Shots - Health News Shots - Health News Health News From NPR

Low water levels, like at this reservoir near Gustine, Calif., bring birds and mosquitoes together and help transmit West Nile virus to humans. Rich Pedroncelli/AP hide caption

itoggle caption Rich Pedroncelli/AP

No amount of training can undo the violence someone experienced at home as a child, but it can help break the cycle. Pamela Albin Moore/iStockphoto hide caption

itoggle caption Pamela Albin Moore/iStockphoto

Psychologists say spanking and other forms of corporal punishment don't get children to change their behavior for the better. Science Photo Library/Corbis hide caption

itoggle caption Science Photo Library/Corbis

San Francisco Supervisor Scott Wiener (left) says he started taking a drug to prevent HIV infection earlier this year. Lisa Aliferis/KQED hide caption

itoggle caption Lisa Aliferis/KQED

This human-scale lab rat cage is parked near a skate park in Denver, Colo., to make a point about the lack of science on marijuana. Richard Feldman Studio/Sukle Advertising and Design hide caption

itoggle caption Richard Feldman Studio/Sukle Advertising and Design

Dr. Harold Varmus, a Nobel Prize winner, cancer biologist and director of the National Cancer Institute. Manuel Balce Ceneta/AP hide caption

itoggle caption Manuel Balce Ceneta/AP