In 1980 the Sandinista government launched the massive Nicaraguan Literacy Campaign, and claimed the illiteracy rate fell from 50% to 13% in the span of five months. These figures are disputed, as many "unteachable" illiterates were omitted from the statistics, and many people declared literate were found to be unable to read or write a simple sentence. The UNESCO awarded Nicaragua the Nadezhda K. Krupskaya prize in recognition of its efforts. The FSLN also focused on improving the Nicaraguan health system, particularly through vaccination campaigns and the construction of public hospitals. These actions reduced child mortality by half, to 40 deaths per thousand. By 1982, the World Health Organization deemed Nicaragua a model for primary health care.