This is something that my history teacher told me but it seemed strange to me so I tried checking on google but I could only get things related to the Apocalypse Now movie, because apparently this is shown in the movie. Did it actually happen? And, would it actually make the vaccine useless? Because I would think that you could get a vaccine on different parts of the body, not only on your arms and once it is injected, the effect can not be reversed, am I wrong?