5W0D:
reference: Memory B Cells that Cross-React with Group 1 and Group 2 Influenza A Viruses Are Abundant in Adult Human Repertoires., McCarthy KR, Watanabe A, Kuraoka M, Do KT, McGee CE, Sempowski GD, Kepler TB, Schmidt AG, Kelsoe G, Harrison SC, Immunity. 2018 Jan 16;48(1):174-184.e9. doi: 10.1016/j.immuni.2017.12.009. PMID: 29343437

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