It started out much like any winter cold. But, soon enough, 16-year-old Zachary Graham couldn't stop coughing. And coughing.
When doctors finally diagnosed Zach a few weeks later, they told him that his hacking fits - which sometimes made it hard to breathe and sleep - were caused by a disease the teenager thought he couldn't get: whooping cough.
"When I was diagnosed, my parents and I were surprised that I had it because I had been vaccinated against the disease," said Graham, a high school junior from Sunapee, N.H., whose illness kept him off the ski slopes and away from his friends.
This week, an advisory panel to the Food and Drug Administration declared that two new whooping cough booster shots were safe and effective. The vaccines, manufacturers say, could stem rising rates of the illness - known medically as pertussis - in adolescents in the United States. A final decision by the FDA is pending.
"This is a great thing," said Dr. Daniel Levy, an Owings Mills pediatrician who is also a spokesman for the American Academy of Pediatrics. "Pertussis - whooping cough - is a huge problem in older children and adolescents, not to mention adults."
In June, a similar panel convened by the U.S. Centers for Disease Control and Prevention will discuss whether to recommend that the shots be added the regimen of immunizations already in place.
Pertussis vaccine is currently given to babies at 2, 4, 6 and 18 months, and finally to children just before kindergarten. But the vaccine's effectiveness wanes over time, making some teenagers and adults newly vulnerable. If the new vaccines are approved, they could boost a person's immunity at that point.
One of the new vaccines, by GlaxoSmithKline, is tailored for children 12 to 18. The other, by Aventis Pasteur, could be given to people 11 to 64.
Like the early-childhood vaccines, the new ones would be contained in a solution that also protects against tetanus and diphtheria.
Whooping cough, sometimes called the "100-day cough" because the symptoms can persist that long, is a highly contagious disease caused by bacteria that enter the mouth, nose and throat. The illness causes severe spasms of coughing that can interfere with eating, drinking and breathing.
It derives its familiar name from the disturbing "whoop" sound that children make as they struggle to inhale after a series of coughs. Severe fits can trigger vomiting, and some patients can even break a rib.
Adults usually have milder cases of pertussis than younger victims, who may ultimately wind up hospitalized with complications like pneumonia or seizures.
For public health specialists, whooping cough has been a resilient foe. Polio has been wiped out in this country, along with more than 99 percent of mumps, measles and diphtheria cases. But vaccination efforts have gotten rid of only 92 percent of whooping cough infections, and cases have been on the rise since the 1980s.
"We're not doing quite as good a job at preventing pertussis cases as we do other vaccine-preventable diseases," said Dr. Colin Marchant of the pediatrics department at the Boston University School of Medicine.
Last year, nearly 19,000 cases of pertussis were reported, according to the CDCP in Atlanta. That figure - up from 11,647 cases in 2003 and 8,296 in 2002 - was the highest in more than four decades.
Part of the increase might be due simply to rising awareness among physicians about the symptoms of whooping cough. The disease can be difficult to diagnose because it often mimics that common cold at first, and lab tests can't always pick it up.
But most experts agree that waning immunity among patients who were vaccinated as children is a large part of the story. Why the disease is rising now remains something of a mystery, though epidemiologists have noted that upsurges tend to run in three- to four-year cycles.
Much like polio or measles, pertussis was once a common childhood illness in the United States. It was also a leading cause of infant mortality in the United States. In the 1930s, there were typically more than 200,000 cases reported annually. Infections started dropping in the next decade with the introduction of a pertussis vaccine. By 1976, there were only about 1,000 cases a year, Marchant said.
Recent outbreaks have begun in hospitals and schools, at parties and summer camps. Four years ago, a school in Pike County, Ark., had to be shuttered after a third of its students became sick with whooping cough. The outbreak started among members of the football team.
Westchester County, which is just north of New York City, typically sees six to eight pertussis cases a year. But between July 2003 and last December, health officials recorded 151. What started in effect as a single infection made its way into 40 cities and towns.
"Eleven of the infected children had not been vaccinated against pertussis and did contribute in part to the onset of the outbreak," Dr. Joshua Lipsman, Westchester's health commissioner, said in a recent news briefing.
Since antibiotics are only marginally effective, depending on how soon they are given, experts say the best protection against whooping cough is vaccination.
"What we need to do is start immunizing the adolescents," said Marchant. "Your immune system just needs some boosting with another dose of vaccine."