Comparison: Duration of illness, risk of treatment failure, for those with severe pneumonia: length of hospital stay. Number of non-injury clinic visits and hospitalizations during the intervention with Zinc and an in a 6 month period after enrolment. Growth assessed by anthropometry and thymus size assessed by ultrasonography. Explore the efficacy of zinc in etiology-sub groups including those defined by nutritional status, inflammation, fever, gender, breastfeeding status and viral etiology.