INTERIM REPORT

WHO INFLUENZA CENTRE

LONDON

MARCH 2006

1

CHARACTERISTICS OF HUMAN INFLUENZA AH1N1, AH3N2 AND B VIRUSES ISOLATED OCTOBER 2005 TO FEBRUARY 2006 WHO Collaborating Centre for Reference and Research on Influenza National Institute for Medical Research The Ridgeway Mill Hill London, NW7 1AA Dr. Alan J. Hay (Director) Dr. Yi Pu Lin (Assistant Director) Miss Victoria Gregory Mr. Michael Bennett Tel: 020 8959 3666; 020 8816 2152 Fax: 020 8906 4477 Email: ahay@nimr.mrc.ac.uk; lyipu@nimr.mrc.ac.uk

2

Of some 200 influenza viruses isolated in 19 countries since October 2005, approximately half (49%) were A H1N1 and 16% were A H3N2 (Table 1). Influenza B viruses accounted for 35% of isolates, 75% of which were of the B/Victoria lineage and 25% were of the B/Yamagata lineage. AH1N1 viruses The majority of H1N1 viruses were antigenically closely related to the current vaccine strain A/New Caledonia/20/99 and to the more recent reference viruses A/Netherlands/128/2004 (MDCK), A/Hong Kong/2367/04 (MDCK) and A/Thessaloniki/24/2005 (egg) (Table 2). The HA sequences of recent isolates fell into two phylogenetic groups (Figure 1): 1) represented by A/Hong Kong/2367/2004 and characterised by the amino acid changes T82K, Y94H, R145K, R208K and T266N (red in Figure 1), and prominent among Asian isolates; 2) represented by A/Thessaloniki/24/2005 and characterized by the changes Y252F and V314A (blue in Figure 1) (Table 3). There was relatively little change in the sequences of these variants over the past 12-18 months; however, the proportions of the former increased to a level similar to that of the latter. No consistent differences in HI were observed between variants of the two phylogenetic groups. The NA sequences of a number of the latter viruses were also shown to be similar to those of earlier isolates (Figure 2, Table 3); however, others, represented by A/England/488/2005, possessed the amino acid changes A16T, S59N, I117T, V234M, N273S, T339N and D383N and were more closely related to the NAs of viruses with the former group 1 HAs. AH3N2 viruses Of the relatively few H3N2 viruses received, the majority were antigenically closely related to the recent MDCK-grown reference viruses A/Hong Kong/4443/2005 and/or A/Annecy/1138/2005. In general, they gave low HI titres, relative to the homologous virus, with egg-grown vaccine strains, A/California/7/2004 and A/New York/55/2004, and the recently recommended strain A/Wisconsin/67/2005. These differences are due in large part to the cells in which the viruses are grown. The majority of HA sequences of recent isolates were characterized by the changes S193F and D225N and represented by A/Hong Kong/4443/2005 and A/Wisconsin/67/05 (red in Figure 3). A number fell within the older phylogenetic group characterized by amino acid changes V112I, N145S and K173E, with additional changes D188Y, G175V or S199P (blue in Figure 3). M2 protein sequences obtained for viruses with HAs within the former group all possessed N31, indicative of amantadine resistance. Influenza B viruses The majority of B/Yamagata-lineage (HA) viruses were antigenically closely related to the recent egg-grown reference strains, B/Egypt/144/2005 and B/Florida/7/2004, and gave reduced HI titres with the vaccine strains B/Shanghai/361/2002 and

