A painting of Louis Pasteur in his laboratory. The French chemist and microbiologist once said, "Fortune favors the prepared mind." A new report on pandemics bears a similar message.
This year's flu vaccine protects against a few different virus strains, including the H1N1 seen here. The fuzzy outer layer is made of proteins that allow the virus to attach to human cells.
A blood test developed by Harvard researchers checks for evidence of past infection with more than a thousand strains of virus, from about 200 virus families. The swine flu virus shown here, A/CA/4/09, rarely infects humans.
C. S. Goldsmith/CDC