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Seasonal Flu Sequence References

Datasets July 13, 2026

Curated GISAID EPI_SET genetic sequence references for seasonal influenza (H3N2, H1N1pdm09, B Victoria), including Complete and Contemporary per-segment datasets plus ferret antisera reagent references.

Genetic References

Genetic sequence references for seasonal influenza (H3N2, H1N1pdm09, B Victoria). Two categories of genetic reference datasets exist, “Complete” and “Contemporary”. “Complete” datasets have references across a longer term of evolutionary history of each seasonal influenza type. “Contemporary” datasets are limited to more recent genetic breakpoints for each seasonal influenza type.

These datasets are generated on a per-segment level. EPI_SET searches will return all samples from the set, but only the specific segment should be downloaded for sequences.

Complete

Subtype Data Window
H1N1pdm09 From the 2009 pandemic onwards
H3N2 From 2008 onwards
B Victoria From 2008 onwards

Datasets:

Subtype Segment EPI_SET DOI Sample Number
H3N2 HA EPI_SET_260713pc https://doi.org/10.55876/gis8.260713pc 1170
H3N2 MP EPI_SET_260713qr https://doi.org/10.55876/gis8.260713qr 1599
H3N2 NA EPI_SET_260713gc https://doi.org/10.55876/gis8.260713gc 1525
H3N2 NP EPI_SET_260713ey https://doi.org/10.55876/gis8.260713ey 1703
H3N2 NS EPI_SET_260713fq https://doi.org/10.55876/gis8.260713fq 474
H3N2 PA EPI_SET_260713df https://doi.org/10.55876/gis8.260713df 1642
H3N2 PB1 EPI_SET_260713hf https://doi.org/10.55876/gis8.260713hf 1284
H3N2 PB2 EPI_SET_260713gs https://doi.org/10.55876/gis8.260713gs 1418
H1N1pdm09 HA EPI_SET_260713us https://doi.org/10.55876/gis8.260713us 891
H1N1pdm09 MP EPI_SET_260713tw https://doi.org/10.55876/gis8.260713tw 963
H1N1pdm09 NA EPI_SET_260713zc https://doi.org/10.55876/gis8.260713zc 951
H1N1pdm09 NP EPI_SET_260713vz https://doi.org/10.55876/gis8.260713vz 739
H1N1pdm09 NS EPI_SET_260713dk https://doi.org/10.55876/gis8.260713dk 482
H1N1pdm09 PA EPI_SET_260713zm https://doi.org/10.55876/gis8.260713zm 926
H1N1pdm09 PB1 EPI_SET_260713rq https://doi.org/10.55876/gis8.260713rq 1137
H1N1pdm09 PB2 EPI_SET_260713on https://doi.org/10.55876/gis8.260713on 1220
B Victoria HA EPI_SET_260713yc https://doi.org/10.55876/gis8.260713yc 1039
B Victoria MP EPI_SET_260713yo https://doi.org/10.55876/gis8.260713yo 882
B Victoria NA EPI_SET_260713sn https://doi.org/10.55876/gis8.260713sn 1413
B Victoria NP EPI_SET_260713sk https://doi.org/10.55876/gis8.260713sk 1178
B Victoria NS EPI_SET_260713rw https://doi.org/10.55876/gis8.260713rw 1549
B Victoria PA EPI_SET_260713vf https://doi.org/10.55876/gis8.260713vf 1045
B Victoria PB1 EPI_SET_260713pv https://doi.org/10.55876/gis8.260713pv 889
B Victoria PB2 EPI_SET_260713cx https://doi.org/10.55876/gis8.260713cx 998

Contemporary

Subtype Data Window
H1N1pdm09 From the origin of 6B.1A.5a (~2018, Subclade A) onwards
H3N2 From the origin of 3C.2a1b.2 (mid-2017, Subclade E) onwards
B Victoria From the origin of V1A.3 (~2017, Subclade A.3) onwards

Datasets:

Subtype Segment EPI_SET DOI Sample Number
H3N2 HA EPI_SET_260713co https://doi.org/10.55876/gis8.260713co 718
H3N2 MP EPI_SET_260713wg https://doi.org/10.55876/gis8.260713wg 1329
H3N2 NA EPI_SET_260713hw https://doi.org/10.55876/gis8.260713hw 1092
H3N2 NP EPI_SET_260713tq https://doi.org/10.55876/gis8.260713tq 1358
H3N2 NS EPI_SET_260713ms https://doi.org/10.55876/gis8.260713ms 413
H3N2 PA EPI_SET_260713fh https://doi.org/10.55876/gis8.260713fh 1352
H3N2 PB1 EPI_SET_260713sq https://doi.org/10.55876/gis8.260713sq 917
H3N2 PB2 EPI_SET_260713bz https://doi.org/10.55876/gis8.260713bz 1088
H1N1pdm09 HA EPI_SET_260713bg https://doi.org/10.55876/gis8.260713bg 459
H1N1pdm09 MP EPI_SET_260713wd https://doi.org/10.55876/gis8.260713wd 767
H1N1pdm09 NA EPI_SET_260713td https://doi.org/10.55876/gis8.260713td 545
H1N1pdm09 NP EPI_SET_260713sr https://doi.org/10.55876/gis8.260713sr 522
H1N1pdm09 NS EPI_SET_260713vw https://doi.org/10.55876/gis8.260713vw 320
H1N1pdm09 PA EPI_SET_260713dg https://doi.org/10.55876/gis8.260713dg 734
H1N1pdm09 PB1 EPI_SET_260713og https://doi.org/10.55876/gis8.260713og 947
H1N1pdm09 PB2 EPI_SET_260713tp https://doi.org/10.55876/gis8.260713tp 863
B Victoria HA EPI_SET_260713ym https://doi.org/10.55876/gis8.260713ym 701
B Victoria MP EPI_SET_260713oq https://doi.org/10.55876/gis8.260713oq 668
B Victoria NA EPI_SET_260713nk https://doi.org/10.55876/gis8.260713nk 906
B Victoria NP EPI_SET_260713bu https://doi.org/10.55876/gis8.260713bu 955
B Victoria NS EPI_SET_260713cy https://doi.org/10.55876/gis8.260713cy 1431
B Victoria PA EPI_SET_260713go https://doi.org/10.55876/gis8.260713go 917
B Victoria PB1 EPI_SET_260713xs https://doi.org/10.55876/gis8.260713xs 782
B Victoria PB2 EPI_SET_260713kn https://doi.org/10.55876/gis8.260713kn 880

Reagent References

Reagent references are samples representing current CDC ferret antisera used in phenotypic tests.

Subtype EPI_SET DOI Sample Number
H3N2 EPI_SET_260714ep https://doi.org/10.55876/gis8.260714ep 144
H1N1pdm09 EPI_SET_260714xo https://doi.org/10.55876/gis8.260714xo 107
B Victoria EPI_SET_260714as https://doi.org/10.55876/gis8.260714as 111

Notes on Datasets

  • Datasets will be updated quarterly
  • These current datasets were generated on 2026-07-13
Tags: genetic-references sequences gisaid epi-set h3n2 h1n1pdm09 b-victoria