3

B/Jiangsu/10/2003 (Table 6). Some were antigenically more closely related to B/Jiangsu/10/03. Most of the HA sequences of recent isolates were similar to those of viruses circulating during 2005 and were characterized by the change V252M, many with an additional change P108A, relative to the HA sequence of B/Shanghai/361/2002 (green in Figure 5, Table 8). A number of viruses from Norway had the additional changes N166Y and G230D. Most of the B/Victoria-lineage (HA) viruses were antigenically closely-related to the MDCK-grown reference strain B/Hong Kong/45/2005 (Table 7). However, many gave reduced HI titres with the egg-grown vaccine strain B/Malaysia/2506/2005. Most of the HA sequences of recent isolates fell into one of two principal phylogenetic groups (Figure 6): 1) characterized by the amino acid changes R48E, K80R and K129N relative to B/Shandong/7/97, and represented by B/Hong Kong/45/2005 and B/Malaysia/2506/2004 (red in Figure 6, Table 8); 2) characterized by the changes, K80E plus V190I and represented by B/Ohio/1/05 (blue in Figure 6). Some sequences have additional changes N75K and V177I, such as B/Toulouse/44/06. We did not observe any obvious differences in HI tests between viruses belonging to the different phylogenetic groups. Acknowledgements In addition to data received from the other 3 Collaborating Centres, sequence data for viruses isolated during this period were received from Influenza Centres in Denmark, Germany, Italy, Norway, Spain, Sweden and the U.K. (indicated in Figures by suffixes).

4

Table 1: Human influenza isolates, October 2005- February 2006

H1N1 H3N2 BCountry Yamagata Victoria

lineage lineage

OctoberSweden 1Switzerland 1

NovemberFrance 1Germany 1Hong Kong 3Madagascar 4 1Sweden 2UK 1

DecemberDenmark 1Egypt 4France 6 1 4 6Hong Kong 4 2 6Ireland 1Madagascar 22Netherlands 1Norway 2 2 7 2Portugal 1Sweden 2UK 3 1 5

JanuaryDenmark 1Egypt 16 4Finland 1France 1 1 1Hong Kong 5Iceland 2Ireland 1Italy 1 1Latvia 2 3Netherlands 1 2Norway 3 2 3 5Portugal 7 3Slovakia 2Spain 4 3Sweden 2 2 1 1Switzerland 1 1UK 1

February

Egypt 1Latvia 1 6 5Portugal 4 4Slovakia 1Spain 3 1

Total = 208 101 34 18 5549% 16% 9% 26%

5

Table 2. Antigenic analyses of influenza A H1N1 and H1N2 viruses

Viruses Isolation A/Beij A/NC A/Eg A/HK A/Neth A/ThessDate 262/96 20/99 96/02 2367/04 128/04 24/05

A/Beijing/262/96 1280 320 320 640 320 640A/New Caledonia/20/99 80 640 640 640 320 640A/Egypt/96/02 80 320 640 640 320 320A/Hong Kong/2637/04 80 320 320 1280 320 320A/Netherlands/128/04 160 320 640 1280 2560 2560A/Thessaloniki/24/05 160 320 640 1280 2560 2560

A/Switzerland/8761/2005 19.10.05 MDCKIx \1 80 640 320 NT 640 1280A/Baden-Wurttemberg/362/2005 16.11.05 MDCKx \1 < 80 < 160 160 80A/Lisbon/94/2005 4.12.05 MDCK1 \2 160 640 640 2560 2560 1280A/Madagascar/2309/2005 15.12.05 MDCK1 \1 160 640 320 1280 1280 1280A/Hong Kong/4922/2005 20.12.05 MDCK2 \1 40 320 320 640 640 320A/Egypt/136/2005 21.12.05 E2 \1 40 320 320 NT 320 320A/Lyon/CHU/2/06 28.12.05 MDCK2 \1 80 640 320 NT 1280 1280A/Norway/30/2006 28.12.05 MDCK1 \1 160 640 640 NT 640 1280A/England/488/2005 30.12.05 MDCK3 \1 40 320 320 640 640 640A/Clermont-F/26/06 2.1.06 MDCK2 \1 160 640 640 NT 2560 2560A/Stockholm/3/2006 4.1.06 MDCK1 \1 80 320 320 640 640 640A/Hong Kong/35/2006 7.1.06 MDCK2 \1 160 320 640 2560 2560 1280A/Switzerland/4243/2006 10.1.06 MDCKIx \2 80 320 640 1280 1280 1280A/Norway/195/2006 17.1.06 MDCK1 \1 160 640 640 2560 2560 1280A/Lisbon/13/2006 18.1.06 MDCK1 \1 160 640 320 2560 2560 2560A/Egypt/214/2006 1.2.06 E3 160 320 320 1280 2560 2560A/Latvia/1951/2006 11.2.06 MDCK1 \1 160 320 160 640 1280 1280A/Barcelona/259/2006 13.2.06 MDCKx \1 160 640 320 2560 2560 2560

