Ah, you are looking at the wrong info.
Maybe
@Dirty Dog has a professional answer, but the Vaccine is just that, a vaccine, not a shot.
And I have not heard of a resistance to vaccines being developed by using one. Rather resistant strains are being bred by people who do not vaccinate and merrily spread the vorus about the community.
The Alpha variant was believed to slowly mutate about every 30th infection, a minor change
Now, however after we have seen several accelerated waves and several new variants (Lamda is the one to look out for) who knows.
You get a tetanus shot when you step on a rusty nail don't you, even if the previous booster was less than 10 years out.
And BTW, Tetanus, when started from scratch has a similar schedule as now suggested for COVID shots: 1sr and 2nd a month apart, then 6 months later a third shot. 10 years after that, or whenever a critical injury (like rusty nails) occurs.
What is the regimen for your lifestock? Spring shots, whether they are actually 'needed' or not.
because the ounce of prevention.....