Whooping Cough Outbreak: CDC Answers Your Questions

For a disease that many Americans believe disappeared long ago, the numbers are staggering.

More than 21,000 cases of whooping cough have been reported this year nationwide, claiming 13 lives — all babies. Washington state has declared an epidemic. And throughout much of the rest of the nation, the outbreaks have been worse than at any point in the last half-century.

After this week’s NewsHour series on the resurgence of the disease, you had questions — lots of them. As promised, we’ve had them answered by Dr. Tom Clark, a medical epidemiologist with the Centers for Disease Control and Prevention. Find his responses to 20 of them below.

But first, let’s brush up on the basics of pertussis, as the disease is formally known.

If you missed it, watch health correspondent Betty Ann Bowser’s full report investigating some of the reasons behind whooping cough’s rebound:

Our coverage continued online, where the Centers for Disease Control listed the “Top 10 Things You Need to Know About Whooping Cough.” We heard from parents on both ends of the vaccination debate, and we profiled a young woman who lost her baby to whooping cough just 27 days after giving birth.

We knew you would still have questions. So without further ado, here’s Dr. Tom Clark of the CDC with the answers.

1. Question from viewer “Julie Anderson1215”: My daughter, age 31, was not vaccinated as a child due to seizures as an infant. Her pediatric physician recommended that she not be vaccinated. She outgrew the seizure disorder. Her children have been vaccinated, but should she now get the vaccination?

Clark: Seizures within 48 hours of receiving whole cell pertussis vaccine (DTP) occurred in about 1 in 1,750 doses. During the 1990s, DTP vaccines were phased out and replaced with acellular vaccines (DTaP). Seizures following DTaP vaccines are reported much less frequently than after DTP. If your daughter has not yet gotten it, she can get a dose of Tdap. She should discuss with her doctor.

2. Question from viewer “PP”: Back in 1954, I had whooping cough. We didn’t know what it was until the last family member with it went to the doctor. Does having had pertussis provide lifelong immunity? Should I receive the booster?

Clark: Having had whooping cough in the past — or being vaccinated — does not provide lifelong immunity. All adults are recommended a booster shot, called Tdap. For more information, see question No. 3 in our Top 10 Things You Should Know About Whooping Cough.

3. Question from viewer Sheldon Klimist: I have a compromised immune system (cll) and I am 81. Should I get a booster shot for whooping cough?

Clark: Pertussis vaccines do not contain live bacteria, so they are safe to be given to people who have conditions that compromise your immune system. All adults are recommended a Tdap booster, and you can get it. So please ask your doctor about receiving the vaccine.

4. Question from viewer “A389”: So, if I understand this correctly, even if I received the DTP vax in the late 1940s, I should get a booster. Is that correct?

Clark: In adults who were vaccinated many years ago, protection has likely worn off substantially. All adults are recommended a Tdap booster.

Comment from viewer “McGary”: “The article seems to ignore the huge migrant population of the state. This group has a deficit in vaccination against disease. Until illegal individuals are identified and treated by vaccine, a huge and growing pool of individuals, carriers within families … are present among our population.” Is immigration a factor in the latest outbreak of whooping cough?

5. Clark: It is often suggested that pertussis outbreaks can be attributed to people “importing” the disease when they come to the U.S. from other countries, but this is not the case. Prior to vaccination, there were upwards of 200,000 cases and 9,000 deaths from pertussis every year in the U.S. alone. While we have greatly reduced the burden of pertussis through vaccination, it was never eliminated. It is always present in our communities. Further, reduction in the burden of vaccine-preventable diseases, including pertussis, is one of the great successes of public health. Every country vaccinates children against pertussis, and in the Americas, every country has achieved pertussis vaccine coverage of 78 percent or higher. While all people should be vaccinated on time according to the recommended schedule, under-vaccination is not the cause of the current outbreaks.

6. Question from NewsHour viewer Molly Moynihan: Are there any long term-side effects (particularly to voice and lung function)?

Clark: Pertussis itself can cause pneumonia, especially in infants. Sometimes this can be severe, requiring intensive care. Following such severe disease, people may recover gradually and may not recover completely. Lasting effects on lung function might result in shortness of breath or fatigue that limits activity. The potential for serious and lasting effects of pertussis are an important reason that children should begin their vaccines and receive every dose on time.

