Table 1. Antibodies to A(H1N1)pdm09 in seals and sea lions in California, USA, 2009–2012.
| % HI positive | ||||
|---|---|---|---|---|
| Northern elephant seals | Harbor seals3 | California sea lions4 | Range HI titers | |
| 20091 | 5 (2/37) | 8 (3/40) | 0 (0/80) | <10 to 160 |
| 20101 | 30 (11/37) | 2 (1/50) | 7 (4/55) | <10 to 640 |
| 20111 | 48 (29/60) | 0 (0/50) | 6 (3/48) | <10 to 640 |
| 2012 | ||||
| Adult females2 | 54 (19/35) | - | - | <10 to 160 |
| Pups 1st sample2 | 63 (22/35) | - | - | <10 to 320 |
| Pups 2nd sample2 | 75 (15/20) | - | - | <10 to 320 |
Sera tested by HI at dilutions of 1/10, 1/20, 1/40, 1/80, 1/160, 1/320, 1/640. Titers ≥40 were considered positive.
1
Free-ranging and stranded adults and juveniles in northern and southern California.
2
Free-ranging adults and pups at the Southern California Channel Islands.
3
Seropositive harbor seals were stranded weaned pups from northern and central California with HI titers of 40 to 160.
4
Seropositive California sea lions were stranded and free-ranging subadults and adults from northern and southern California with HI titers of 40 to 80.