resurgence of pertussis

The resurgence of pertussis (whooping cough) occurs because immunity from childhood vaccination can diminish over time, leading to more teenagers and adults becoming susceptible again. Additionally, the bacteria evolves, sometimes making vaccines less effective. Some vaccinated individuals may still carry and spread the bacteria without showing symptoms. Changes in vaccination coverage and vaccine types, as well as increased awareness and better detection, can also contribute to observed increases. Overall, these factors combined can result in more cases of pertussis despite ongoing vaccination efforts.