TABLE 2.

Geometric mean of neuraminidase inhibition reciprocal titers of homologous, contemporary, and human N2 antigens against a swine reference antisera panel^a

^aH9N2 swine antisera (n = 2 pigs per antigen) were tested against wild-type H3N2 or H1N2 influenza A viruses in the enzyme-linked lectin assay. The geometric means of the reciprocal 50% inhibition titers were extracted from merged antigenic cartography data, and homologous titers are bold and underlined. Boxes indicate titers from same lineage (i.e., N2-98 or N2-02). NT, not tested.