Figure 2.
Bacterial lysate improves antibody response against influenza H1N1 virus. (A) Immunoassays for IgG against H1 (p for comparison = 0.028), (B) avidity of IgG for H1 (p for comparison = 0.042), and (C) hemagglutinin-inhibition of H1N1 influenza virus (p for comparison = 0.03) in serum from BALB/c mice obtained 60 days after intranasal infection with 106 PFU influenza virus A (A/new Caledonia 120/99-like (H1N1)) in the presence or absence of lysate as described in Materials and Methods. (D) BALB/c mice were inoculated with H1N1 (104.5 pfu) either alone or with bacterial lysate, challenged 28 days later with H1N1 (106 pfu), and lung viral titers were assessed 4 days after challenge. (E) Percentage of body weight loss was determined on the same experimental group described in (D) at day 6 after challenge. All experiments were performed in duplicates using 6-10 mice/group.