TABLE 2.
Antigenic characterization of avian H2N2 influenza viruses by HI assay
| Categoryb | Animal origin | H2N2 isolate | Postinfection ferret serum titer raised againsta: |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Avian viruses |
Human viruses |
Swine virus Sw/MO/06 | |||||||
| Mal/MT/61 | Ck/Jena/84 | Dk/Shan/00c | Ck/PA/04 | Sing/57d | Neth/68 | ||||
| Eurasian | Wild | Mal/MT/61 | 320 | 160 | 640 | < | 320 | 20 | 160 |
| Wild | Mal/Pot177/83 (H2N1) | 80 | 160 | 640 | < | 80 | 20 | 80 | |
| Wild | Mal/Pot179/83 | 80 | 160 | 640 | < | 80 | 20 | 80 | |
| Domestic | Dk/HK273/78 | 160 | 320 | 640 | < | 80 | 40 | 160 | |
| Domestic | Dk/HK319/79 | 160 | 160 | 640 | 20 | 40 | 20 | 80 | |
| Domestic | Ck/Jena/83 | 320 | 320 | 640 | 20 | < | 40 | 80 | |
| Domestic | Ck/Jena/84 | 160 | 640 | 640 | 20 | < | 20 | 160 | |
| North American | Wild | Bwt/Alb/78 | 40 | 160 | 640 | < | 80 | < | 160 |
| Wild | Mal/NY/78 | 80 | 160 | 640 | < | 80 | < | 80 | |
| Wild | Mal/MN/98 | 80 | 20 | 640 | 20 | < | < | 320 | |
| Wild | Mal/MN/00 | 40 | 40 | < | < | < | < | 40 | |
| Wild | Mal/MN/08 | < | 20 | 20 | < | < | < | 40 | |
| Domestic | Ck/CT/90 | 80 | 80 | 640 | < | 80 | < | 160 | |
| Domestic | Ck/PA/91 | 80 | 80 | 640 | < | 40 | < | 40 | |
| Domestic | Ck/NY/91 | 40 | 80 | 640 | < | < | < | 40 | |
| Domestic | Dk/NJ/95 | 40 | 80 | 640 | < | < | < | 40 | |
| Domestic | GF/NY/95 | 40 | 160 | 640 | < | 40 | < | 80 | |
| Domestic | Ck/NY/95 | 80 | 80 | 640 | < | 40 | < | 80 | |
| Domestic | Ck/NJ/95 | 40 | 40 | 320 | < | 40 | < | 40 | |
| Domestic | Ck/NY/04 | 80 | 160 | 640 | 80 | 40 | < | 160 | |
| Domestic | Ck/PA/04 | 80 | 160 | 640 | 160 | < | 20 | 80 | |
| Control | Human | A/Singapore/1/57 | ND | ND | ND | ND | 320 | ND | ND |
| Human | A/Netherlands/65/68 | 160 | ND | ND | 80 | ND | 320 | ND | |
| Wild | A/WildDuck/Shantou/992/00 (H2N8) | ND | ND | 1,280 | < | ND | ND | ND | |
| Swine | Sw/MO/06 (H2N3) | 160 | 40 | 640 | ND | 40 | 20 | 320 | |
a
HI titers shown are the reciprocal of the highest doubling dilution that inhibited 4 hemagglutinating units of virus using horse red blood cells. “<” represents a titer below the cutoff of 1:20 serum dilution. ND, not determined; boldface, homologous virus control.
b
“Category” indicates geographic region or a nonavian isolate.
c
This serum was produced in chickens.
d
This serum was used with chicken red blood cells.