Oral Polio Vaccine. It's actually both more effective and cheaper than the injected vaccine used today, as well as being attractive to children (well at least m

Oral Polio Vaccine. It's actually both more effective and cheaper than the injected vaccine used today, as well as being attractive to children (well at least me) because it's in the form of a weird fluid dripped onto a sugar code - looks like it might turn you into a superhero. The reason we don't use OPV in the rich industrial countries any more is that we don't have Polio here, so the improved efficacy and lower price aren't a worthwhile trade for the small but real risk of it reverting in some patients and producing an outbreak of Polio in the residual unvaccinated population.