NIID released a small series of sequences at GISAID, including two from Japan. Both had G158E, the polymorphism found in two isolates from Germany, which were designated low reactors by the CDC and Mill Hill. A/YAMAGATA/721/2009 was collected Dec 8 and had a mixed signal at position G158E. The other was A/IWATE/1093/2009 and collected Oct 27.
The presence of G158E in both sequences from Japan raises concerns that low reactors are becoming more prevalent. In the two isolates from Germany, the only non-synonymous change is G158E. This change has also been found in two isolates with D225G, one in Italy and one in Russia. Mill Hill has also designated D225G as a low reactor. Moreover, the Yamagata isolate also has D225N, which like D225G has been linked to severe and fatal H1N1 cases.
via H1N1 G158E Low Reactors In Japan Raise Vaccine Concerns.