In this Monday, April 23, 2013 photo pediatrician Fyodor Lapiy examines a child before administering him a combined vaccine against diphtheria, whopping cough and tetanus in Children's Hospital No. 1 in Kiev,Ukraine. Only about one-half of Ukraine s children are fully immunized against vaccine-preventable communicable diseases in line with local health regulations, compared to over 90 percent in Western Europe, according to UNICEF, the United Nations children s agency. Such a low immunization rate has already led to a major outbreak of measles and a risk of an outbreak of polio, a highly dangerous disease which may cause paralysis and which has been unseen in Ukraine for more than a decade, UNICEF and the World Health Organization said ahead of the current World Immunization week.