[nradov]

We eradicated smallpox and (almost) polio because there were no animal reservoirs and the vaccines were highly sterilizing. Those criteria do not obtain with SARS-CoV-2. Many other mammal species can catch and spread the virus. The original bats which presumably transmitted it to humans are still out there. And vaccinated people can also still catch and spread the virus; there is probably some reduction in contagiousness but the magnitude is unclear.