1. < : <40

Haemaggutination inhibition titre1

Post infecton ferret sera

6

h1iraq69806csj h1iraq73706csj

sydney54905auss california2605cdcn

sydney6505aus newjersey1005cdcd

wellington1105saus h1egypt13605d

victor34605gaus newcastle905saus brisbane22705saus sydney55005auso perth24805laus southaustralia4705laus victoria30405uaus brisbane26505oaus

india569805lcdc victoria35605auss southaustralia12705gaus

southaustralia6805laus auckland305laus

h1england48805d h1jhb45205u

sendai9005japl wisconsin7305cdcn

paraguay07605cdca h1stpeter1005y

h1krasn16e05y india521005lcdc

h1stockholm1805se jhb14605sa

sendai42005jp sapporo482005jp

hiroshima1306japj hiroshima506japj

hiroshima1406japj aichi16905japn h1lisbon9405d

florida3e05cdcd h1latvia421605a

h1krasn46e05y ulaanbaatar142905cdcn

jianxi16005cdcm A/Thessaloniki/24/2005

chongqing96805cdco wuhan30005gcdc

chongqing97005cdco wuhan28205japg

kawasaki50405japn wuhan29305cdcg shenzhen14105cdco

shenzhen4205japu shenzhen4905japu

colorado2005cdcn badenw36205gen

fukui3805japd aomori1305japd

india613405gcdc newhampshire105cdcn

ukh054800260hpa india360105ycdc

chongqing97705cdco chongqing97505cdco california2705cdcn

chongqing92805cdcs gansu5705cdcn

shenzhen4305japu A/Hong Kong/2637/2004

shenzhen86gcdc shenzhen5805japg

tianjin45205cdcs jianxi68005scdc

ishikawa8405japd hiroshima106japj

india580405acdc cheju96005cdcd

korea3805cdcd tokyo670805japs

A/NEW CALEDONIA/20/99 A/BEIJING/262/95

bayern795 jobg8296

10 Nucleotides

Figure 1. Phylogenetic comparison of H1 HAs

Y252FV314A

V166AW251R

T82KY94HR145KR208KT266N

7

n1krasn16e05y n1krasn46e05y n1stpeter1005y

bangkok187604cdcs novosibrisk22005cdcm

novosibrisk52005cdcm kentucky12005cdcj n1stockholm1805

suphan212904cdco hk455504cdcs bangkok172404cdcs

suphan213004cdco suphan213104cdco hk458004cdco

bangkok175504cdcs bangkok141004cdcg

nontha173904cdcs ireland1389204o

florida304cdcd nether12804s bangkok146704cdcg denmark1705f

england4004y prachin174904cdcs bangkok175704cdcs romania4932005cdcm A/Thessaloniki/24/05 prachin181704cdcs

