A study published today in The New England Journal of Medicine evaluated the duration of protection against whooping cough after children get the DTaP shot. Researchers wanted to find out how long the shot lasts. DTaP shots are given to infants, toddlers, and kindergarteners (schedule below) to protect them from three infections (Diptheria, Tetanus, and Pertussis –whooping cough). After these childhood vaccines, we give a “booster” shot at age 11. Because we know that many babies who get whooping cough are infected by teens and adults, all teens and adults are now recommended to get a Tdap shot to protect themselves and those vulnerable against whooping cough.
As researchers seek to understand the recent epidemics of whooping cough in the US, they have found more and more that the causes of these epidemics are multifactorial. Not only is it unvaccinated populations that allow epidemics, it may be waning immunity from shots given previously and waning immunity to natural infection, as well. Previously, it’s been estimated that our immunity to whooping cough wanes anywhere between 4 and 20 years after we get whooping cough, and that it may wane 4 to 12 years after the shot.
A little history: back in the 1990’s we switched from using the “whole cell pertussis” shot to using a vaccine that is “acellular.” Some health officials have had concerns that this “acellular vaccine” may not protect children as long. Although it does a great job protecting infants and toddlers, it may not last as long as previous immunizations. Some have wondered how long the kindergarten shot protects our children…
Physicians at Kaiser Permanente reviewed information about children in California during the 2010 whooping cough outbreak. What they found may have significant effects on how to protect our children going forward:
Timing Matters: Waning Protection After 5Th Dose:
- Design: Researches compared 277 children with lab-tested whooping cough between 2006 and 2011. They compared the children with whooping cough to nearly 10,000 controls (children who tested negative for pertussis & children who were matched controls).
- Results: Children who were diagnosed with whooping cough were more likely to have had the Kindergarten dose earlier. More of those who ended up getting whooping cough may have had the shot when they were just 4 years of age. The next booster isn’t until age 11 years so in the 7 years between the shots, their immunity may have waned.
- Conclusions: After the 5th dose of whooping cough shot (DTaP), the odds of acquiring pertussis increased by an average of 42% per year. This means, for every year that passes after a child gets the Kindergarten shot, the likelihood that they could get whooping cough may increase until the next booster.
What To Do To Help Protect Your Family From Whooping Cough
- We still know the best way to protect against whooping cough is to get everyone in your family immunized. If we immunize our babies, toddlers and infants per the schedule, and get the updates as adolescents and adults, we reduce the likelihood for infection in all. We also know that as time unfolds we may need additional boosters.
- Booster shots “boost” your child’s and your family’s immunity. Stay up to date. Here’s a post from Dr Ed Marcuse on pertussis boosters. The data from this NEJM study may help the CDC and the American Academy of Pediatrics better know when to recommend that our children get the next booster.
- Keep learning. It’s a part of being human to lose immunity to infections, both from natural infection and from vaccines. Over time, our bodies forget how to protect against infections. This study points out that the new generation of children who have had only “acellular” pertussis vaccines may need additional boosters to keep them safe. Time will tell. New recommendations may come out later this year or next.
Does this make sense? Tell me what I can explain…
Vanessa says
What is the difference between the “whole cell pertussis” & the “acellular” shot? Why was it changed?
Wendy Sue Swanson, MD, MBE says
Here’s how Dr Marcuse (a vaccine expert)explained it:
Siobhan M Palmer says
Is there a blood test to check a child’s immunity after a few years so they can be revaccinated earlier than age 11 if necessary. Would this be advisable?
Wendy Sue Swanson, MD, MBE says
Siobhan,
You ask a really great question. The short answer is “not a really good one” that is not cost-prohibited.
In general, you can do serologies (blood titers) that measure antibodies for many types of infections, but in general when it comes to pertussis there isn’t an easy one.
Here’s a link to the CDC that discussses this https://www.cdc.gov/pertussis/clinical/diagnostic-testing/diagnosis-confirmation.html
And here’s what they say:
Sue says
For those of us who received the original whole-cell vaccine, do we need to get a booster? How long does it take for that vaccine to wane? I was one of those unfortunate children who suffered a severe reaction to the original DTP vaccine and have been told not to get the vaccine again. I would appreciate any feedback you can give. Thank you.
Wendy Sue Swanson, MD, MBE says
Hi Sue,
Thanks for your question. If you have had a reaction to the DTaP vaccine, it’s best you talk with your own doctor. If you’ve had a severe reaction, it’s unlikely that it will be recommended. However, this makes it all that much more important that all those around you are immunized.
Here’s info from the CDC on those who shouldn’t get the shot: (https://www.cdc.gov/vaccines/vpd-vac/should-not-vacc.htm#td)
Anyone who has had a life-threatening allergic reaction after a dose of any tetanus, diphtheria, or pertussis containing vaccine should not get Td or Tdap.
Anyone who has a severe allergy to any component of a vaccine should not get that vaccine. Tell your doctor if the person getting the vaccine has any severe allergies.
Anyone who had a coma, or long or multiple seizures within 7 days after a dose of DTP or DTaP should not get Tdap, unless a cause other than the vaccine was found. These people may get Td.
Talk to your doctor if the person getting either vaccine:
has epilepsy or another nervous system problem,
had severe swelling or severe pain after a previous dose of DTP, DTaP, DT, Td, or Tdap vaccine, or
has had Guillain Barré Syndrome (GBS).
Anyone who has a moderate or severe illness on the day the shot is scheduled should usually wait until they recover before getting Tdap or Td vaccine. A person with a mild illness or low fever can usually be vaccinated.
Sue says
I forgot to mention that three of our five children caught whooping cough four years ago (from their vaccinated sibling), and my husband and I did not catch it. We have not received any boosters since we were young children.
Sue says
Should my husband who received the whole-cell vaccine get a booster? It is my understanding that those who have receved the whole-cell vaccine are not contracting whooping cough, only those who have received the acellular version. Our children who had been fully vaccinated with the acellular vaccine contracted whooping cough four years ago. My husband and I (who have been vaccinated with the whole-cell vaccine) did not get it. Thank you again for your time.
Jennifer Walker says
Hi Sue,
I received the DTAP last Dec. after a dog bite. We were certain I had not been vaccinated in many decades as I was 54 at that time. This said vaccine was administered on a Friday evening with out any discomfort.on Sunday morning I awoke to a very sore arm. Was this the expected time lapse for the normal reaction? Then on Tuesday I began having strange tremmors and a weird feeling deep in my body. By 8:00 pm I spiked a temp and went to bed shaking with nausea and all over body pain. I was flat out immobilized for 5 days ,a103 temp the first 3 days then slowly able to get out of bed without pain and could finally start to eat on day 5. They did not give me an antibiotic in the emergency room the night of the dog bite. My GP said due to the deep puncture wond I sustained she would have. I ended up with an infection after 2 weeks and still have itching and irritation at the bite site.
My 64 year old sister just got diagnised with whopping cough after being in Mexico. We are traveling there in Dec. I now know I’m protected.
Did the fever etc. come from the bite or the DTAP? Would you please weigh in?
Thanks for your time.
Courtney says
My family got the pertussis vaccine 4 years ago when my son was born, just had another baby, should they get another?
Wendy Sue Swanson, MD, MBE says
in the US pregnant moms are recommended to get the Tdap vaccine (for pertussis) during the 3rd trimester of every pregnancy. Therefore yes, if you’re pregnant talk with your OB about a Tdap during this pregnancy
https://www.cdc.gov/pertussis/pregnant/mom/get-vaccinated.html