Whooping cough — known medically as pertussis — is a highly contagious respiratory tract infection. Although it initially resembles an ordinary cold, whooping cough may eventually turn more serious, particularly in infants. The best way to prevent it is through vaccinations.

The best way to prevent pertussis (whooping cough) is to get vaccinated. There are vaccines for babies, children, preteens, teens, and adults. The childhood vaccine is called DTaP, and the pertussis booster vaccine for preteens, teens, and adults is called Tdap.

Pertussis vaccines are effective, but not perfect. They typically offer good levels of protection within the first 2 years of getting vaccinated, but then protection decreases over time. This is known as waning immunity. Similarly, natural infection may also only protect you for a few years.

The current estimate is that in the first year after getting vaccinated with Tdap, it protects about 7 out of 10 people who receive it. There is a decrease in effectiveness in each following year. About 3 or 4 out of 10 people are fully protected 4 years after getting Tdap.