thailand812005cdcf n1belgium73305f

h1lisbon9405dn1 h1hk3506jn1

h1egypt13605dn1 malay151304cdcl mx2682003cdc

israel203f moscow703m

paris65003n n1jhb45205u reunion140903

lyonchu2882404l A/Hong Kong/2765/04

bangkok146804cdcg bangkok174104cdcs

n1badenw36305gen ayatt211104cdco

h1england48805dn1 h1egypt3905nn1

indonesia9512005cdcj newcal304cdca

sing1404cdcm n1tw148601cdcl

n1hk74701 h1hk84102a

h1khab6502m h1khab6002m

n1zag298001y n1hungary203f n1stock801u

palencia502n1 A/NEW CALEDONIA/20/99

n1brat4700 n1ice101

n1fin13102f n1asc104100

n1lyon65101 n1mor6901

n1brazil20200 n1bang1000

n1ost80198 n1hon24296

n1job15997 A/BEIJING/262/95

n1wuh37195

Figure 2. Phylogenetic comparison of N1 NAs

10 Nucleotides

E332KN450D

V234M D382N

8

Variant Group Representative strain Amino acid changes1

HA NA

1 A/Thessalonika/24/05 V166A V48IW251R E332KY252F N450DV314A

A/England/488/05 V166A A16TW251R S59NY252F I117TV314A V234M

N273ST339ND382N

2 T82K E214GY94H R222Q

R145K V234MV166A D382NR208KW251RT266N

Table 3. Amino acid changes characteristic of H1N1 sequence variants

1. Relative to A/New Caledonia/20/99 (H1N1)

A/HK/2637/04

9

Table 4. Antigenic analyses of influenza A H3N2 viruses

Viruses Isolation A/Pan X-147 A/Shan A/Cal A/NY A/Ann A/HK A/WisDate 2007/99 (Wy/3/03) 1219/04 7/04 55/04 1138/05 4443/05 67/05

F2/01 F11/03 F14/04 F31/05 F6/05 F33/05 F24/05 CDC

A/Panama/2007/1999 Ex 5120 1280 320 40 < < 40 <A/Wyoming/3/2003 Ex 1280 2560 1280 640 1280 160 160 640A/Shantou/1219/2004 MDCKx 320 160 1280 640 1280 160 320 320A/California/7/2004 SpfCk3, E3 160 640 2560 2560 2560 320 640 1280A/New York/55/2004 < 320 1280 1280 1280 320 320 1280A/Annecy/1138/2005 < 40 320 160 320 320 320 160A/Hong Kong/4443/2005 < 80 160 160 320 320 320 160A/Wisconsin/67/2005 80 160 1280 640 1280 1280 2560 2560

A/Hiroshima/52/2005 unknown E3 \1 < < 640 640 1280 320 640 NTA/Umea/9/2005 10.11.05 MDCK1 \1 < 80 160 160 40 40 320 160A/Madagascar/2102/2005 17.11.05 MDCK3 \1 < 640 1280 320 320 640 160 NTA/Ireland/12182/05 Dec-05 MDCK2 \3 < 80 160 320 80 80 320 160A/Hong Kong/4920/2005 19.12.05 MDCK2 \3 < < 80 160 < 160 160 80A/Norway/28/2006 20.12.05 MDCK1 \1 < < 160 80 160 160 160 80A/Stockholm/1/2006 22.12.05 MDCK1 \1 40 80 320 320 160 160 320 160A/Netherlands/548/2005 26.12.05 MDCK1 \1 < 80 320 320 320 640 640 640A/Denmark/112/2005 28.12.05 MDCK2 \1 < < < 40 40 80 80 80A/Latvia/222/2006 4.1.06 MDCK1 \3 < 40 160 160 320 320 320 160A/Lyon/21/06 4.1.06 MDCK2 \1 < < 160 160 320 160 160 80A/Finland/634/2006 6.1.06 MDCK2 \1 < 40 160 160 320 80 160 160A/England/4/2006 9.1.06 MDCK1 \2 < 40 160 320 160 160 160 80A/Iceland/2/2006 9.1.06 MDCK3 \1 < < 80 160 < 160 80 80A/Stockholm/6/2006 14.1.06 MDCK1 \1 < 40 80 160 80 160 160 160A/Norway/143/2006 16.1.06 MDCK1 \1 < 40 < 320 320 320 320 320A/Slovakia/134/2006 6.2.06 MDCK1 \1 < 40 160 320 160 160 320 640A/Latvia/2047/2006 14.2.06 MDCK1 \1 < < 80 160 160 160 160 80

