One big difference between smallpox and COVID is that if you got smallpox (and lived) you had lifetime immunity. That made it possible to develop a vaccine that also gave lifetime immunity. Once you have had COVID you can get it again (I have had it twice). So the best we can hope for with COVID is a leaky vaccine.
Curious, did you get vaxed after getting Covid the first time? Asking because I had it real bad and was hospitalized for three weeks back in February and March and haven’t been vaxed yet