Amino acid sequences from the peptides used for immunization compared to the homologue sequence of the HA receptor recognition domain of the challenging strain (pH1N1) and the HA purified proteins used for the serologic tests.

In bold type, the amionacids differences between sequences are represented. Differences between the pH1N1 virus and the H1-peptide (NF-34) in homologous positions within the HA receptor recognition domain are marked. Aminoacid differences in the two H5-HK derived peptides (LE-35.1/2) are also represented.