High-Titre Neutralizing Antibodies to H1N1 Influenza Virus after Mouse Immunization with Yeast Expressed H1 Antigen: A Promising Influenza Vaccine Candidate

Figure 7

Humoural response in mice after immunization with the H1 antigen. Sera samples of mice immunized with 1, 5, and 25 μg of H1 adjuvanted with Alhydrogel were pooled and the immune responses were measured two weeks after immunization (a), booster (b), and second booster (c) by indirect ELISA (nonlinear fitting plots: bars represent standard deviation; column plots: bars represent 95% confidence level) and two weeks after second booster by HI test (d). Data for individuals (raw data, ♦), mean (○), and the medians (□) are shown for each group. During the second immunization experiment, two doses of 1, 5, and 25 μg of H1 adjuvanted with Sigma Adjuvant System were tested. Sera samples of mice immunized twice were measured two weeks after the first antigen injection (e) and booster (f) by indirect ELISA (bars represent 95% confidence level). Two weeks after booster, the HI test was performed with homologous H1N1pdm09 virus (f). Data for individuals (raw data, ♦), mean (○), and the medians (□) are shown for each group.

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