Belgium is the top country by immunization against DPT in the world. As of 2015, immunization against DPT in Belgium was 99 %. The top 5 countries also includes Antigua and Barbuda, Bhutan, Belarus, and Brunei Darussalam.
Child immunization measures the percentage of children ages 12-23 months who received 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.