Differences in HA1 sequence between Wisconsin/05 and Uruguay/07 PR8 reassortant vaccine strains.

1Changes in parentheses are not present in other isolates from the same season, so may not be antigenically significant. The percent variation analyses were done using the Influenza Research Database using the “Analyze Sequence Variation” [52].
2All Wisconsin/67/05 sequences have D but 99.7% of 2005/6 isolates have N.
3Q in PR8 reassortants, not isolates from primary chick kidney cells or egg passages.
4V in PR8 ressortants and some other Wisc/67/05 entries; 98.8% of 2005–6 isolates have G.
5I in all Wisc/67/05 entries but 97% of 2005/6 isolates have V.
6P in egg-passaged viruses but not many others.
7G only in reassortant X-175.