1. <,<40

Haemagglutination inhibition titre1

Post infection ferret sera

10

florida905cdcd korea705cdcd

texas5405cdcn h3norway2806d05

utah705cdcd mexico226405cdcn

texas56o5cdcn georgia106cdcj colorado1605cdcd taiwan60405cdcd h3lyon2106j

yamagata22705japn arvaikheer210105cdcd

srilanka14605ausn hawaii2205cdcn sukhbaatar158705cdcd

h3annecy114005lha h3annecy114705lha canadarv134105cdcn

oregon905cdcn hiroshima5405japn hiroshima5205japo

hiroshima5205japn hiroshima5305japn hyogo3905japd hyogo3605japd

fukui3705japn osaka2905japn sakai4605japd

kawasaki50205japn pennsylvania505cdcn

california20e05cdcn h3annui1239e05cdcg

nara2605japg okayama2405japn

kobe7405japo kyotoc905japn

A/Hong Kong/4443/2005 tianjin45105japg

h3ncarolina1305cdcg shiga2305japd

yamanashi6105japn h3wuhan28305cdcg

A/WISCONSIN/67/05 uruguay34e05cdcu

victoria27005ausn massachusetts1005cdcn iowa1605cdcd idaho905cdcn

guangdong31805japa mie2505japs victoria26705ausn mississippi1905cdcn washington1005cdcn umea905nse h3tianjin45905cdcs denmarkh7554305dk

stockholm206jse wisconsin68e05cdco brisbane23405auss h3latvia22206j

stockholm2105gse nagasaki5005japs

A/Wellington/1/04 stockholm2405nse stockholm2305nse hiroshimac905japo

stockholm106jse stockholm2505dse

thailand30805ausg aomori1205japn

kobe7305japs otago205ausg waikato1205auss darwin705ausg

victoria51205ausu townsville14905auss

h3finland63406j turkey222506j parma106it

parma206it madagas134105g

madagas161305s norway80704nwg

venezuela415505cdcg h3stpeter1205u

A/New York/55/2004 brazil2363e05cdc

A/California/7/2005 venezuela6971ecdcy

shantou121904g cchurch2803u

A/Wyoming/3/2003 A/FUJING/411/02

10 Nucleotides

Figure 3. Phylogenetic comparison of H3 HAs

D225N

S193F

G275V

N145S

S199P

V112IK173E

11

A/Hong Kong/4355/2005 n2hk423105u hk28452005cdcy

hk28312005cdcy h3lyon2106jna h3hiroshima5205ona

h3anhui123805gna h3annecy114005ln2 h3annecy114705ln2 n2umea805 hk28972005cdcy hk29262005cdcm n2malaysia73505aus

