Whoop, there it is.
That vaccine preventable illness called pertussis, the one that causes the “100-day cough” with the characteristic “whoop,” is making a comeback.
Cases of whooping cough, also known as pertussis, are rising nationally and across California. According to the California Department of Public Health, during the first three quarters of 2025, pertussis cases in infants under four months of age increased by 54%.
What is whooping cough?
While many people have heard of whooping cough, most are not aware that this deadly bacterial illness still exists and is spreading.
Whooping cough is caused by a very contagious type of bacteria, Bordetella pertussis, which infects the respiratory tract, causing a disease with three phases that may last for more than 100 days.
The first phase looks just like the common cold: runny nose, sneezing and mild cough. This is the most contagious phase and may last up to two weeks.
In the second phase, the cough becomes more intense, leading to rapid sequences of coughs. A characteristic “whoop” signals the desperate need to breathe. Very young infants may not “whoop,” but may turn blue and stop breathing. This coughing phase can last up to four weeks and is the time when most complications arise.
During the final phase, the debilitating cough nags and slowly subsides over the course of several months.
Complications
Complications from pertussis are numerous and include pneumonia, seizures, permanent brain damage or even respiratory failure and death. Infants under six months of age are at the highest risk for these complications.
Treatment
By the time whooping cough is typically diagnosed, little can be done to change the course of the disease. Treatment is largely limited to supportive care. Hospitalization is needed for children with severe coughing associated with pauses in breathing or lack of oxygen. A breathing tube and a ventilator may be required for infants who stop breathing, have respiratory distress or develop pneumonia.
Antibiotics are given to infected patients and close contacts to minimize contagiousness and reduce the spread of disease. But unless taken very early in the illness, antibiotics are not really effective in shortening the severity or length of illness.
Prevention
Universal immunization with pertussis vaccine is recommended for all children, teens, pregnant women and adults. This vaccine is safe and effective for infants as young as 6 weeks of age.
Pertussis is the “P” part of the DTaP and Tdap immunizations. Children should receive the DTaP vaccine at 2, 4, 6 and 15 months of age, followed by a booster between 4-6 years and Tdap at 10 or 11 years of age. Additional Tdap boosters may be recommended for adults every 5 to 10 years and for pregnant women with each pregnancy.
Infants who are infected with pertussis often catch it from a parent or close family contact. So if you are a new parent, nanny, grandparent or someone else who takes care of babies, you should talk to your health care provider about a booster.
Vaccines are safe and necessary
Vaccines have been so effective in reducing childhood diseases that some new parents may have a false sense of security and no longer see the need to immunize their children. In communities where childhood immunization rates are declining, vaccine-preventable diseases are making a comeback.
When more than 95% of children and adults within a community are immunized against vaccine preventable diseases, we achieve what is called “community immunity” and we significantly reduce the chances of having community outbreaks.
Not everyone develops immunity from vaccines, so having high immunization rates is essential to protect all members of our community, including those who have a suppressed immune system, elderly, pregnant women and babies who are too young to be immunized.
Childhood immunizations are safe and effective and do not cause developmental delays.
The science has not changed
The most common question heard in pediatric offices these days has to do with vaccine schedules, vaccine availability and vaccine coverage.
There is good news!
Thanks to AB 144, Californians will continue to follow the childhood vaccine schedule published by the American Academy of Pediatrics. Vaccines and coverage for vaccines will remain available as well.
If your child is not fully immunized or if you are a teen or adult or pregnant mom who may need a Tdap booster, please contact your doctor and avoid the chances of getting “whooped.”