It depends on whether or not the kids have any kind of serious allergic reaction to the vaccinations.
This is a good point. About every 10 years for several years now, I've updated my tetanus vaccination. Last Dec, I went in for a fresh tetanus vaccination because it was close to the 10 year limit since I had received the previous dose.
I did have a reaction to the vaccine. My arm turned red and was tender for some time following the shot. This was the very first time I'd had a reaction to the tetanus vaccination. Since then, I've often wondered if the shot I received was really a tetanus shot. I also wonder if at the end of 10 years, I'll go back for another tetanus shot.
Your first dose of the polio vaccine was by injection ( Salk method) and I remember that some kids later developed polio after receiving this attenuated vaccine.
Luckily, the Sabin vaccine was developed .