3.2.2  Storage, dosage, schedule and effectiveness of OPV

Store OPV between +2°C and +8°C; but it may be frozen for long-term storage.

Four doses are given, each of two drops. OPV should be given at birth, 6 weeks, 10 weeks and 14 weeks of age. The interval between all doses must be at least four weeks. The birth dose is known as OPV0; the subsequent doses are referred to as OPV1 (at 6 weeks), OPV2 (at 10 weeks), and OPV3 (at 14 weeks).

You should not give OPV0 (the birth dose) to an infant who is more than 14 days old. If this dose has not been given by 14 days, miss this dose and wait until the child is six weeks old, and then give OPV1. You should also give the first doses of the other routine EPI vaccines, including PCV10, at six weeks. The remaining doses should be given as scheduled at 10 and 14 weeks.

If a child spits out the vaccine drops, or vomits immediately after a dose of OPV, it is quite safe to repeat the dose. You should still give the scheduled dose even if a child has diarrhoea at the time; give OPV as usual, but administer an extra (fifth) dose at least four weeks after he or she has received the final dose in the schedule. Ninety-nine per cent of those who are vaccinated with four doses of OPV are protected from polio for life, but during campaigns children are often given additional boosters of OPV to ensure high herd immunity.