What is whooping cough?

Short Answer

Whooping cough, which is also called pertussis, is a very serious bacterial infection that affects the lungs and breathing tubes. The bacteria can become airborne when an infected person coughs or sneezes, infecting others who inhale the germs afterwards. Whooping cough starts with symptoms that are similar to a cold – a runny nose, mild coughing – then turns into violent coughing that is nearly impossible to stop once it starts. The name comes from the “whooping” sound children make when gasping for breath after a coughing fit. The disease is most harmful for young babies and can be deadly. The whooping cough vaccine, delivered as part of the DTaP combination vaccine (which also protects against tetanus and diphtheria), is 80-90% effective in preventing all three diseases.






Symptoms & Incubation

Symptoms of whooping cough usually appear seven to 10 days following infection, but can take up to three weeks in some cases.

Whooping cough starts with the following symptoms:

  • Runny or stuffed-up nose
  • Sneezing
  • Mild cough
  • A pause in breathing in infants (apnea)

After one to two weeks, coughing starts, which can be severe.

  • Children and babies can cough very hard, over and over.
  • When children gasp for breath after a coughing fit, they make a “whooping” sound. This sound is where the name “whooping cough” comes from. Babies may not make this sound.
  • Coughing fits make it hard to breathe, eat, drink, or sleep. Coughing fits happen more at night.
  • Babies and young children may turn blue while coughing from lack of oxygen.
  • Coughing fits can last for 10 weeks and sometimes recur with the next respiratory illness.



The disease is most dangerous for babies and young children. From 2004 through 2010, there were 148 deaths from whooping cough reported in the U.S. Almost all the deaths – 135 of the 148 – were babies 3 months and younger.

More than half of babies younger than 1 year who get the disease need care in the hospital. About one out of five babies and children with whooping cough will get pneumonia (a serious lung infection). Whooping cough can also cause seizures (jerking or staring) and brain damage.


Whooping cough spreads easily through the air when an infected person breathes, coughs, or sneezes. A person can spread the disease while he or she has cold-like symptoms and for at least two weeks after coughing starts.

Many babies and young children get whooping cough from adults or older brothers or sisters who don’t know they have the disease. Pregnant women with whooping cough can give it to their newborn babies. Because whooping cough is so harmful in babies, everyone around them needs to be vaccinated—to make a circle of protection.

High-risk Populations
Whooping cough is most harmful for young babies and can be deadly.


The DTaP vaccine is a shot that combines the vaccines for whooping cough (pertussis) and two other serious diseases: diphtheria and tetanus. Most children (about 89 children out of 100) who get all doses of the DTaP vaccine will be protected from whooping cough. But, protection from DTaP vaccine decreases over time. Some children who are vaccinated do get the disease, but it is usually a milder case.

A one-time booster vaccine for preteens and adults helps people stay protected against the disease.

Safety & Side Effects

The DTaP vaccine is very safe, and it is effective at preventing whooping cough (and two other diseases: diphtheria and tetanus). Vaccines are like medicines, and any medicine can have side effects. But severe side effects from the DTaP vaccine are very rare.

Mild side effects are seen in about one quarter of children and include fever, and redness, swelling, and/or tenderness at the injection site. These discomforts occur more often after the fourth and fifth doses of the DTaP series than after earlier doses.

Sometimes the fourth or fifth dose of DTaP vaccine is followed by swelling of the entire arm or leg in which the shot was given, for one to seven days (up to about one child in 30).

Other mild side effects include fussiness (up to about one child in three), tiredness or poor appetite (up to about one child in 10), and vomiting (up to about one child in 50). These problems generally occur one to three days after the shot.

More uncommon, moderate side effects include seizure (about one child out of 14,000) and high fever of 105 degrees Fahrenheit or higher (about one child out of 16,000).


Children should get five doses of the DTaP vaccine at the following ages for best protection:

  • One dose each at 2 months, 4 months, and 6 months;
  • A fourth dose at 15 through 18 months; and
  • A fifth dose at 4 through 6 years of age.

It is safe to get the DTaP vaccine at the same time as other vaccines, even for babies.

Preteens should get a whooping-cough booster vaccine (Tdap) at 11 or 12 years of age. Adults and teens that didn’t get the booster vaccine as preteens also should get it. This is very important for families and caregivers of babies.

According to the CDC’s Advisory Committee on Immunization Practices (ACIP), pregnant women should also receive a dose of Tdap during each pregnancy, even if they’ve gotten the vaccine during a prior, recent pregnancy. The ideal timing is between 27 and 36 weeks of gestation.

Since the Vaccine Was Introduced…

Before pertussis vaccines became widely available in the 1940s, about 200,000 children got sick with it each year in the U.S. and about 9,000 died as a result of the infection. Now there are about 10,000-25,000 cases reported each year and about 10-20 deaths.

Since the early 1980s, there has been an overall trend of an increase in reported pertussis cases. Pertussis is cyclic in nature, with peaks in disease every 3 to 5  years. But for the past 20 to 30 years, the peaks have been getting higher and overall case counts going up. There are several reasons that help explain why more cases are happening. These include increased awareness, improved diagnostic tests, better reporting, more circulation of the bacteria, and waning immunity.

Pertussis vaccines are effective, but not perfect. They typically offer high levels of protection within the first two years of getting vaccinated, but then protection decreases over time. This is known as waning immunity. Similarly, natural infection may also only protect you for a few years.

In general, DTaP vaccines are 80-90% effective. Among kids who get all five doses of DTaP on schedule, effectiveness is very high within the year following the fifth dose – at least nine out of 10 kids are fully protected. There is a modest decrease in effectiveness in each following year. About seven out of 10 kids are fully protected 5 years after getting their last dose of DTaP and the other three out of 10 kids are partially protected – protecting against serious disease.

The current estimate is that Tdap vaccination protects seven out of 10 people who receive it. Since Tdap vaccines were only licensed in 2005, we don’t yet have results on long-term vaccine protection. We’re still working to understand how that protection declines over time or might differ based on which vaccine was received during early childhood (i.e., DTaP or DTP). CDC will be conducting an evaluation in collaboration with health departments in Washington and California to better understand how long Tdap vaccines protect from pertussis. The data from these evaluations will help guide discussions on how best to use vaccines to control pertussis.

For current statistics on whooping cough in Vermont, visit healthvermont.gov/prevent/pertussis/surveillance.aspx.