Pertussis vaccines are very safe. Local reactions at the site of the injection are common but are mostly mild and resolve on their own in a few days. Serious adverse events are rare. There is no association with lung or voice problems and vaccination. When health care providers give recommended vaccines, they provide a Vaccine Information Statement to help explain the types and frequency of adverse events. It’s always important to discuss specific concerns with your doctor before getting vaccinated or when you are sick.

7. Question from viewer Molly Moynihan: Why is vaccine coupled with tetanus — we’ve heard it is dangerous to have another tetanus shot too soon, so my husband could not get the booster.

Clark: Pertussis has traditionally been combined with tetanus and diphtheria vaccines because they have similar dosing and boosting schedules. There is no need to wait between getting your last Td (tetanus) booster and your Tdap shot. Local reactions at the site of the injection, like pain, redness or swelling may occur, but these are mostly mild and resolve on their own. There is no increased risk for serious adverse events.

8. Question from viewer “Vaccinateornot”: I’d like to see a stat. What percentage of people who get pertussis have had the vaccine, and what percent have not had the vaccine? The assumption in this article is that the unvaccinated population is spreading this disease, but no evidence is being given of that. A simple look at who is getting this disease would answer this question. I read a stat that said that if you get the vaccination, you are six times more likely to get the disease. Again, no citations or studies provided with that. We need some real stats on this to make an informed choice.

Clark: Pertussis vaccines are very effective, but they are not 100 percent effective. Vaccine protection wears off over time, so vaccinated people might still get pertussis. This is known as waning immunity. By five years, after their fifth dose of DTaP, 3 in 10 vaccinated children are susceptible again and can get pertussis. This is why the Tdap booster is recommended at age 11 or 12 years. Children who have not been vaccinated against whooping cough are at greater risk — at least 8 times more likely — to get pertussis than children who received all five doses of DTaP on schedule. Pertussis in an unvaccinated child can be severe at any age. More than 95 percent of U.S. children receive three or more doses of pertussis vaccines, while less than 1 percent are completely unvaccinated. Because of this, we usually find that most pertussis occurs among vaccinated people. This does not mean that the vaccine doesn’t work, it just means that most people are vaccinated but protection wears off.

For an example, see this MMWR publication.

9. Question from viewer “Tina”: With concerns about waning immunity, what is the current recommendation for timing of DTaP immunizations for adults?

Clark: The acronyms for pertussis vaccines can be confusing, but convey important information to health care providers. DTaP is for infants and children, while Tdap is for adolescents and adults. DTaP vaccines have been used for many years, but we have only used Tdap in the U.S. since 2006. Right now, Tdap vaccines are only licensed and recommended as a single dose. We’re still working to understand how Tdap protection declines over time or might differ based on which vaccine was received during early childhood (i.e., DTaP or DTP). All adults are recommended one dose of Tdap as soon as possible, especially if pregnant or in close contact with infants. In the future, additional doses might be recommended.

10. Question from viewer “Ryan Johnson”: [[Your Top 10 Things to Know About Whooping Cough list](http://www.pbs.org/newshour/rundown/2012/08/whooping-cough-outbreak-top-10-things-you-should-know.html) states,] “The best way to know if you have pertussis is to see your doctor, who can make a diagnosis and prescribe you antibiotics, if recommended.” So what’s the second best way to know for those of us who don’t have insurance or access to a doctor?

Clark: While pertussis can be serious at any age, infants are at greatest risk for severe or even life-threatening disease. Any parent who is worried that their child has signs or symptoms of an emergency condition should seek medical attention immediately. U.S. law requires emergency departments to determine if a patient has an emergency condition and to provide them sufficient treatment. For others, your state or local health department may be able to help identify a health care provider who treats those who are uninsured and have limited ability to pay.

11. Question from viewer Kennetha Scott: Why isn’t there anything on the CDC website about Tdap waning???? Why don’t they share their message directly with the public? They have known for quite a while that Tdap isn’t long-lasting, yet they failed to notify the public. None of this is new information. They knew it in 2010 and before. This is a CDC and DOH failure to spread their own message because it costs too much. Plain and simple. If they would have been proactive, we wouldn’t have this problem. Why aren’t they monitoring it more closely, when they have knowledge that the vaccine is not working as advertised?