h3latvia22206jna hk22872005cdcy

umea905se h3norway2806dna

n2stockholm2005 n2stockholm206se

n2stockholm1105 n2stockholm405

n2goteborg105sej trieste805j n2stock205sej

n2stock105sej A/California/7/2004 A/New York55/2004 n2malmo204sed

n2umea405sej wy9e05cdcf

nh12e2004cdcd n2victoria52305ausn

bayern1504o agr5605cdcy

n2finland63406fnj h3finland63406jna

ci214805cdcf agr5505cdcy

n2stpet1205y hk298204cdc

hk297604l hk459332005cdc

mos705cdcf n2stock305sej

n2jhb39105y n2jhb12205y paris65904d

h3saudi44105mn2 h3saudi30705mn2

n2ireland959104o n2baleares72004n

n2ningbo99704cdcs n2stock1904sen

kyunggi2052005cdcf barcel10405j

n2umea305sej h3sing3704u

iceland605j incheon2432005cdcf

n2lisbon304 stpete4205cdcm

thailand1292005cdcm n2stockholm2505se

n2goteborg205 n2umea705

n2victoria51205ausu ms5e2004cdcd

n2reunion58104s indonesia29422005cdcm

finland48704d brazil175904cdc

n2newcal704cdcy A/Wellington/1/2004

japan12004cdc n2sing3604cdcu

shantou54004a shantou56404a

n2shantou121904g n2wuhan26904cdcg shantou237a03g

israel403m shantou35103l

A/WYOMING/3/2003 n2neth24603u uk186103

A/FUJIAN/411/02 hk155002j

n2hong200 n2mosc1099

n2lyon124200

10 Nucleotides

Figure 4. Phylogenetic comparison of N2 NAs

A/WISCONSIN/67/05

D193N

12

Variant group Representative strain

HA NA

1 A/Hong Kong/4443/05 S193F D93ND225N (D151G/N)

2 A/Stockholm/23/05 V112I (E221K)N145SK173E

(D188Y)(G275V)

1. Relative to A/California/7/04.

Table 5. Amino acid changes characteristic of H3N2 sequence variants

Amino Acid changes1

13

Table 6. Antigenic analyses of influenza B viruses (Yamagata lineage)

Viruses Isolation B/Sich B/Shai B/Jiang B/Eg B/Fldate 379/99 361/02 10/03 144/05 7/05

B/Sichuan/379/99 160 320 < 160 160B/Shanghai/361/2002 160 640 40 160 160B/Jiangsu/10/2003 80 160 320 80 80B/Egypt/144/2005 160 160 40 320 320B/Florida/7/2005 80 160 < 320 320

B/Stockholm/2/2006 unknown MDCK1 \1 80 160 < 160 320B/Norway/1967/2005 7.12.05 MDCK1 \1 40 160 80 320 320B/Norway/1991/2005 20.12.05 MDCK1 \1 40 80 < 320 160B/Lyon/CHU/51.486/05 23.12.06 MDCK2 \1 40 160 320 160 320B/Norway/2007/2005 29.12.05 MDCK1 \1 40 80 < 160 80B/Lyon/CHU/1.122/06 2.1.06 MDCK2 \1 40 160 320 80 160B/Norway/17/2006 2.1.06 MDCK1 \1 40 160 80 320 160B/Norway/26/2006 3.1.06 MDCK1 \1 40 160 40 320 160B/Denmark/1/2006 9.1.06 MDCK2 \1 40 40 40 320 160B/Stockholm/2/2006 Jan-06 MDCK1 \1 80 160 < 160 320B/Norway/174/2006 19.1.06 MDCK1 \1 80 80 320 80 320B/Genoa/1/2006 23.1.06 MDCK1 \2 80 80 40 160 160B/Lyon/CHU/1.122/06 2.1.06 MDCK2 \1 40 160 320 80 160B/Denmark/1/2006 9.1.06 MDCK2 \1 40 40 40 320 160

1 <, <40

Haemagglutination inhibition titre1

Post infection ferret sera

14

bwellington905jap auckland3205ausy

wellington905ausy sendai2205japf perth11105auso

blyon112206j bnorway1706j

bthailand27305ausl bhk78205cdcu aichi17105japf

bhawaii11e05cdcu kitakyusyu2505japm

bdarwin105ausg bbrazil2151e05cdcg

bvictoria53105auso victoria53005auso

bjhb17905japu bjhb17905u

bphilippines56105ausu bperth11005auso bbelgium86405m tokyo12605japf

yamagata7005japf akita1805japm sapporo17705japa bphilippines60505auss bbrisbane3005ausg bhawaii12e05cdcy

philippines1040ausn bhstockholm1005se bbrisbane305jap brisbane505ausu sydney205ausy thailand13705ausm toyama4305japm btownsville505ausl

bsaustralia3905ausl bhstockholm805se bkenya705cdcl vsetin12105m blisbon3405m macau39405ausa ny1405cdcm nevada505cdca

