The smallpox vaccine was one and done, for life. I had one when I was born, and was never offered another.
Actually that's not exactly correct.
CDC - Smallpox Vaccine Basics
Smallpox vaccination can protect you from smallpox for about 3 to 5 years. After that time, its ability to protect you decreases. If you need long-term protection, you may need to get a booster vaccination. Find out who should get smallpox vaccine.
It offered very robust protection for 3-5 years, then the protection gradually diminished. Re-vaccination would be done in areas with an outbreak before the virus was eradicated.
I got the smallpox vaccine in 1971 (just before entering the 1st grade if I recall correctly) and it was discontinued in the US the next year I believe. I once looked into how much protection my '71 vaccine might offer me today, 52 years later. The answer is, maybe a very small amount but not that much. The immune system does forget after enough time.
The reason we never needed a booster is that smallpox was becoming increasingly uncommon in the wild by the 1960s and almost unheard of in the developed world. So, you and I were very unlikely to encounter it. And of course, it had become so rare in the West that most European countries and the US/Canada stopped requiring vaccination in the early 1970s.
The last naturally acquired case of smallpox was in 1977 (had to look that one up).
You have to be of a certain age to remember the round quarter sized scar that every kid sported on his upper arm that he got from his smallpox vaccine. Whenever I got out in the sun and got a tan there was always that round spot near my shoulder that remained stubbornly pale. Kids today would have no understanding of what they were looking at if they saw one. My scar finally disappeared in my 20s I think.
The smallpox vaccine is undoubtedly one of the most effective and significant vaccines in the history of humanity. Unfortunately even it doesn't last forever. If smallpox ever escapes one of the labs that still hold it - or if it is synthesized de novo from the digitally published genome by some demented party, we'll have to get another vaccination if we're around to see it.
This is the one single case of humanity eliminating a virus from the wild through vaccination. Smallpox vaccinations in various forms go back a long time. But the Jenner vaccine was the first to be widely deployed starting in the early 1800s. So, a really excellent vaccine was able to eliminate a virus in a mere 170 years give or take.
Those that implied (but generally never came out and directly said) that covid would be defeated through mandating widespread vaccination either did not know what they were talking about or were just not telling the truth.
Edited by Daniel Cooper, 20 August 2023 - 03:47 AM.