TABLE 1.
Effect of amino acid changes in the HA of A/Vietnam/1203/04 (H5N1) virus on the antigenic specificity of escape mutants
| Escape mutant | HA amino acid changea
|
Reactivity with MAbb:
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| H3 numbering | H5 numbering | VN04-2 | VN04-8 | VN04-9 | VN04-10 | VN04-13 | VN04-15 | VN04-16 | 777/1 | |
| m2(1) | S126Y, I155T | S121Y, I151T | < | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| m2(4) | R166G | R162G | < | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| m8(9) | K144E | K140E | 0 | < | 0 | 0 | 0 | < | 0 | −2 |
| m9(5) | K156E | K152E | 0 | 0 | < | < | 0 | 0 | < | < |
| m9(6) | T160A, K193E | T156A, K189E | 0 | 0 | < | 0 | < | 0 | 0 | < |
| m10 | K156E | K152E | 0 | 0 | < | < | 0 | 0 | < | < |
| m13(13) | S145F | S141F | 0 | < | 0 | 0 | < | < | 0 | < |
| m13(16) | D187N, K193E | D183N, K189E | 0 | 0 | < | 0 | < | −1 | 0 | < |
| m15(17) | S145P | S141P | 0 | < | 0 | 0 | −2 | < | 0 | < |
| m15(20) | G143E | G139E | 0 | < | 0 | 0 | 0 | < | 0 | 0 |
| m16 | K156N | K152N | 0 | 0 | < | < | 0 | 0 | < | < |
| m777/1(2) | S145P | S141P | 0 | < | 0 | 0 | −2 | < | 0 | < |
| m777/1(4) | S145T | S141T | 0 | < | 0 | 0 | 0 | −2 | 0 | < |
a
Amino acid numbering is based on H3 HA and H5 HA (6).
b
Values are the differences in log2 units between the HI titers of MAbs in reactions with the wild-type VNH5N1-PR8/CDC-RG (H5N1) virus and with its escape mutants. 0, The HI titer of the MAb does not differ from the titer with the wild-type virus. <, The HI titer at least 32-fold (5 log2) less than the titer with the wild-type virus.