You may think whooping cough is something only children or babies get. But the famous childhood illness, also called pertussis, most often affects adults. And, although whooping cough is rarely deadly after childhood, teens or adults can pass the infection to a vulnerable unvaccinated infant.
The immunity granted by the childhood pertussis vaccine is effective, but short-lived. Immunity to pertussis wanes five to 10 years after the last childhood vaccine. Immunity after natural infection also wears off in several years. Revaccination with a booster shot renews immunity for teens and adults, preventing infection and the spread of whooping cough.
Why Whooping Cough Won’t Just Go Away
Until widespread vaccination against whooping cough was introduced in the 1950s, whooping cough killed thousands of children every year in the U.S. Today, with about 80% to 90% of Americans vaccinated, serious cases of whooping cough have declined dramatically. But the disease has never been eliminated completely.
How many new cases of whooping cough crop up each year is difficult to say: Estimates range from half a million to a few million. Most of these occur in teens and adults. Whooping cough appears to be on the rise, although this may be in part because of improved detection and reporting.
The number of infections is impossible to pin down because whooping cough in teens and adults is generally mild, thanks to early immunizations. People usually mistake whooping cough symptoms for a cold and never seek medical attention. Doctors even have a difficult time recognizing whooping cough in teens and adults, and commonly misdiagnose it as bronchitis, asthma, or the common cold.
Undiagnosed, "mild" whooping cough in teens and adults can still mean a cough that lasts for weeks, disturbing sleep and leading to days missed from school or work. And most seriously, unrecognized whooping cough circulates the whooping cough germ, which eventually infects vulnerable infants.
Tdap: The Whooping Cough Vaccine for Adults
In 2005, the FDA approved a booster vaccine for whooping cough. Called Tdap, the vaccine is given in a single injection and also protects against tetanus and diphtheria. Tdap provides about 90% immunity against whooping cough. Though it's unknown how long protection from the Tdap booster shot lasts, it seems to be at least five years.
The CDC recommends that all adolescents and adults from age 11 and up receive a single booster dose of Tdap. In adolescents, Tdap should replace the usual tetanus booster shot that’s due around the same time. In adults, Tdap can be given at any time, although it may be better to wait a few years if a tetanus booster was recently given.
Pregnant women are encouraged to get a Tdap vaccine, preferably between 27 and 36 weeks' gestation. This is because most whooping cough deaths occur in babies younger than 3 months old. It’s also recommended that every adult and teen in a new baby’s household should receive Tdap.