Influence extent Judgment method Judgment method Judgment method Judgment method
r value of HI titer Antigen map of HI titer r value of microneutralization titer Antigen map of microneutralization titer
Significant antigenic differences A168N, T198A, D201G A168N, D201G R164Q, D201G, A168N, D201A A168N, D201G, T198A, I171T
Small antigenic differences D201A, R164Q / I171T, R200T /
Antigenically similar I171T, R200T T198A, I171T, R200T, D201A, R164Q T198A R200T, R164Q, D201A, R200T