It is less crucial for adults, ....
This is wrong, David. Whooping cough (pertussis) vaccine actually has a different goal than most vaccines.
Herd immunity is the primary mechanism of protection. Individual immunity is secondary.
Here's the deal. Most fatalities occur in kids under a year old. At that age, even with the routine vaccine schedule, the vaccine is not going to be providing adequate protection in many kids. The doses are given at 2, 4, and 6 months with another booster at 18 months. So half the kids under a year (those under 6 months) are not protected.
That means with whooping cough vaccine, the goal is to vaccinate the people who the infant comes in contact with, and to interrupt the annual epidemic cycle.
But, until a few years ago, there was not a vaccine available for kids over age 7. So we all got our vaccine as kids, then a decade or two later, we started seeing cases in teens and young adults. The epidemic cycle restarted.
Now there is a safe adult whooping cough booster. You should get that booster (if you haven't already) with you next tetanus shot. Tetanus vaccine is due every 10 years. A child on schedule with vaccines would get the booster about age 15 yrs.
If you are around infants, and you haven't had the one time dose of tetanus vaccine with whooping cough vaccine, you should consider getting the tetanus booster with whooping cough vaccine sooner than the 10 yr interval.