The cause
of the polio virus This is a family event Enterovirus in the Picornaviridae and a 3 Serotype of Type 1, 2 and 3, each of which may be found to cause paralysis type 1 causes paralysis and attenuated outbreaks more often than the other sites. Once infected, there is a kind of permanent immunity occurs only for SUBTYPE it. SUBTYPE no immunity, so in theory it could infect up to 3 times.