Clark: Tdap, the adolescent and adult pertussis booster, has only been used in the U.S. since 2006. We have no measure of waning protection from Tdap. In the 2010 epidemic in California, disease rates were not elevated in adolescents. Observations of the current pertussis epidemic in Washington state were published in July. Unlike in 2010, observations of increased risk in adolescents in 2012 suggests that Tdap protection in those who got DTaP as children may be different or may not last as long as in those who got DTP. It will be important to understand the reasons for this, which is the focus of current evaluations. Right now, Tdap vaccines are only licensed and recommended to be given once, but in the future additional doses might be recommended.

12. Question from viewer Tracy Abeln: “I have never-ever heard from my doctor, ‘You should consider this vaccination as an adult,’ or have had any medical professional mention it or even ask whether or not I was spending time around babies, etc.” Are doctors doing enough to spread the word about the Tdap vaccine and potential risks of pertussis?

Clark: In general, adults are not receiving recommended vaccines as recommended. They often don’t see doctors on a regular basis or may not have time at that visit for the vaccine conversation. We urge doctors to make adult vaccines part of the conversation, especially for pregnant women or those in close contact with infants. We also hope that patients are hearing more about whooping cough through programs like PBS or other outreach efforts to then ask their doctor or pharmacist for the Tdap vaccine. There’s a lot of room for improvement; as of 2012, only 8.2 percent of adults had received their Tdap booster shot.

As you observe, there are many factors that contribute to the low coverage with Tdap in adults. Hearing stories about pertussis in their own communities and about how dangerous it can be for babies may help people to realize the need for vaccination talk to their doctors about getting vaccinated.

13. Question from viewer “Schiffer Kathy”: My son was born in 1987 when the American Pediatric Assn. published a warning that the dosages of the pertussis vaccine could vary from vial to vial by 10 times. They notified parents to be aware of some neural symptoms of their recently vaccinated infants. My son had a neural reaction to his second vaccine. I did not allow him to have any more after that. I understand that the vaccine is in a different form now and at the age of 25, I wonder if it is safe for him to have a booster vaccine.

Clark: In some children, neurologic conditions developed after they received a dose of whole cell pertussis vaccine (DTP). These neurologic conditions were rare, but were sometimes permanent. Even though DTP vaccines were phased out in the U.S. in the 1990s and replaced with safer acellular vaccines (DTaP), any child who developed a neurologic condition within seven days of receiving a dose of a diphtheria, tetanus and pertussis vaccine that could not be attributed to another cause is recommended to not receive another vaccine against pertussis. Your son should discuss this with his doctor to determine what is best for him.

14. Question from viewer “PBS Guest: If a child had a reaction to the second shot in the pertussis series (DTaP) and no more was given because of the severe reaction, should the 28-year-old get the adult vaccine now?

Clark: Children with a history of severe allergic reactions or of neurologic conditions as noted above following a dose of pertussis vaccine are recommended to not receive another dose. Those who have had other serious or severe conditions develop after vaccination should discuss this with their doctors. Those who had local reactions like pain or swelling, even if they were serious enough to limit activities, generally can be vaccinated again. It’s important to discuss your individual situation with your doctor.

15. Question from viewer Jane Willis: My company consists of speech therapists, occupational therapists, and physical therapists. Our pediatric therapists work with kids mostly 2-5 years old, but we also have some contact with infants and older kids. My own group of pediatric therapists work in inner-city child development centers. Other therapists work with the elderly. We work in Minnesota and neighboring states. Question 1) Should we be getting the new pertussis vaccine to protect ourselves and others? I myself am 65. My physician father told me I had had all my childhood vaccinations. I don’t know whether that included pertussis at that time. Question 2) Should I be getting the new vaccine or just a booster?

Clark: 1) All adults should be getting the Tdap booster shot, especially health care workers and those who work with or care for infants. 2) Even if vaccinated as a child, adults still need to get the Tdap booster shot. Protection from pertussis vaccines wears off over time. There is only one pertussis vaccine licensed and recommended for adults; it’s called the Tdap booster shot. Adults can get it regardless of their childhood vaccination history.

