The whooping cough epidemic continues to surge in California, and it has claimed the life of a third baby, state Department of Public Health officials said Friday.

The details

In just the past two weeks, 1,100 new cases of the disease, also known as pertussis, were reported to the health department. That brings the total number of cases so far this year to more than 4,500.

State officials said the third baby who died was a Sacramento child who contracted whooping cough last year at three weeks of age and was hospitalized for over a year.

Two other infants --  one in Riverside County and one in Placer County -- who like the Sacramento baby contracted the disease when they were too young to be vaccinated -- have also died this year of whooping cough.

Children can get their first dose of the DTaP vaccine, which protects against diptheria, tetanus, and pertussis, at around six to eight weeks. They are not considered fully protected until they've received at least three of the five recommended doses - usually by the time they are six months old.

A question arises

Following on the heels of the state's recent measles epidemic – which spread quickly among unvaccinated people - a question arises:

Are people who choose not to vaccinate their children contributing to the current whooping cough epidemic?

State health officials fielded that question several times Friday morning during a conference call with reporters.

State epidemiologist Gil Chavez said there are three primary reasons for statewide whooping cough epidemics:

1. Whooping cough epidemics are cyclical, occurring every three to five years.
2. The efficacy of the pertussis vaccine wanes over time. "Even if we do a fabulous job of vaccinating 100 percent of the population, after two to three years, that immunity wanes and people become susceptible to infection," said Chavez.
3. Contracting whooping cough does not provide lifelong immunity.

The bottom line, said Chavez, is that the existence of unvaccinated kids is "not so much a driver of what's happening with the epidemic statewide."

When people choose not to vaccinate their children against whooping cough,"it contributes more to outbreaks in communities where we have high rates of unvaccinated children, such as specific school settings," Chavez said, adding that that has happened at elementary, middle and high schools across the state.

The counties with the highest rates of whooping cough are Sonoma, Napa and Marin, according to state data.

The bottom, bottom line

In the end, Chavez said vaccination is still the best form of protection against whooping cough.

Infants too young to be vaccinated are must vulnerable to severe cases of the disease. Children four months old or younger have accounted for nearly two-thirds of the 142 pertussis hospitalizations this year, according to the state.

As a result, state health officials are recommending that pregnant women in their third trimester get vaccinated against the disease, as Impatient reported last week.

This way, mothers pass their antibodies on to their newborns, protecting them until they are old enough to get started on their series of vaccinations.

State officials also recommend that people who are around newborns get vaccinated, and that parents vaccinate their children.

But what's the point?

Dr. James Cherry, a pediatric infectious disease expert at UCLA, stressed that even though the vaccine's effectiveness wanes over time, "it's still better than no vaccine."

"Those who don't get vaccinated get sicker when they get pertussis," he said.

Have you or someone you know contracted whooping cough this year? Tell us about it in the comments section below, or e-mail us at Impatient@scpr.org. Your experience could inform future reporting.