Title Page
Contents
I. Introduction 6
II. Materials and Methods 9
1. Study Design 9
2. Viruses 9
3. Introduction of the reversed X-187 virus 10
4. Hemagglutination inhibition assays 10
5. Egg passages of the X-187 and reversed X-187 virus 11
6. Cell passages of the reversed X-187 virus 11
7. Sequence analysis 11
8. Statistical analysis 12
III. Results 13
1. Antigenicity of the X-187 (A/H3N2) vaccine virus 13
2. Mutation of the X-187 (A/H3N2) vaccine virus 18
3. Mutation of the reversed X-187 vaccine virus 20
IV. Discussion 23
V. Conclusion 26
REFERENCES 27
ABSTRACT 30
Table 1. Geometric mean HI titers and seroprotection rates (%) of the randomly selected 80 influenza vaccinees, of which homologous HI titers... 17
Figure 1. Distribution of HI antibody titers of 2011-12 influenza vaccinees against X-187 vaccine virus, vaccine prototype A/Victoria/210/2009 virus... 14
Figure 2. Geometric mean HI titers of 2011-12 influenza vaccinees against X-187 vaccine virus, vaccine prototype A/Victoria/210/2009 virus... 15
Figure 3. Seroprotection rates (%) of 2011-12 influenza vaccinees against X-187 vaccine virus, vaccine prototype A/Victoria/210/2009 virus and the... 16
Figure 4. Hemagglutinin amino acid sequences of 2011-12 egg-adapted A/Victoria/210/2009 X-187 high growth reassortant vaccine strain and... 19
Figure 5A. Hemagglutinin amino acid sequences of the reversed X-187 virus and sequentially subcultured viruses in eggs: Serine at residue 244... 21
Figure 5B. Hemagglutinin amino acid sequences of the reversed X-187 virus and sequentially subcultured viruses in cells: Serine at residue 244... 22