Table 2. Neutralizing antibody responses to the vaccine strain (A/Vietnam) and the challenge strain (A/Indonesia) 42 days after first vaccination, i.e 21 days after second vaccination.
| Vaccination regimen | Anti-A/Vietnam neutralizing titers | Anti-A/Indonesia neutralizing titers | ||
| Day 21(Post II)a | Respondersb | Day 21 (Post II)a | Respondersb | |
| GMT (95% CI) | GMT (95% CI) | |||
| Adjuvant alone | <28 | 0/6 | <28 | 0/6 |
| Unadjuvanted H5N1 (15 µg) | <28 | 0/6 | <28 | 0/6 |
| Adjuvanted H5N1 (1.7 µg) | 83 (19–371) | 4/6 | 36 (15–83) | 4/6 |
| Adjuvanted H5N1 (3.8 µg) | 113 (24–521) | 4/6 | 43 (16–116) | 4/6 |
| Adjuvanted H5N1 (7.5 µg)a | 104 (18–602) | 4/5 | 35 (12–107) | 3/5 |
| Adjuvanted H5N1 (15 µg) | 83 (29–234) | 5/6 | 26 (12–55) | 3/6 |
a
Neutralizing antibody GMT were <28 before immunization (Day 0) and after first vaccination (Day 21 Post I).
b
A responder is defined by neutralizing titers ≥ 28.