sydney305aus bleon3005a bslovakia38805m

kentucky405cdcm boklahoma205cdcl california1405cdcn

kuwait105cdcn ehime4005japf

genova106it B/Egypt/144/05 balgeria0305f neth12904s

canadarv132805cdcn honduras146505cdcd

biran22505 B/Florida/7/04 madagas151705g

umea105d bbelem432e05cdcj

ncaledonia1005ausu victoria50705ausu

hk6404u shantou121204g B/JIANGSU/10/03

chongqing120405cdca blatvia490105y

tula1405m christchurch3805ausu

B/SHANGSHAI/361/02 B/YAMANASHI/166/98

B/SICHUAN/379/99 B/PANAMA/45/90

B/BEIJING/184/93 harbin794

Figure 6. Phylogenetic comparison of B HAs (Yamagata lineage)

10 Nucleotides

P108A

V252M

15

Table 7. Antigenic analyses of influenza B viruses (Victoria lineage)

Viruses Isolation B/Shan2 B/Shan B/Tehr B/Bris B/HK B/Maldate 7/97 7/97 80/02 32/02 45/05 2506/04

B/Shandong/7/97 1280 320 160 160 160 320B/Tehran/80/2002 1280 160 160 320 160 320B/Brisbane/32/2002 640 80 160 160 80 80B/HK/45/2005 1280 80 80 80 160 160B/Malaysia/2506/2004 640 160 80 160 80 320

B/England/474/2005 22.12.05 MDCK3 \1 1280 160 < < 80 80B/Lyon/CHU/52.133/05 26.12.05 MDCK2 \1 2560 160 < < 160 80B/Toulouse/43/06 13.12.05 MDCK2 \1 1280 160 < < 160 40B/Norway/1992/2005 20.12.05 MDCK1 \1 1280 160 < < 160 80B/Toulouse/44/06 21.12.05 MDCK2 \1 2560 160 < < 160 40B/Hong Kong/15/2006 30.12.05 MDCK2 \1 1280 320 80 40 160 160B/Switzerland/4081/2006 5.1.06 MDCKIx \1 1280 160 < < 160 80B/Stockholm/1/2006 11.1.06 MDCK0 \1 1280 160 40 40 80 160B/England/465/2005 2.12.05 MDCK3 \1 1280 320 40 40 160 80B/Egypt/208/2006 25.1.06 C1 E1 1280 80 40 < 80 160B/Ireland/2193/2006 Jan-06 MDCKx \1 1280 160 < < 160 80B/Genoa/2/2006 30.1.06 MDCK1 \1 1280 160 < < 320 160B/Netherlands/002/2006 19.1.06 MDCK1 \1 2560 160 < < 160 80B/Norway/196/2006 24.1.06 MDCK1 \1 1280 160 < < 160 80B/Slovakia/117/2006 30.1.06 MDCK1 \1 1280 40 < < 160 80B/Latvia/1844/2006 9.2.06 MDCK1 \1 1280 40 < < 160 80B/Lisbon/22/2006 4.2.06 MDCK1 \1 1280 40 < < 160 80B/Barcelona/258/2006 10.2.06 MDCKx \1 1280 80 < < 160 80

1 <, <402 hyperimmune sheep serum

Haemagglutination inhibition titre1

Post infection ferret sera

16

waikato2805ausu bcchurch6505ausu auckland5005ausy

wellington2105ausu bvictoria50505jap

aichi11305jap billinois1305jap

bbrisbane6905ausg bbrisbane10305auso ohio1x1905cdc ohio1e405cdcf

brisbane605ausu bcchurch12005ausl

washington505cdca chile67552005cdcy B/OHIO/1/05 bhk79705cdcl victoria51705aus

michigan305cdcd chile6218e2005cdcu bnewjersey605cdco bbrisbane4205ausg bbrisbane2905ausg newyork2e2005cdcm

victoria50505ausy bperth9805ausg bengland47805d jhb2705sa bjhb2705japy

jhb11005sa btoulouse4406d05

bserbia205 trieste105it argentinar7005cdcu breunion115405y

bargentinar56905cdcl blatvia504305y

hawaii3304cdcn bhawaii3304 taiwan47305cdcm bgifu1005jap

bjhb40305u bindonesia888105ausy canadarv134305cdcn

bshenzhen5905japg bhk1506d05

saustralia905ausu bsingapore1405cdcy

bsaustralia3405ausl auckland1405ausy bwaikato15005ausu

bnorway199205d genova206it

bswitz408106j bguangdong32105cdca bchongqing86705japg

bindonesia692005ausy bphilippines37105ausu bsydney1905aus romania70005cdcm malaysia41905ausa kawasaki50705japd

