It's nonsense. A focused containment vaccination strategy makes perfect sense. You could have prevented the Chicago fire by hosing down Mrs. O'Leary's barn in advance of her cow kicking over the lantern. You wouldn't have needed to hose down the whole town in advance. A reliable vaccine (available c. 1950), that strategy and the willpower and $ to implement it were quite sufficient to end smallpox 'in the wild.'
It is easy to prove smallpox has been extinct in the wild. It has no natural host other than man. It can't survive outside live people long, at least not in the tropical or temperate climates suggested upthread. I've heard zero claims for ongoing smallpox epidemics in Alaska. Variola major averages 30% mortality, variola minor about a tenth of that and both are fairly contagious. To survive 'in the wild' Smallpox has to kill people and it does so quickly. We've been making zero effort to defend against it for 20+ years so most of the world is susceptible. If it were still around LOTS of people would be dying. In the late 60s it still killed over a million people each year. Even in Africa today that WOULD get noticed. Even Clinton couldn't coverup the presence of uncontrolled smallpox in the world. Smallpox stored in a lab someplace is the only legitimate concern.
There are lots of _____pox animal viruses at least loosely related to smallpox. Like smallpox they tend to be quite picky about which species they attack. Monkey pox is the only significant concern. It's not very contagious to people, rarely kills them, and lab tests can tell it from smallpox. Human camelpox is a negligible risk. The risk of camel kicks, camel bites and camel spits is far greater.
Only if the vaccine works. And the numbers do not support the data. Quite the opposite is true. I notice that you ignore the data from London's own registry. Convenient for you but not very convincing. If vaccinations are to be considered scientifically sound, then there should be some data to support the theory that they erradicate or slow disease rates. There isn't any. Such data cannot be produced.
The polio vaccine is another fine example of propaganda not quite matching scientific data. It is a fact that there hasn't been a single case of polio in the United States since 1970 that wasn't related to exposure to the vaccine. There is data to suggest that the date can be pushed back to 1954 but the later date is damning enough.