This study reviews 54 Kenyan children with measles of varying severity. Children with severe measles and extensive staining of the skin had prolonged excretion of giant cells (presumably virus-containing) from their nasopharyngeal mucosa, ranging from 8 to 28 days after start of rash. Children with mild measles excreted giant cells for three days or less, conforming to the North American pattern of illness. Prolonged excretion of giant cells suggests an impaired cellular immune response in these children, which may be a function of their seriously impaired nutrition.