Anti vaxxers have existed for a very long time (pre Facebook) and their conspiracies are often fuelled by facts like the CIA using fake vaccination campaigns under Obama or White governments doing trials (or not and lying) on blacks etc.... So the moral of the story to them is that non-whites should distrust whites (white countries and governments) bearing “gifts” especially when it comes to medicine and vaccinations.
https://en.wikipedia.org/wiki/Tuskegee_Syphilis_Study
https://www.scientificamerican.com/article/how-cia-fake-vacc...
https://www.nationalgeographic.com/science/article/150227-po...