My friend, the one with whooping cough who passed it on to her kids? She’s now wanting to be “better safe than sorry,” recommending people get tested, or get the booster if you’re an adult with intent to go anywhere near an infant or another with compromised immunity.

She just didn’t know how serious pertussis was, and how the vaccine is the only thing that prevents it.

Tough lesson to learn, as she and her children remain very ill — the kids won’t be returning to school until they stop throwing up from all the coughing, and she and her husband will miss some work over the next several weeks caring for them.

But it’s a lesson learned. And brightly.