Very good question and a very good answers in this article! I'll add one more reason not explored by the authors: antibodies don't "leak" in the environment, in contrast to the antibiotics which are everywhere. For example, if I'm vaccinated against S. pneumoniae (one of the bacteria that can cause pneumonia), the bacteria have to get inside my body to gain exposure to my vaccine-induced antibodies. This makes the em…
Well that’s just some hand wavy pseudoscience right there.
Regarding the OPV Polio Vaccine, from the Global Polio Eradication Project site - “For several weeks after vaccination the vaccine virus replicates in the intestine, is excreted and can be spread to others in close contact”
Source: http://polioeradication.org/polio-today/polio-prevention/the...