(CBS) As California's whooping cough epidemic claims its tenth victim, a six-week-old baby in San Diego, health officials in the state are scrambling to educate people about the importance of vaccination.
Whooping cough, a.k.a. pertussis, is highly contagious, but infants under the age of two months cannot be vaccinated, says CBS News medical correspondent Dr. Jennifer Ashton. That's why it's imperative for adults who live and work around kids to get vaccinated - and to keep their vaccinations up to date.
"The fatalities in California and the babies exposed in California - in more than 50 percent of cases - they were exposed to whooping cough by a family member," Dr. Gil Chaves of the California Department of Health told CBS News.
Only six percent of adults are properly vaccinated against whooping cough. The vaccine needs a do-over about every five years.
More than 5,270 people have been infected in California, but whooping cough is a concern nationwide. The bacteria that cause the infection spread through the air when people cough or sneeze.
"If you've ever heard that barky type of cough, you know what it sounds like. You will not forget it," Ashton says. But she points out that some cases of pertussis don't produce the characteristic cough.
In adults and children, the infection starts out like the common cold with mild coughing and runny nose. It typically takes a week or two before the violent cough appears.
"If you or I get sick," Aston said on the Early Show, "not a big deal. If we pass it on to a newborn, it could be deadly."