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Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza at Center for Influenza Virus Research, National Institute of Infectious Diseases, Tokyo, Japan Takato Odagiri, Ph.D .
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Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Dec 13, 2015

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Page 1: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Update on InfluenzaVirus Surveillance Findings in 2008/09

Season in Northern Hemisphere

Who Collaborating Center for Reference and Research on Influenza at Center for Influenza Virus Research, National Institute of Infectious Diseases,

Tokyo, Japan

Takato Odagiri, Ph.D.

Page 2: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Weekly report of virus isolation/detection in 2008-09 season

By NIID

By CDC

Pandemic A/H1N1 viruses

3584(32%)

2071(19%)

2475(22%)

2949(27%)

H1N1

H1N1pdm

H3N2

BAs of 11 Aug

248(11%)

201 (9%)

625(28%)

1186(52%)

H1N1

H1N1pdm

H3N2

B

As of week 30

Page 3: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

A(H1N1) viruses September 2008-January 2009

Page 4: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

H1N1, Sept 2008 – Jan 2009

Page 5: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

H1N1 antigenic analysis

By NIID

Page 6: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

H1N1 antigenic analysis

By CDC

Page 7: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Summary of antigenic analysis of A/H1N1 in four WHO CCs

A/Br/59/07-like low-reactors (≥ 8-f)

• CDC (Oct-) 179 [100%] 0 [0%]• NIID (Oct-) 72 [95%] 4 [5%]• NIMR (Oct-) 62 [87%] 9 [13%]• VIDRL (Oct-) 119 [97.5%] 3 [2.5%]• Total 432 [96%] 16 [4%]

Page 8: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.
Page 9: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.
Page 10: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

March-July 2009

Page 11: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By CDC

Page 12: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By NIMR

Page 13: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Antigenic characterization of AH1N1 viruses isolated after March

By NIID

By CDC

Page 14: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.
Page 15: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By CDC

Number of oseltamivir resistance viruses isolated in Japan

(Oct 2008-May 2009)

By NIID

Page 16: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

H1N1 viruses - SummaryOct 2008-Feb 2009• Influenza A(H1N1) viruses predominated in many Asian and North

American countries• The majority of viruses were antigenically closely related to

A/Brisbane/59/2007 by HI analysis• Phylogenetically the majority of H1N1 viruses grouped into the

A/Brisbane/59/2007 clade (2B) based on their HA gene. • Recent 2B viruses share H275Y indicative of resistance to

oseltamivir. They were antigenically similar to osel-sensitive viruses.• Recent viruses from China fall within the A/Hong Kong/2652/2006

clade (2C) and these viruses were similar antigenically to clade 2B viruses. Clade 2C viruses are sensitive to oseltamivir and resistant to amantadine/rimantadine

Mar - July 2009• The features of viruses were similar to those observed earlier in

2009.• Majority of recent A(H1N1) viruses were antigenically closely related

to A/Brisbane/59/2007 and formed clade 2B sharing H275Y.• In the few clade 2C viruses, dual resistance to oseltamivir and

amantadine/rimantadine were detected.

Page 17: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

A(H3N2) viruses September 2008-January 2009

Page 18: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

H3N2, Sept 2008 – Jan 2009

Page 19: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By NIID

Page 20: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Table 4B. Antigenic analyses of influenza A H3N2 viruses - Guinea Pig RBCs (05/02/2009)

Viruses Collection A/Wis A/Trieste A/Wis A/Bris A/Uru A/Fin A/JHB A/Eng A/BrisDate 67/05 25c/07 3/07 10/07 716/07 9/08 15/08 394/08 24/08

F18/08 F5/07 F15/07 F29/08 F26/08 F12/08 F22/08 F32/08 F3/09

REFERENCE VIRUSES

A/Wisconsin/67/2005 31/08/2005 SpfCk3E3 \3 1280 1280 640 1280 2560 640 640 80 1280A/Trieste/25c/2007 Jan-07 MDCKx \2 80 160 160 320 160 80 160 160 160A/Wisconsin/3/2007 21/01/2007 Ex \2 5120 5120 2560 5120 5120 2560 2560 640 5120A/Brisbane/10/2007 06/02/2007 E2 \3 1280 2560 640 1280 2560 1280 1280 320 2560A/Uruguay/716/2007 21/06/2007 spfck1, E3 \2 1280 2560 640 1280 2560 2560 1280 320 1280A/Finland/9/2008 07/01/2008 MDCK2 \1 160 160 320 320 320 320 320 320 320A/Johannesburg/15/2008 25/06/2008 MDCKx \2 160 320 320 320 320 320 320 320 640A/England/394/2008 22/09/2008 MDCK2 \7 160 320 320 320 640 160 320 640 320A/Brisbane/24/2008 23/06/2008 E5 \1 2560 2560 2560 5120 5120 2560 2560 320 5120

