Pertussis Vaccine Offers Prevention Alternative

by Food and Drug Administration (FDA)

As school bells ring this fall, the country's 3.3 million first-graders will clutch new Ninja Turtle lunch boxes and brightly colored backpacks. But before they enter classrooms, many will receive something new at the doctor's office as well — a safer pertussis vaccination.

Approved by the Food and Drug Administration last December, the new vaccine for pertussis, or whooping cough, offers immunity with fewer side effects than the older version, which caused some concern among physicians and parents.

"I think most physicians would like to see all of the reactions eliminated completely," says Donald Schiff, M.D., a spokesman for the American Academy of Pediatrics and a pediatrician at Denver Children's Hospital.

Developed in Japan about 10 years ago, the new vaccine is distributed by Lederle Laboratories of Wayne, N.J.

The pertussis vaccine is given in combination with diphtheria and tetanus vaccines in a series of five DTP shots between 2 months and 6 years of age.

The new vaccine is approved for the last two doses of the series. Children getting it must be at least 15 months old because it has not yet been tested adequately in younger children.

It is younger children, however, who most often react severely to the old vaccine.

"The new vaccine does not relieve those who are most anxious about it — the parents of infants," says Schiff.

Fewer Side Effects

In about half of all children, especially infants, the traditional pertussis vaccine causes some uncomfortable side effects, such as swelling and soreness at the site of the shot, fever, and inconsolable crying several hours later.

For a very few others, however, the side effects are much worse. They include shock, convulsions and seizures. The vaccine has even been blamed for some cases of brain damage, but this association has not been proven.

The new vaccine has fewer common side effects. The incidence of severe side effects is still not known, however, since they occur so rarely. Hundreds of thousands of children will have to be vaccinated before doctors can document these.

In theory, the new vaccine should be much safer. Instead of being made like the old vaccine from whole pertussis bacterial cells that have been killed, the new acellular vaccine is made only from parts of pertussis bacteria that evoke protective immune responses.

Although the new acellular vaccine is available, not all eligible children need it. Many children tolerate the whole-cell vaccine just fine, and it is less expensive than the new one. Parents should check with their children's doctor about which vaccine is right for them.

In any case, children younger than 15 months should still be given the old vaccine unless their doctors recommend otherwise.

"It's important to realize that while there is a new vaccine, the old vaccine is very good, too," says Drusilla Burns, Ph.D., a research chemist in FDA's Laboratory of Pertussis who is involved in pertussis research and helped review the new vaccine.

"The whole-cell vaccine has served us very well," she adds. "It has some relatively minor adverse reactions, but the more severe reactions are still a matter of discussion."

The American Academy of Pediatrics and pediatric societies in Canada and Great Britain have stated that the vaccine is not a proven cause of brain damage.

And, while the risk of seizures from the whole-cell vaccine is about 1 in 1,750, numerous studies have shown there's no evidence those seizures will permanently harm the child or increase his or her chance of developing other seizure disorders, such as epilepsy, later.

For most children, the benefits of the whole-cell pertussis vaccine far outweigh its risks.

Deadly Disease

Whooping cough is highly contagious and deadly. It causes mucus to build up in the lungs, making the child gasp and "whoop" for air every few minutes for two to three weeks.

The spasms may bring on vomiting, pneumonia, and sometimes brain hemorrhages. Spreading through droplets of moisture expelled by coughing, whooping cough bacteria will infect up to 90 percent of unvaccinated people exposed, especially young children. Both the old and new vaccines protect about 80 percent of children exposed to the disease, and the remainder have mostly mild cases.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.