Whooping cough, also known as pertussis, is a highly contagious respiratory disease caused by the bacterium Bordetella pertussis. It is known for uncontrollable, violent coughing which often makes a “whooping” sound when the person breathes in. Whooping cough can affect people of all ages, but it can be very serious, even deadly, for young babies.
Getting vaccinated is the best way to prevent whooping cough. The whooping cough vaccine is included as a component of the combined diphtheria, tetanus, and pertussis (DTaP) immunization. The DTaP vaccine is recommended as a five-dose series at 2, 4, 6, 15-18 months, and 4-6 years old. An additional Tdap booster is recommended between age 11-12 to help protect adolescents and adults from pertussis.
The big question is: does the whooping cough vaccine provide lifetime immunity against the disease? Or does the protection from the vaccine wear off over time?
The protection from the childhood DTaP vaccine decreases over time
The DTaP vaccine is very effective at protecting children from whooping cough. However, research shows that the immunity provided by the vaccine decreases over time.
Several studies have found waning immunity approximately 5-10 years after the 5-dose DTaP series is completed in childhood. One study found that the odds of contracting pertussis increased by 42% for every year elapsed since the last DTaP dose. Another study estimated that protection from the DTaP vaccine only lasted for 4-12 years.
This waning immunity is not unexpected – most vaccines lose some effectiveness over time. The immunity boosting cells (memory B-cells) and antibodies stimulated by the vaccine gradually decline. As a result, people become vulnerable to whooping cough again several years later if they are not re-vaccinated.
The decrease in protection provided by the childhood DTaP vaccine highlights the importance of the Tdap booster shot recommended between ages 11-12. Getting a booster shot in pre-adolescence provides another immunity boost right before entering the age range where pertussis risk starts increasing again.
Tdap booster shots are crucial to maintain protection through adulthood
While the protection from the childhood DTaP vaccine wanes after 5-10 years, receiving the recommended Tdap booster between ages 11-12 provides longer lasting immunity through the teenage years.
Studies have found that 5-10 years after receiving the Tdap booster shot in pre-adolescence, around 80-85% of teenagers still have protective antibody levels against whooping cough. This is a significantly higher level of protection compared to those who only received the childhood DTaP vaccine series.
It is very important that adolescents receive the Tdap booster, as evidence shows childhood DTaP protection sharply declines after age 12. Whooping cough risk increases in adolescence, especially in middle and high school when students are very close together for many hours per day. The Tdap booster offers an immunity boost right before entering this high risk period.
Additional Tdap boosters are recommended every 10 years during adulthood or with every pregnancy. Getting regular Tdap boosters throughout adulthood is crucial to maintain protection against whooping cough over the lifespan.
Frequent boosters are needed to sustain protection
Based on the current evidence, whooping cough immunity does not last for life after getting vaccinated. This applies to both the childhood DTaP series and adolescent/adult Tdap boosters.
Protection provided by the DTaP vaccine starts decreasing 5-10 years after the series is completed. The pre-adolescent Tdap booster extends that protection through the teenage years, but also appears to wear off over the following decade.
This data indicates that whooping cough immunity gradually wanes in the years after vaccination. To sustain protection throughout adulthood, more frequent Tdap boosting is needed.
The CDC currently recommends Tdap boosters every 10 years. But some experts think a booster interval of 5 years may be more effective, based on studies showing immunity decline after 5 years.
Some countries have already adopted 5-year booster intervals for adults, including Canada starting in 2018. More frequent boosters will provide more consistent protection throughout adulthood against this dangerous illness.
Vaccination protects against severe disease, even if not long-term immunity
While immunity from the whooping cough vaccine wears off over time, vaccination still provides major benefits against the disease. Getting vaccinated substantially reduces the risks of severe outcomes from pertussis compared to being unvaccinated.
Many whooping cough cases in vaccinated individuals tend to be milder with fewer complications. Adults who received the childhood DTaP vaccine series followed by a Tdap booster have an over 90% lower risk of hospitalization and serious complications compared to unvaccinated adults. The vaccine provides long-term protection against severe disease.
Vaccination also reduces the duration of whooping cough illness. In vaccinated individuals who catch pertussis, symptoms tend to be more transient compared to unvaccinated cases. Vaccination helps the immune system mount a faster, stronger response upon re-exposure to control the infection sooner.
Although immunity wanes years later, the whooping cough vaccine still offers major short and long-term health benefits. Maintaining up-to-date pertussis vaccination status, including boosters, remains the most effective way to prevent this dangerous disease.
New vaccines in development may provide longer-lasting immunity
Because protection from the current DTaP and Tdap vaccines decreases over time, researchers are working to develop new pertussis vaccines that provide longer-lasting immunity.
Some experimental vaccines being studied contain new vaccine ingredients (adjuvants) that may prolong the immune response. Other approaches focus on delivering immunogenic pertussis antigens in different ways to improve the durability of protection.
Potential new vaccine technologies undergoing clinical trials include:
– Whole cell-based vaccines – May stimulate broader, more sustained immune responses than acellular vaccines.
– Live attenuated vaccines – Use weakened live bacteria to provoke strong cellular immunity.
– Outer membrane vesicle vaccines – Use pertussis membrane components to enhance antibody response.
– Maternal immunization – Provide passive immunity to infants through vaccinated pregnant women.
– Novel adjuvants – Boost immune stimulation using new compounds like TLR-4 agonists.
It will likely take years of further clinical research before any of these new pertussis vaccines become available. But the development of a vaccine that provides long-lasting or even lifetime protection against whooping cough remains an important goal.
Booster compliance is challenging but critical
For sustained protection against whooping cough, receiving timely booster shots throughout life is essential. However, many adolescents and adults are not compliant with the recommended 10-year Tdap booster schedule.
Studies show adolescent Tdap booster uptake lags behind vaccines recommended at younger ages. Only about 15% of adults 19+ years old reported receiving their recommended next Tdap booster dose. Such low booster compliance undermines population-level pertussis immunity.
Achieving higher booster shot compliance presents an ongoing public health challenge. Reminder-recall systems, expanded pharmacy vaccination services, and education programs can all help increase booster adherence. Healthcare providers also need to consistently recommend ongoing Tdap boosters to patients during adulthood.
Receiving regular pertussis vaccine boosters, starting with the pre-adolescent Tdap dose, remains the best way for individuals to stay protected against whooping cough over their lifetime. From a public health perspective, improving booster compliance rates will help control the continued circulation of this highly contagious disease.
Conclusion
Based on a review of the evidence, immunity from the whooping cough vaccine does not last for a lifetime. Protection starts decreasing 5-10 years after the childhood DTaP series is completed. The Tdap booster extends that protection through adolescence, but it also appears to wane over the next 5-10 years without additional boosting.
To sustain immunity throughout adulthood, more frequent Tdap boosters every 5-10 years are needed. While the protection from vaccination is not permanent, getting vaccinated still substantially reduces the risks of severe pertussis disease compared to being unvaccinated.
New pertussis vaccines that may provide longer-lasting protection are currently in development. In the meantime, promoting higher booster shot compliance rates remains critical to help prevent continued whooping cough outbreaks. Although whooping cough vaccine does not confer lifetime immunity, maintaining up-to-date pertussis vaccination including regular boosters is still the best defense against this dangerous illness.