Maryn McKenna

The chicken for sale at your local grocery store isn't like the chicken your grandparents used to eat. They're bigger and more "breasty," says public health journalist Maryn McKenna — and that's by design.

Superbug, a new book by journalist Maryn McKenna, tracks the spread of MRSA, the drug-resistant staph infection that seems to outwit every antibiotic thrown at it. McKenna explains how the bacteria has changed over the past 30 years -- and how a vaccine may be the only way to stop it.