Pertussis Frequently Asked Questions

A: Yes. Pertussis, or whooping cough, can be prevented with vaccines. Before pertussis vaccines became widely available in the 1940s, about 200,000 children got sick with it each year in the US and about 9,000 died as a result of the infection. Now we see about 10,000-25,000 cases reported each year and unfortunately about 10-20 deaths.

Pertussis vaccines are recommended for people of all ages. Infants and children should get 5 doses of DTaP for maximum protection. A dose is given at 2, 4 and 6 months, at 15 through 18 months, and again at 4 through 6 years. A booster dose of Tdap is given to preteens at 11 or 12 years of age.

Any adolescents or adults who didn't get Tdap as a preteen should get one dose. Getting Tdap is especially important for pregnant women and others who care for infants. You can get the Tdap booster dose no matter when you got your last regular tetanus booster shot (Td). Also, you need to get Tdap even if you were vaccinated as a child or have been sick with pertussis in the past.

Learn more about preventing pertussis.

A: Infants are at greatest risk for getting pertussis and then having severe complications from it, including death. More than half of infants younger than 1 year old who get pertussis are hospitalized, and 1 or 2 in 100 hospitalized infants die.

There are two strategies to protect infants until they're old enough to receive vaccines and build their immunity against this disease.

First, vaccinate pregnant women with Tdap during their third or late second trimester. By getting Tdap during pregnancy, mothers build antibodies that are transferred to the newborn, likely providing protection against pertussis in early life, before the baby can start getting DTaP vaccines at 2 months old. Tdap also protects mothers during delivery, making them less likely to transmit pertussis to their infants.

Second, make sure everyone around the infant is immunized. This includes parents, siblings, grandparents (including those 65 years and older), other family members, babysitters, etc. They should get the age-appropriate vaccine (DTaP or Tdap) at least two weeks before coming into close contact with the infant.

These two strategies should reduce infection in infants, since health data have shown that, when the source of pertussis could be identified, mothers were responsible for 30-40% of infant infections and all household members were responsible for about 80% of infections.

It's also critical that healthcare professionals are up to date with a Tdap booster dose, especially those who care for infants.

Learn more about infant complications.

A: Getting sick with pertussis or getting pertussis vaccines doesn't provide lifelong protection, which means you can still get pertussis and pass it onto infants.

Pertussis vaccines are effective, but not perfect. They typically offer high levels of protection within the first 2 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 5 doses of DTaP on schedule, effectiveness is very high within the year following the 5th dose – at least 9 out of 10 kids are fully protected. There is a modest decrease in effectiveness in each following year. About 7 out of 10 kids are fully protected 5 years after getting their last dose of DTaP and the other 3 out of 10 kids are partially protected – protecting against serious disease.

Our current estimate is that Tdap vaccination protects 7 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.

Keeping up to date with recommended pertussis vaccines is the best way to protect you and your loved ones.

Learn more about protection from vaccines and infection.

A: If you've been vaccinated and get pertussis, you are less likely to have a severe infection. Typically, your cough won't last as many days and coughing fits, whooping, and vomiting after coughing fits won't occur as often. When vaccinated children get pertussis, fewer have apnea (life-threatening pauses in breathing), cyanosis (blue/purplish skin coloration due to lack of oxygen), and vomiting.

Learn more about pertussis symptoms.

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

When it comes to waning immunity, it seems that the acellular pertussis vaccine (DTaP) we use now may not protect for as long as the whole cell vaccine (DTP) we used to use. Throughout the 1990s, the US switched from using DTP to using DTaP for infants and children. Whole cell vaccines are associated with higher rates of minor and transient side effects such as fever and pain and swelling at the injection side. Rare but serious neurologic adverse reactions including chronic neurological problems rarely occurred among children who had recently received whole cell vaccines. While studies have had inconsistent results that the vaccine could cause chronic neurological problems, public concern in the US and other countries led to a concerted effort to develop a vaccine with improved safety. Due to these concerns, along with the availability of a safe and effective acellular vaccine, the US switched to acellular vaccines.

Learn more about DTaP waning immunity [140 KB, 1 page] and pertussis outbreaks.

A: Even though children who haven't received DTaP vaccines are at least 8 times more likely to get pertussis than children who received all 5 recommended doses of DTaP, they are not the driving force behind the large scale outbreaks or epidemics. However, their parents are putting them at greater risk of getting a serious pertussis infection and then possibly spreading it to other family or community members.

We often see people blaming pertussis outbreaks on people coming to the US from other counties. This is not the case. Pertussis was never eliminated from the US like measles or polio, so there's always the chance for it to get into a community. Plus, every country vaccinates against pertussis.

Learn more about pertussis in other countries.

A: There are a lot of causes behind a person's cough and not every cough is pertussis. In general, pertussis starts off with cold-like symptoms and maybe a mild cough or fever. But after 1 to 2 weeks, severe coughing can begin. Unlike the common cold, pertussis can become a series of coughing fits that continues for weeks. The best way to know if you have pertussis is to see your doctor, who can make a diagnosis and prescribe antibiotics if needed.

The name "whooping cough" comes from the sound people make gasping for air after a pertussis coughing fit. However, not everyone with pertussis will cough and many who cough will not "whoop."

Teens and adults, especially those who haven't been vaccinated, may have a prolonged cough that keeps them up at night. Those who do get the coughing fits say it's the worst cough of their lives. And the cough may last for weeks or months, causing major disruptions to daily life and complications like broken ribs and ruptured blood vessels.

Infants may not cough at all. Instead, they may have life-threatening pauses in breathing or struggle to breathe. Any time someone is struggling to breathe, get them to a doctor right away.

Learn more about pertussis symptoms.

A: CDC is evaluating potential causes of increasing rates of pertussis, including changes in disease-causing bacteria types ("strains"). Unlike a foodborne illness where one strain causes an outbreak, multiple types or strains of pertussis bacteria can be found causing disease at any given time, including during outbreaks. There is a lot of diversity in strains causing pertussis in the US. While strains have changed over time, strain changes do not seem to be the cause of the increase in pertussis we've been seeing. And there's no direct evidence that strain changes have reduced the effectiveness of the vaccines. It's more likely that waning immunity is the driving force behind the increase in cases.

Learn more about CDC's Pertussis and Diphtheria Laboratory.

A: Pertussis spreads easily from person to person through coughing and sneezing. A person with pertussis can infect up to 12 to 15 other people. That's why being up to date with pertussis vaccines and practicing good cough etiquette are so important.

Many infants who get pertussis are infected by older siblings, parents or caregivers who might not know they have the disease. If pertussis is circulating in the community, there's a chance that even a fully vaccinated person of any age can catch this very contagious disease. But if you've been vaccinated, your infection is usually less severe.

If you or your child develops a cold that includes a severe cough or a cough that lasts a long time, it may be pertussis. The best way to know is to contact your doctor.

Learn more about pertussis transmission.

A: Herd immunity, or community immunity, is a situation in which, through vaccination or prior illness, a sufficient proportion of a population is immune to an infectious disease, making its spread from person to person unlikely. Even individuals not vaccinated (such as newborns and those with chronic illnesses) are typically protected because the disease has little opportunity to spread within their community. Since pertussis spreads so easily and vaccine protection decreases over time, we can't rely on herd immunity to protect everyone.

Vaccines provide the best protection against pertussis. Adult vaccination is an important part of community protection. However, fewer than 10% of adults have gotten their Tdap booster dose, so we can't yet measure how well herd immunity could work for pertussis. So it's even more important that everyone get their recommended pertussis vaccines to protect themselves.

Learn more about vaccine coverage.