16. Question from viewer Irma Ascher: I am a senior citizen (over 70) who actually had whooping cough when I was a young child before there existed any vaccination. I am assuming that having had the disease that long ago means that I no longer have any immunity (but I’m not sure). I also was told by a doctor who gave me some shots before a trip to the Ukraine some five or six years ago, when there was a considerable amount of whooping cough in that country, that the likelihood of my contracting the disease during the trip was smaller than the likelihood that I would have “bad” effects from the pertussis inoculation, and I did not get the shots. One month from now, I’m going to Vashon Island, Washington (just off the coast of Seattle) for my grand-nephew’s wedding (a 2-day affair), just where the whooping cough epidemic seems to have hit the hardest, according to tonight’s NewsHour report. So my questions are: 1) Should I try to get the vaccination before I go? 2) Is it dangerous for me to get it, as that doctor intimated a few years ago? 3) Should my almost 50-year-old daughter (who I assume had the vaccination as an infant) get vaccinated again, as she is also going to the wedding celebrations at Vashon? 4) What about her 15-year-old twins, who are also going; is their infant vaccination still protecting them, or do they need a booster? I would be most grateful if you could get these queries answered by the people by the people at CDC.

Clark: 1) All adults are recommended a Tdap booster shot. It can take about 2 weeks for immunity to build up after getting the vaccine. So you should talk with your doctor about getting it, preferably before your trip to Washington. 2) Tdap vaccines are very safe and generally well-tolerated. Like any vaccine, there are side effects associated with Tdap — most commonly local reactions like pain or swelling at the injection site, but these get better in a few days on their own. Serious adverse events are rare. You can read about them on the Vaccine Information Statement. 3) Please see the answer to your first question. 4) All adolescents are recommended a dose of Tdap, preferably at age 11 or 12 years. Any adolescent who didn’t get Tdap at age 11 or 12 is recommended a dose as soon as possible. Protection from infant/childhood pertussis vaccines decreases over time.

17. Question from viewer: “Whooping cough cases are higher among those who are vaccinated versus those who aren’t. The vaccine’s long-term effects are admittedly unknown also. So why are doctors and media mindlessly pushing vaccines on an unknowing public?” Why are most of the cases among those who have been vaccinated and should more attention be paid to this fact?

Clark: Vaccination is one of the great successes of public health. Before vaccines, as many as 200,000 cases and 9,000 deaths from pertussis occurred each year in the U.S. Non-vaccination puts children at risk for pertussis. Unvaccinated children are at least 8 times more likely than those who are vaccinated to get pertussis. In unvaccinated children, pertussis can be a severe disease at any age. As described above, it is common to find that the majority of pertussis cases occur in vaccinated children because vaccine coverage is high but protection decreases over time. Keeping up-to-date with recommended pertussis vaccines is the best way to protect you and your loved ones.

18. Question from viewer Kanprimate: Thank you for your story regarding the vaccine debate. I would like to get vaccination against whooping cough and a number of other contagious diseases but, due to egg allergy, I cannot. People like myself, through no fault (or choice) of our own, are vulnerable to these preventable diseases and, ironically, we are also potential carriers of infection. I am particularly anxious about this issue because I am a college instructor and an outreach science educator in public K-12 schools. Could I be more vulnerable; could I be more dangerous? When the mother in tonight’s news story claimed that she could protect her children against this disease without vaccination, I shuddered. I hate the fact that my health, and the health of individuals with whom I have contact, is dependent on parental vaccination choices. I have seen college students with whooping cough, meningitis, and measles and I have seen grade schools under “flu alert.” I wish that parents who choose not to vaccinate their children could spend a school year in my shoes! Please keep reporting on this issue and could you please report on the use of eggs to culture vaccines? Wouldn’t it extend vaccine shelf-life if another medium was employed?

Clark: While eggs are used in the production of certain vaccines, they are not used to make whooping cough vaccines or many other vaccines. You should talk with your doctor about which vaccines you are recommended to receive.

19. Question from viewer: My understanding is that after one has taken a course of antibiotics one is no longer infectious for pertussis. Is that correct?

Clark: After taking the recommended course of antibiotics to help treat your pertussis infection, people are considered no longer contagious. This is why it is often recommended that people who have pertussis limit contact with others until they have been on antibiotics for five days.

20. Question from viewer: Can people catch whooping cough repeatedly, as in every time they catch colds throughout the year, or does the body build immunity in the short-term?

Clark: Having whooping cough is thought to protect for anywhere from 4-20 years, but does not provide lifetime immunity. So anyone who had pertussis is still recommended to get pertussis vaccines.

Related Coverage

Top photo shows Chelsey Charles comforting her daughter, Kaliah, who died last summer at 27-days-old after catching pertussis. Photo courtesy of Chelsey Charles.