I recently had a 10-year tetanus booster and learned that it’s not known if they are necessary, but they don’t hurt (except for the sore arm), so they’re given

I recently had a 10-year tetanus booster and learned that it’s not known if they are necessary, but they don’t hurt (except for the sore arm), so they’re given at ten year intervals. It’s really unclear what the goal is with this campaign. My wife and son recovered last year and has not received a Covid shot. When others in our family caught it 9 months later, they didn’t get sick, as expected, and had an appropriate and measurable antibody response.