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    Mayo Clinic Q and A: Vaccine against pertussis effective, but immunity can weaken

sad or sick baby in pink blanket crying, coughing
How is it that children who have been vaccinated against pertussis still end up with the disease? Was the vaccination they received not effective? There are many new cases of it in our school, and adults are being told to get a booster. Is this just to protect children, or can adults get the disease as well?

ANSWER: The vaccine against pertussis, or whooping cough, is effective; however, the immunity the vaccine generates tends to weaken over time. To counter this, boosters of the pertussis vaccine are recommended for children as they get older. Adults can get pertussis, too. For the best protection again this infection, and to help keep it from spreading, adults who are regularly in close contact with young children should get a vaccine booster.

Pertussis is a highly contagious bacterial infection that causes a severe, hacking cough. The coughing spells can be followed by a high-pitched intake of breath that sounds like a “whoop” and gives the disease its name. Coughing spasms can cause extreme fatigue and vomiting. They also can make it hard to breathe. In babies, the disease is often serious because infants’ airways are small, and they may have trouble breathing in enough oxygen during these coughing spells. Severe coughing can also generate small hemorrhages in the eyes and brain.

Vaccination is the best way to prevent pertussis. Infants should be vaccinated at 2, 4 and 6 months of age. The pertussis vaccination is given in combination with tetanus and diphtheria vaccines. It’s abbreviated as DTaP for diphtheria, tetanus and pertussis. Boosters are recommended at 12 to 18 months, 4 to 6 years, and again at age 11. Pertussis booster shots are available for adults, too. They are strongly recommended for those in close contact with infants, particularly during a pertussis outbreak.

Pertussis vaccines are very safe, effective and beneficial. Before the vaccine was available, pertussis was a feared disease that killed thousands of children every year. Now, perhaps 10 to 20 pertussis deaths occur per year in the United States. Almost all of these deaths are in infants.

People of all ages can still get the disease. Since the 1980s, the number of pertussis cases has been increasing in the United States. Pertussis persists for several reasons. First, vaccinations aren’t universal. Not everyone who needs the vaccine gets it. Second, over time the vaccine’s effectiveness wanes, so adolescents and adults who don’t get a booster can develop pertussis.

Older patients typically have a milder form of the illness because they keep some immunity from their early vaccinations. Nonetheless, even those with mild pertussis are still contagious. The disease can be transmitted through germ-filled droplets propelled into the air from a cough or sneeze.

People who have pertussis are treated with a specific type of antibiotic. To prevent the illness from spreading, they need to stay home from school, day care or work until they have had five days of antibiotics. A doctor may recommend antibiotics for everyone in the household because pertussis is easily transmitted.

Antibiotics work best when given early in the course of the illness. Treatment doesn’t immediately stop the cough. Pertussis is sometimes called the 100-day cough because symptoms can linger that long.

Home care includes plenty of rest and fluids. Cough medications aren’t helpful and aren’t recommended. Infants who have pertussis may need to be monitored in a hospital to make sure they can breathe on their own after a coughing spell.

The best way to fight pertussis is to keep it from developing in the first place. All infants and children — as well as adult family members and caregivers — need to be fully vaccinated against pertussis. If you’re not sure whether you need a pertussis vaccine booster, ask your doctor to check your vaccination record and make sure it is current. Thomas Boyce, M.D., Pediatric Infectious Diseases, Mayo Clinic, Rochester, Minn.

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