suspect a disease called Middle Eastern Respiratory Syndrome, or MERS, whenever they see a case of unexplained pneumonia.

Monday's warning comes at the end of a six-day WHO investigation in Saudi Arabia, where 40 of the 55 cases of the respiratory disease have occurred. Sixty percent of those people with known infections died.

The chief of the National Institutes of Health is disavowing a ruling from the government office that oversees the ethics of human research.

Every day in hospitals all over America, thousands of patients die of infections that used to be curable. But the antibiotics used to treat them aren't working anymore.

It's called drug resistance, and it's largely a consequence of antibiotics overuse. The more germs are exposed to antibiotics, the faster they mutate to evade being vanquished.