TEST VIRUSES

A/Singapore/N474/2008 21/05/2008 Cx \1 1280 2560 1280 2560 5120 1280 2560 640 2560A/Singapore/N486/2008 21/05/2008 Cx \1 640 1280 320 1280 1280 640 640 320 640A/Singapore/N510/2008 04/06/2008 Cx \2 1280 2560 1280 2560 5120 2560 2560 640 1280A/Singapore/N593/2008 15/09/2008 Cx \1 1280 2560 640 1280 2560 1280 1280 640 2560A/Sweden/3/08 15/10/2008 MDCK2 \1 1280 1280 640 1280 1280 1280 1280 320 640A/England/694/2008 05/12/2008 SIAT P1 \1 1280 1280 640 1280 2560 640 1280 640 640A/England/687/2008 30/12/2008 MDCK P1 \2 640 1280 320 1280 2560 1280 1280 320 640A/Switzerland/1370948/2008 12/12/2008 MDCK2 \2 640 640 320 640 1280 320 320 160 320A/Seoul/4436/2008 05/12/2008 MDCK-P2 \1 640 640 320 640 1280 640 640 320 640A/Slovenia/60/2009 06/01/2009 MDCKx \1 640 640 320 640 1280 640 640 160 640A/Slovenia/51/2009 05/01/2009 MDCKx \1 160 80 160 160 320 160 160 160 160A/Baden-Württemburg/199/2008 15/12/2008 C4 \2 320 320 160 320 640 160 320 160 320A/Parma/17/09 12/01/2009 I MDCK \1 80 80 160 160 160 80 80 160 160A/Singapore/N565/2008 12/08/2008 Cx \2 1280 1280 320 1280 1280 640 1280 320 640A/Switzerland/1409256/2008 29/12/2008 cs \2 1280 1280 320 1280 1280 640 640 160 640A/Switzerland/1409281/2008 31/12/2008 cs \2 640 1280 320 640 1280 320 640 160 640A/Leon/5/2009 13/01/2009 MDCK1 \1 1280 2560 640 1280 2560 1280 2560 640 640A/Belgium/G211/2009 30/12/2008 MDCK1 \1 1280 2560 640 1280 2560 1280 1280 640 640A/Belgium/G228/2009 30/12/2008 MDCK1 \1 1280 1280 320 1280 1280 640 1280 320 640A/Belgium/G278/2009 08/01/2009 MDCK1 \1 1280 2560 640 1280 2560 1280 1280 640 640A/Belgium/G298/2009 12/01/2009 MDCK1 \1 1280 2560 640 1280 2560 1280 2560 640 640

1. < = <40 Vaccine strains

Passage History

Haemagglutination inhibition titre1

Post infection ferret sera

By NIMR

Page 21: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Table 5B. Antigenic analysis of influenza A H3N2 viruses (Neutralisation)

Viruses Collection A/Well A/Bris A/Uru A/Eng A/BrisDate 1/04 10/07 716/07 394/08 24/08

F13/04 F18/07 F3/07 F32/08 F3/09

REFERENCE VIRUSES

A/Wellington/1/2004 26/01/2004 E3 \1 1280 320 320 320 320A/Brisbane/10/2007 06/02/2007 E2 \3 320 2560 5120 320 2560A/Uruguay/716/2007 21/06/2007 spfck1, E3 \1 320 1280 2560 160 1280A/England/394/2008 22/09/2008 TC P2 \1 80 2560 2560 2560 1280A/Brisbane/24/08 23/06/2008 E5 160 1280 2560 320 2560

TEST VIRUSES

A/Paris/130/2008 20/10/2008 C2 \1 160 640 1280 320 1280A/Egypt/59/2008 16/11/2008 C1 \1 160 1280 1280 320 1280A/Toulouse/1317/2008 14/11/2008 P3MDCK \1 160 1280 2560 640 2560A/Norway/2308/2008 15/12/2008 MDCK1 \1 320 2560 2560 640 2560A/Denmark/191/2008 13/11/2008 MDCK3 \1 160 1280 2560 320 2560A/Sweden/6/2008 08/12/2008 MDCK2 \1 160 1280 1280 320 1280A/Paris/458/2008 1/12/2008 C1 \1 320 2560 5120 640 5120A/HongKong/3197/2008 26/11/2008 MDCK2 \1 160 1280 1280 320 1280A/England/669/2008 30/12/2008 MDCK P1 \1 80 1280 1280 320 1280A/Norway/1/2009 30/12/2008 MDCK1 \1 160 640 1280 320 1280

1 Based on 50% plaque reduction compared to serum negative controls2 RDE treatedAgglutinate guinea pig RBCs only

Vaccine strains

Passage History

Neutralisation titre1

Post-infection ferret sera2

By NIMR

Page 22: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

A/Brisbane/10/07-like low-reactors (≥ 8-f)

• CDC (Oct-) 45 [90%] 5 [10%]

• NIID (Oct-) 32 [56%] 25 [44%]

• NIMR (Oct-) 160 [90%] 18 [10%]*

• VIDRL (Oct-) 145 [93%] 11 [ 7%]

• Total 382 [87%] 59 [13%]

H3 low reactors in HI assays in WHOCCs

*0% by virus neutralization

Page 23: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Vaccine virus

Page 24: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

March-July 2009

Page 25: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By NIMR

Page 26: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By NIID

Page 27: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.
Page 28: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Vaccine virus

Page 29: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By Cambridge Univ.

