Figure 5. Vaccine efficacy by dose, conjugation time, or addition of adjuvants. Mice (n = 5) were vaccinated with indicated amounts (15 or 60 µg) of the TMV-HA conjugate protein conjugated for 30’ or 60’ (minutes) with or without adjuvant Alum (Alum) or with oil-in-water squalene adjuvant (Sq; AddaVax). ELISA analysis of anti-HA IgG titers in sera collected at 14 or 28 d after the first vaccination (A pV1) or after the second vaccine (B pV2) given at day 30. Asterisks in A represent IgG titers significantly greater (P < 0.05) than induced by HA 60 vaccination. Titers were measured against a known quantity of anti-HA standard (Sino Biological Inc.). Numbers above the bars are the HAI presented as a geometric mean titer.