Outbreaks of pertussis, known as whooping cough, are on the rise in North Carolina and across the U.S., and the reason is one that scientists never expected.
An updated version of the vaccine introduced in the 1990s to address adverse reactions is too weak to offer long-lasting immunity, experts say. For infants too young to be vaccinated, contracting whooping cough can be fatal. To combat the increase, schools nationwide are requiring students to have a pertussis booster prior to entering middle school.
Whooping cough, a highly contagious bacterial infection that affects the upper respiratory system, is spread through coughing or sneezing. The name comes from the whooping sound that occurs as air is forcefully sucked into the lungs between periods of violent coughing. (See video link in box.)
After a vaccine was developed in the 1920s, the number of reported cases each year dropped from the hundreds of thousands to just a few thousand in the 1980s. But this year, reported cases are already nearing 12,000.
Fourteen cases of whooping cough have been reported in Mecklenburg County this year. There have been 270 cases reported statewide.
Several factors, like better diagnostics and reporting, are contributing to the higher number. But the driving factor is waning immunity, said Stacey Martin, an epidemiologist for the Centers for Disease Control and Prevention.
While the vaccine offers very good short-term protection, we are seeing a decline in protection over time, Martin said. Were at least a decade out from any new vaccines. That means we need to use the current vaccines the best we can.
The first widely used pertussis vaccine, known at DTP, was made from whole pertussis bacterial cells. While this vaccine was successful in reducing the incidence of pertussis, it was known to cause irritation at the injection site, fever and, in some cases, uncontrolled spasms or convulsions.
The introduction of a new vaccine in the 1990s reduced adverse reactions, but it also cut the length of immunity.
Estimates for 2012 topped 40,000 cases of pertussis nationwide, a high that hadnt been seen since the mid-1950s. While the highest percentage of infections occurred in the 11- to 19-year-old age group, infants are most likely to die from pertussis.
For that reason, focus has shifted to vaccinating mothers during each pregnancy so that antibodies might be transferred to babies until they are old enough to receive the vaccine.
The early signs of pertussis a runny nose, sneezing, mild fever and occasional cough are similar to a common cold and might be overlooked by parents. But if the coughing fits become severe enough, infants may vomit, whoop as they gasp for air or stop breathing altogether.
In adolescents and adults, symptoms are generally milder, often not progressing beyond those of a cold, and the classic whoop isnt usually present, doctors say.
The cases that were seeing are in the elementary school age, said Julie Henry, spokesperson for the N.C. Department of Health and Human Services. And its not just children who need a pertussis booster, Henry said. Anyone who is going to be around a newborn baby needs to be vaccinated. (See box for info on adults.)
No one told me
Felicia Dube, 38, of Lancaster, S.C., wishes she had heard that advice three years ago before she delivered her son Carter. Nearly 10 years had passed since Dubes first son was born, and she and her husband were excited.
I re-read all the mommy books. I took my flu shot. I did everything they suggested to keep myself healthy and to keep the baby healthy, she said. But those books didnt mention the adult pertussis booster, she added.
A few days after Carters 5-week check-up, he became fussy. Even though it felt like they were overreacting, Dube and her husband, Daryl, called Carters pediatrician. That same day he was admitted to Levine Childrens Hospital, where he was treated for whooping cough even though doctors werent yet sure that he had pertussis. Less than two weeks later, the infant died.
We found out the next day that he had whooping cough. The test finally came back, Dube said. It was my job to protect him, and I didnt protect him. No one told me that I needed that booster.
Although Dube blames herself, theres no way to know where Carter picked up the infection.
Two years ago, the Dubes welcomed a baby girl, Brennan, to the family, and this time they didnt take any chances.
We didnt give anyone an option with Brennan. Have the shot, or you dont see the baby, Dube said.
And experts recommend just that.
Its important to emphasize that this can be really dangerous in infants, said Dr. Melissa Taylor, a pediatrician with Novant Health Randolph Pediatrics. Its important to vaccinate everyone around an infant the cocoon strategy if everyone is vaccinated, the infant is much less likely to catch the illness.
Dube is now speaks for Sounds of Pertussis, a public service campaign started by the March of Dimes and Sanofi Pasteur, the vaccine division of a French pharmaceutical company.
I feel like I have made a difference, even if it is just one person, Dube said. In the end, thats what its all about, protecting the ones who cant speak up to protect themselves.
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