Eh, the oral polio vaccine is old, cheap, and kind of predates the rise of modern big pharma. Disease eradication is just a hard problem in general. The only hu

Eh, the oral polio vaccine is old, cheap, and kind of predates the rise of modern big pharma. Disease eradication is just a hard problem in general. The only human infectious disease that's been eradicated - smallpox - was a particularly easy target for various unique reasons, including the existence of a live vaccine that was incredible effective despite being so wildly different from the actual disease-causing virus that it couldn't easily cause serious disease in humans itself.