Whooping cough vaccine: Why every child needs it
Whooping cough is caused by a bacterium called Bordetella pertussis. It's a bug that strikes only humans, so all the cases result from person-to-person transmission, usually by coughing. If the victim is a young child who has not been immunized, the disease is very serious. It starts innocently, almost like a common cold. After a week or two, though, things get dicey. Violent fits of coughing are punctuated by a characteristic whoop as the child struggles to take in air. The spasms often cause vomiting and typically produce dehydration, weight loss, and profound weakness. Without treatment, the whooping stage lasts two to four weeks and may end with a fatal pneumonia. Children who are treated with antibiotics and avoid that complication gradually recover, but it's a slow process that may take one to three months.
In adults and adolescents, the disease is much subtler and much less serious. As in kids, it often starts with a runny nose and a low-grade fever. Then the cough starts — and typically continues for two to four weeks. Most often, the cough is dry, and fever is mild or absent. Adults don't whoop or vomit and they don't get pneumonia. But the cough interferes with daily activities and sleep, and it may be violent enough to crack a rib. Most patients recover fully, but they often pass the infection to others in the meantime.
Until the mid-1940s, whooping cough was a major killer of American children. But routine infant vaccinations broke its hold. By 1976, only 1,010 cases were reported in the United States. Since then, however, the disease has staged a distressing comeback: Nearly 8,300 cases were reported to the Centers for Disease Control and Prevention in 2002, and countless others escaped diagnosis. Fortunately, the disease is rarely lethal in America, partly because it has shifted away from children. At present, 50% of cases occur in adults and teenagers. Still, 17 American babies died of whooping cough in 2002; none had been fully immunized. And without routine immunization, the disease remains rampant in the developing world, where it accounts for 300,000 deaths a year.
As with so many infections, the credit for the dramatic decline in whooping cough between 1945 and 1980 goes to a vaccine. In this case it's the P in the diphtheria, tetanus, and pertussis (DTP) vaccine that's recommended for every child.
The vaccine is the solution, but it's also part of the problem. The vaccine's protection is temporary; it begins to decline 5–6 years after the last booster. Waning immunity helps explain why adolescents and adults are coming down with whooping cough. But people cause another problem. Fueled by more than 100 anti-immunization Web sites, more and more parents are declining immunization.
Parental concern is understandable, and in this case it's a response to real problems. The original cellular vaccine often caused pain and swelling at the injection site. Fever, vomiting, and irritability were much less common, and seizures were rare, but these reactions got all the publicity and gave parents plenty of reason for concern. The concern persists, but it's no longer warranted. A new acellular vaccine has replaced the original preparation; it is at least as effective and is much, much easier on the patient.
As it now stands, the DTaP vaccine (diphtheria, tetanus, acellular pertussis) is recommended for all infants and children, but if parents don't allow their children to be vaccinated, the children will be at risk and be able to spread the infection to adults. Needless to say, the kids will also be inviting targets for diphtheria and tetanus, both life-threatening illnesses that are virtually 100% preventable.
April 2003 Update