'We make it so to' fund NASA and the DOD and a host of other Federal agencies.
Your assertion that we don't need herd immunity is contrafactual junk science nonsense.
That herd immunity is why we don't worry about polio, measles, cholera and smallpox; but, alas, no such immunity is possible against stupidity and willful ignorance.
Herd immunity created via vaccination contributed to the eventual eradication of smallpox in 1977 and has contributed to the reduction of other diseases.[9] Herd immunity applies only to contagious disease, meaning that it is transmitted from one individual to another.[7] Tetanus, for example, is infectious but not contagious, so herd immunity does not apply.[6]
Herd immunity was recognized as a naturally occurring phenomenon in the 1930s when it was observed that after a significant number of children had become immune to measles, the number of new infections temporarily decreased.[10] Mass vaccination to induce herd immunity has since become common and proved successful in preventing the spread of many infectious diseases.[11] Opposition to vaccination has posed a challenge to herd immunity, allowing preventable diseases to persist in or return to populations with inadequate vaccination rates.[12][13][14]
Vaccines lose effectiveness over time. In other words, the smallpox vaccine you received as a child is actually no long effective in fighting smallpox.
The only reason we don't have to actively worry about catching it is that it's been wiped out because, and only because, everyone's been vaccinated.
There's no cure for smallpox other than mass, mandated vaccinations.