Page 30: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

H3N2 viruses - Summary Oct 2008-Feb 2009• H3N2 viruses co-circulated with H1N1 and B viruses in many countries• Majority were antigenically similar to A/Brisbane/10/07 and

A/Uruguay/716/07 by HI tests with turkey RBCs or guinea pig RBCs.• The ‘low reactors’ were antigenically indistinguishable from vaccine

viruses by Neutralization tests. • HA and NA sequences fairly homogeneous and fell within the

A/Brisbane/10/07 clade • M2 sequences possessed S31N mutation, indicative of amantadine

resistance• Sensitive to oseltamivir and zanamivirMar - July 2009• Majority were antigenically similar to vaccine viruses.• An increasing number of H3N2 isolates have been shown to be

antigenically distinct from vaccine viruses and related to A/Hawaii/7/09, A/HK/1985/09 and A/Perth/16/09.

• The majority of HA sequences of those viruses formed a separate clade characterized by aa subsitutions E62K, N144K, K158N and N18K.

• They retained resistance to amantadine/rimantadine and were sensitive to oseltamivir and zanamivir.

Page 31: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

B viruses September 2008-January 2009

Page 32: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

B, Sept 2008 – Jan 2009

Page 33: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Numbers of 2 lineages of B viruses detected in GISN since week 40

2008

0

5

10

15

20

25

30

35

40

45

40 41 42 43 44 45 46 47 48 49 50 51 52 1 2 3 4

week #

B-Y B-V

B-Victoria lineage

B-Yamagata lineage

Page 34: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

HI reactions of influenza type B viruses

By NIID

Page 35: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

HI reactions of influenza type B virusesB/Victoria-lineage

By NIMR

Page 36: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

HI reactions of influenza type B viruses B/Yamagata lineageTable 7. Antigenic analyses of influenza B viruses (Yamagata lineage)

Viruses Collection B/Fl3 B/Eg B/Fl B/Bris B/Barc2 B/Eng2 B/Vall2 B/Ban B/Indi

date 4/06 144/05 4/06 3/07 143/08 145/08 18/08 3333/07 1/08Sh 478 F3/07 F19/07 F24/07 F11/08 F9/08 F10/08 F21/08 CDC174/08

REFERENCE VIRUSES

B/Egypt/144/2005 01/05/2005 E2 \2 2560 160 320 640 10 40 20 160 1280B/Florida/4/2006 15/12/2006 E2 \1 5120 160 640 640 10 80 20 160 1280B/Brisbane/3/2007 03/09/2007 E2 \2 5120 160 640 640 10 80 20 160 1280B/Barcelona/143/2008 06/01/2008 MDCK1 \2 5120 80 160 320 320 160 320 320 640B/England/145/2008 Ex \2 320 40 < 40 10 160 10 20 640B/Valladolid/18/2008 18/02/2008 MDCK1 \2 2560 80 160 80 160 160 320 160 1280B/Bangladesh/3333/2007 19/08/2007 E4 \1 2560 80 160 160 20 40 20 160 1280B/Indiana/1/2008 10/03/2008 E2 \1 1280 40 80 160 20 40 20 320 640

