It's getting more and more difficult to justify the decision not to vaccinate a child. In recognition of World Immunization Week from April 24-30, 2015, UNICEF created an infographic to point out how crucial vaccinations are in preventing diseases like polio, tetanus and measles. Not only do they save lives, they save the world economy lots of money. Every year, vaccines prevent about 2.5 million deaths, according to the organization, and -- if vaccines were given to every child in the 72 poorest countries -- roughly $6.2 billion would be saved throughout the next decade in treatment costs. But a wide range of factors still prevent far too many children from accessing immunizations, according to Caryl Stern, president and CEO of the U.S.