Immunization: This report presents WHO and UNICEF estimates of national immunization coverage. Since 2000, the estimates are updated once annually in July, following a consultation process wherein countries are provided draft reports for review and comment. As the system incorporates new empirical data, each annual revision supersedes prior data releases, and coverage levels from earlier revisions are not comparable. A more detailed explanation of the process can be found at . Regional averages for the reported antigens are computed as follows: • For BCG, regional averages include only those countries where BCG is included in the national routine immunization schedule. • For DPT, polio, measles, HepB, Hib, PCV and rotavirus vaccines, regional averages include all countries, as these vaccines are universally recommended by WHO. • For protection at birth (PAB) from tetanus, regional averages include only the countries where maternal and neonatal tetanus is endemic. Treatment indicators: Until recently, ‘Proportion of children under 5 with fever who are treated with appropriate antimalarial drugs’ was the standard indicator for monitoring coverage of antimalarial treatment in children under 5. However, it has become increasingly challenging to track trends in this indicator, following a 2010 WHO recommendation that advised universal use of diagnostic testing to confirm malaria infection before applying any treatment. To implement this recommendation, many countries are scaling up the use of diagnostic testing to focus treatment on only those diagnosed with malaria. Given that increasingly higher number of fever cases are not malaria, low levels of antimalarial treatment in febrile children may indicate that antimalarials are being provided only to confirmed cases. For more information on this issue, see the 2013 edition of the Household Survey Indicators for Malaria Control. Given these methodological issues, this indicator is no longer tracked for coverage monitoring and has now been replaced with ‘Care seeking for fever’ in this publication. The indicator ‘Antibiotic treatment for children with symptoms of pneumonia’ has been dropped from this table as well. This indicator refers to antibiotic treatment among children whose caretakers report symptoms that are related to acute respiratory infection. However, these children have not been medically diagnosed with pneumonia, thus leading to substantial validity issues. Studies have shown that high percentage of children with symptoms of acute respiratory infection do not have true pneumonia. Therefore, this indicator is no longer recommended for coverage monitoring. TABLE 4. HIV/AIDS In 2015, the Joint United Nations Programme on HIV/AIDS (UNAIDS) released new global, regional and country-level HIV and AIDS estimates for 2014 that reflect key changes in WHO HIV treatment guidelines for adults and children and for the prevention of mother-to-child transmission of HIV, in addition to improvements in assumptions of the probability of HIV transmission from mother to child and net survival rates for infected children. Furthermore, there are also more reliable data available from population-based surveys, expanded national sentinel surveillance systems and programme service statistics in a number of countries. Based on the refined methodology, UNAIDS has retrospectively generated new estimates of HIV prevalence, the number of people living with HIV and those needing treatment, AIDS-related deaths, new HIV infections and the number of children whose parents have died due to all causes including AIDS for past years. 114 THE STATE OF THE WORLD’S CHILDREN 2016