TEST VIRUSES

B/Mendoza/R530/2008 Aug-08 M2 /1 5120 160 160 320 160 160 160 320 NDB/Ghana/MH-31/2008 19/08/2008 MDCKx /1 2560 160 160 320 160 160 320 320 NDB/Dakar/06/2008 19/08/2008 MDCK2 /1 5120 160 640 640 320 640 320 640 NDB/Ghana/MH-36/2008 29/08/2008 MDCKx /1 2560 160 160 320 160 160 320 320 NDB/Ghana/NG-PK-01/2008 09/09/2008 MDCKx /1 5120 160 160 160 320 320 320 320 NDB/Hong Kong/1355/2008 09/09/2008 MDCK2 \2 2560 80 160 160 160 160 160 320 NDB/Ghana/MH-41/2008 12/09/2008 MDCKx /1 2560 80 40 40 80 160 160 160 NDB/Hong Kong/1372/2008 25/09/2008 MDCK2 \1 5120 160 160 160 160 320 160 160 640B/Ghana/FS301/2008 09/10/2008 MDCK2 \1 5120 80 160 320 320 160 320 320 640B/Hong Kong/1374/2008 17/10/2008 MDCK2 \1 2560 80 160 320 160 160 160 160 640B/Ghana/FS347/2008 31/10/2008 MDCK2 \1 2560 80 80 80 160 160 320 160 1280B/Ghana/FS351/2008 31/10/2008 MDCK2 \1 5120 80 160 80 320 160 320 320 640B/Paris/236/2008 03/11/2008 C2 \1 640 40 < < 10 80 40 40 NDB/Ghana/FS355/2008 04/11/2008 MDCK2 \2 640 < < < 80 80 160 80 NDB/Ghana/FS383/2008 17/11/2008 MDCK2 \1 5120 160 320 640 640 320 640 640 1280B/Ghana/FS385/2008 18/11/2008 MDCK2 \1 5120 160 160 160 320 320 320 320 1280B/Ghana/FS428/2008 09/12/2008 MDCK2 \1 5120 80 80 80 160 160 320 160 640B/Ghana/FS433/2008 11/12/2008 MDCK2 \3 2560 40 80 80 160 160 160 160 NDB/Ghana/FS435/2008 12/12/2008 MDCK2 \3 2560 40 80 80 160 80 160 160 NDB/Ghana/FS388/2008 18/11/2008 MDCK2 \2 2560 80 80 80 160 160 320 160 NDB/Switzerland/1334249/2008 04/12/2008 MDCK1 \1 2560 80 160 320 320 160 320 320 NDB/Egypt/133/2009 14/01/2009 Ex \1 160 < < < < 20 < 10 ND

1. < = <40; 2. < = <10; 3. hyperimmune sheep serum

ND = not done

Vaccine strains

Haemagglutination inhibition titre1

Passage

History

Post infection ferret sera

By NIMR

Page 37: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Victoria Yamagata• CDC (Oct-) 71 [60%] 48 [40%]

low reactors (77%) (23%)• NIID (Oct-) 18 [40%] 27[60%]

Low reactors (94%) (67%)• NIMR 17 [44%] 22[56%]

Low reactors (76%) (14%)VIDRL (Oct-) 340 [67%] 167 [33%]

Low reactors (94%) (62%)

Total 446 [63%] 264 [37%]Low reactors (91%) (51%)

B low reactors in HI assays in WHOCCs

Page 38: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

10 nucleotides

B/Brisbane/60/2008-like

Evolutionary Relationships Among Influenza B (Victoria Lineage) HA Genes

B/Malaysia/2506/2004

K165N

Chinese clade

By Melbourne C.

Page 39: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Evolutionary Relationships Among Influenza B (Yamagata Lineage) HA Genes

10 nucleotides By Melbourne C.

Page 40: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

March-July 2009

Page 41: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By NIMR

HI reactions of influenza type B virusesB/Victoria-lineage

Page 42: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By CDC

Page 43: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.
Page 44: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By Cambridge Univ.

Page 45: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

B/Victoria-lineage HA

By NIID

Vaccine virus

Chinese viruses

Page 46: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

By CDC

B/Yamagata-lineage HA

Vaccine virus

Page 47: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

Summary for influenza B virusesOct 2008-Feb 2009

• Influenza B viruses circulated in many countries however regional outbreaks were limited.

• Viruses of both B/Victoria/2/87 and B/Yamagata/16/88 lineages continued to co-circulate in many countries

• B/Victoria-lineage viruses predominated in most countries and were mostly antigenically closely related to B/Brisbane/60/2008.

• Viruses mainly from China fell into a separate phylogenetic clade

• B/Yamagata-lineage viruses were antigenically closely related to B/Florida/4/2006 & B/Brisbane/3/2007 vaccine viruses.

• Three phylogenetic clades were apparent but were antigenically indistinguishable.

Mar - July 2009

• B/Victoria-lineage viruses predominated and were mostly antigenically closely related to vaccine strain B/Brisbane/60/2008.

• Many viruses isolated in China were closely related to B/Fujian Gulou/1272/08 and B/Hubei-Songzi/51/08.

• B/Yamagata-lineage viruses were antigenically closely related to B/Florida/4/2006 and mostly fell into their HA sequences of the B/Bagladesh/3333/07 clade.

Page 48: Update on Influenza Virus Surveillance Findings in 2008/09 Season in Northern Hemisphere Who Collaborating Center for Reference and Research on Influenza.

WHO Collaborating Centers

(US-CDC, NIMR, Melbourne)

Cambridge University

NICs

(China-CDC, Korea-CDC, NHL-Myanmar,

NCLE-Lao PDR, NIH-Mongolia and other NICs of WHO GISN)

Taiwan-CDC

Local PHLs in Japan

Acknowledgement