Madagascar 2005 Quotes

One was that, as live viruses, the attenuated Sabin poliovirus strains always possessed the potential to revert by mutation to virulence and neurotropism, leading to outbreaks of “vaccine-associated paralytic polio.” This possibility—that the vaccine itself would unleash epidemic disease—is not simply theoretical. Outbreaks of vaccine-associated polio occurred in the Philippines (2001), Madagascar (2002), China (2004), and Indonesia (2005).