In this photo by Bullit Marquez, a health worker vaccinates a baby in the Philippines during a monthlong campaign to immunize 13 million children nationwide against measles, rubella and polio. The campaign has reached an estimated 30 percent of its target in the first two weeks. More than 16,700 measles cases have been confirmed in the Philippines this year. Health Secretary Enrique Ona said the outbreak is not an epidemic yet but they are immunizing children to prevent one. The Philippines is considered polio-free, but the World Health Organization has warned that global travel may spread the crippling disease into countries that had thought themselves free of the virus.