Whooping cough, a bacterial infection also known as pertussis, is sweeping through California, with 3,400 cases reported. The condition is preventable by vaccines for infants and children, and by boosters for pre-teens, teens and adults whose immunity may have faded.

For infants and children, the immunization comes in the form of a combination vaccine that also protects against diphtheria and tetanus. Since 2005, the booster vaccine also has protected recipients from all three. Pregnant women can protect themselves and convey some immunity to their children by getting vaccinations during their third trimester, according to the Centers for Disease Control and Prevention.