Serum samples and 50% NAI values. Serum samples taken from CEIRS study.

Serum genotype, 50% NAI (NAI50) titer and fold difference shown. Twenty convalescent serum samples taken approximately 28 days after confirmed H3N2 infection used. Ten from 245 NA Gly+ infected patients, 10 from individuals infected with a 245 NA Gly- virus. NAI50 values are the highest titer that resulted in at least 50% inhibition of enzyme activity in ELLA assay using H6N2 viruses expressing either 245 NA Gly+ or 245 NA Gly- protein. Data shown from one biological replicate. Each NAI assay was conducted in duplicate and averaged to determine titer.