 As a consequence, a vaccinated individual is protected from contracting polio, but their intestinal mucosa can still be infected and serve as a reservoir for the excretion of live virus.For this reason, IPV is ineffective at halting ongoing outbreaks of WPV or cVDPV, but it has become the vaccine for choice for industrialized, polio-free countries.While IPV does not itself induce mucosal immunity, it has been shown to boost the mucosal immunity from OPV, and WHO now favors a combined protocol.