An estimated 4.3 million children were vaccinated against polio and given vitamin A supplements during the first round of the National Immunization Days (NIDs) in Afghanistan. In the remote areas, 20,000 health workers and volunteers were trained and deployed to reach children for vaccination. Moreover, the WHO helped in the distribution of supplies and sent supervisors into three villages of the remote district of Badakshan. A strong-mounted, well-coordinated social mobilization campaign through the local radio was made possible by mosques, the BBC, Voice of America, and print media in Afghanistan and Pakistan. NIDs are jointly conducted by the WHO, the UN Children's Fund, the Ministry of Public Health, and nongovernmental organizations. Mass immunization campaigns and NIDs have been conducted in Afghanistan since 1994.