How much of a dose of oral polio vaccine can be spit out before the dose needs to be repeated?
There is no definite rule. However, if, in the judgement of the person administering the vaccine, a substantial amount of vaccine is spit out, regurgitated, or vomited shortly after administration (i.e., within 5-10 minutes), another dose can be administered at the same visit. If this repeat dose is not retained, neither dose should be counted, and the vaccine should be re-administered at the next visit.
