>> the kind of illness we think of as a thing of the past, but there's a big outbreak in washington state and it's putting lives at stake. here is dr. nancy snyderman.
>> with the birth of her daughter fast approaching, this woman ignored her cough, dismissing it as a cold, but at two weeks old, her daughter caroline began to show similar symptoms.
>> she turned blue and was coughing and choking.
>> it was whooping cough, passed to caroline from her mother. that is heard here in the march of dimes public service announcement.
>> caroline recovered. one of many in an alarming breakout.
>> 640 cases have been reported and confirmed as of march 31st. last year, we had 94.
>> and four of those children have died. northern california, oregon, and vermont are also experiencing similar outbreaks. for health officials, it's all about childhood vaccination and booster shots as an adult.
>> many people think once you have your booster shots, you don't need to be vaccinated again. you may get a diminished disease, but you can still transmit the infection and all its veer llts to other susceptible people.
>> bo brooke had been vaccinated as a child.
>> i had inadvertently given my newborn a potentially life threatening illness that was so easably for vepreventable by getting my booster shot.
>> the goal is to make sure at least 90% of the population is vaccinated. why is it important? as we good gin to save more and more lives, cancer patients, patients with chronic immune cases, are the people we have to protect. it's something a shared responsibility for all of us.
>> and an old ilnlsz we didn't think we would hear much about anymore. thank you.
