Tetanus

An elderly man get up and puts on his coat, telling his wife he is going to the doctor.

Surprised, his wife asks, “Why, are you sick?”

“No,” he says. “I’m going to get me some of those new Viagra Pills.”

With that, his equally elderly wife gets up out of her rocker and starts putting on her sweater.

Surprised, he asks, “Where are you going?”

“I’m going to the doctor, too… If you’re going to start using that rusty old thing again, I’m going to get a tetanus shot.”