The incontrovertible fact is that smallpox declined with declining vaccination rates, not only in the UK but throughout the world. (cf Figs I and II) From 1919-1927 there were 0.46 deaths per million from smallpox in England & Wales where vaccination had declined considerably. The
corresponding rates 'for Czechoslovakia, Roumania, Spain, Italy and Portugal, all of which had universal vaccination and re-vaccination were:

10.3, 23.4, 47.4, 65.7,101.1, and 386! Mortality from smallpox in vaccinated Spain was more than 80,000% higher than in relatively unvaccinated England & Wales. Smallpox was virtually unknown in unvaccinated Australia and the disease was eradicated from Mali and Sierra Leone, where they previously had the highest smallpox rates in the world, with only 51 and 66% vaccination rates. We may also deduce from Figs I and II that if vaccination reduced mortality from smallpox then non-vaccination did the same for other diseases.