evidence: Composition, forms, route of administration - Inactivated virus vaccine, trivalent (poliovirus types 1, 2 and 3) [...] Remarks - Protection against poliomyelitis lasts for life after 4 doses. - In children who start routine vaccination late (after the age of 3 months), the dose of IPV is administered together with the 1st dose of bOPV, followed by 2 doses of bOPV alone administered 4 weeks apart.