Table 2.
Hemagglutinin inhibition cross-reactivity between swine sera and H3N2 virus antigen combinations
| Antiserum | HI cross-reactivity for virus antigena: |
||||
|---|---|---|---|---|---|
| Sw/TX/98b (C1, 1998) | Sw/IL/09 (C4, 2009) | Sw/PAc (C4, 2010) | Sw/ILd (C4, 2011) | A/INe (C4, 2011) | |
| Sw/TX/98 | 2,560 | 160 | 160 | 40 | 80 |
| Sw/IL/09 | 30 | 320 | 120 | 100 | 15 |
| Sw/PA | 0 | 120 | 480 | 960 | 320 |
| Sw/IL | 0 | 20 | 240 | 960 | 60 |
| A/IN | 5 | 320 | 1280 | 960 | 1,280 |
The isolates used for swine antiserum production are identified in the far left column, with the geometric mean reciprocal titer of two serum samples per isolate given in each row. Virus isolates used as test antigens are identified in the top row. The hemagglutinin gene cluster (C) and year the virus was isolated are indicated in parentheses in the subheadings. Homologous serum/antigen combinations are shaded gray. HI, hemagglutinin inhibition.
Result from one reference serum sample.
Swine H3N2 virus with triple-reassortant internal gene (TRIG) cassette, H3N2-TRIG.
Reassortant H3N2 virus with TRIG-HA, -NA, and -PB2 and pandemic M, NP, NS, PA, and PB1 gene combinations (rH3N2p).
A(H3N2)v virus with pandemic matrix (pM) isolated from a human case.