In accordance with World Health Organization recommendations, applicants for Republic of China (Taiwan) visas must submit proof of having been administered the oral poliovirus vaccine (OPV) or the inactivated poliovirus vaccine (IPV) four weeks to one year before applying if they have resided in or visited countries at high risk for poliovirus transmission (namely Afghanistan, Malawi, Mozambique, Pakistan, Madagascar, and the Democratic Republic of the Congo) for four weeks or longer within the past year.