The primary outcome of the study is radiologically confirmed first or the only episode of pneumonia according to the WHO standard classification, i.e. [presence of dense or fluffy opacity that occupies a portion or whole of a lobe or the entire lung] or [presence of fluid in the lateral pleural space, between the lung and chest wall or both] 36. X-rays will be read by independent expert radiologists, blind to the child's allocation and clinical condition, and using a WHO Proforma Standardised Interpretation 36,37 of chest radiographs for the diagnosis of pneumonia in children.