after a local epidemic of a/ussr influenza , immunologic parameters related to influenza a/ussr/90/77 ( h1n1 ) virus were studied in four age groups : elderly persons ( greater than or equal to 64 years ) , healthy adults ( 20-44 years ) , children ( six to 13 years ) , and neonates ( who served as controls ) .
C0008059
children
C0021289
neonates