This page has a list of countries by Immunization, DPT (% of children ages 12-23 months), according to officially-recognized international sources compiled by the World Bank. Child immunization, DPT, measures the percentage of children ages 12-23 months who received DPT vaccinations before 12 months or at any time before the survey. A child is considered adequately immunized against diphtheria, pertussis (or whooping cough), and tetanus (DPT) after receiving three doses of vaccine.