B/MALAYSIA/2506/04 bmalaysia78305ausg brisbane10205ausn bvictoria12205ausg bjhb38205u bnepal133705cdc bmalaysia250604x17 turkey38905a macau38805ausa

taiwan12105jap B/Hong Kong/45/05f perth11205ausn

sakai6305japd bindonesia807405cdcu

bnepal1331e05cdcl bindonesia850805cdcu

bphilippines14505ausg madagas106205l madagas111405l

madagas7213404u iran19705

bris3202ausl tehran8002f beijing24396

shizuo2098 B/SHANDONG/7/97

hongkong7694 hong7096

B/HONG KONG/330/01 B/VICTORIA/2/87

beij187

Figure 7. Phylogenetic comparison of B HAs (Victoria lineage)

V190I

K80E

R48EK129N

K80R

10 Nucleotides17

HA Lineage Representative strain Amino acid changes

HA NA

Yamagata1 B/Egypt/144/05 V252M T42QT49I

K186RN219KN235DS244PD329NN342DD392EE436T

B/Belgium/864/05 V252MP108A

Victoria2 B/Malaysia/2506/04 R48E S50PK80R P51S

K129N I248VV271IL396FD463N

B/Ohio/1/05 K80E K125NV190I I248V

K373EE404G/K

1.

Table 8. Amino acid changes characteristic of recent B sequence variants

Relative to B/Shanghai/361/02. 2. HA relative to B/Shandong/7/97; NA relative to B/Tehran/80/02.

18

il13e2005cdcf B/OHIO/1/05

switz558004d michigan202005cdcm ci6218e2005cdcy

bnswitz408106j trieste105j

norway54405nwf bayern104d

bnjhb2705y argentinar702005cdcu

hawaii1304cdcu hawaii2004cdco

okinowa104 phitsan205304cdco

bnparma304it bnjhb40305u

bnjhb38205u B/Hong Kong/45/05

bnhk1506d05 hk310e04cdcn B/MALAYSIA/2506/04

turkey192005cdca jhb2204u madagas7213404u

btehran8002f india57742005cdcf

bnmarit21902y petropav152005cdcm

romania7742005cdcm btula1405m

hk4504u fujian43004cdcs

shantou121204g paris196204a shizuoka5804cdcj

shantou105404g B/JIANGSU/10/03

B/SHANGHAI/361/02 B/Sichuan/379/99

B/YAMANASHI/166/98

lisbon305j B/Florida/7/04 bnstockholm205se

canada58004cdcu bnumea105sed bnnorway110204n

bnumea205sea bnstockholm405se

brisbane504cdcs incheon3012005cdcf bnstockholm905se B/Egypt/144/05

bnstockholm505se oslo7104j

england2304na victoria50904cdcs

oslo43504mnw neth12904a

colorado504cdcn bnnorway193105nw

cchurch3304cdcg bnjhb17905u bnstockholm1005sej

newyork142005cdcm bnstockholm605sey

bnstockholm105sej genova106

sachsen104d bnharb794

B/BEIJING/184/93 bnhong7096

bnhong7094 bnjobg2694

B/HONG KONG/330/01 B/SHANDONG/7/97

bnyama1688 bnpan4590

Figure 8. Phylogenetic comparison of B NAs

K125N

K373E

I248V

L73F

P42TD342N

P42QN219KD329ND392EE436T

10 Nuleotides

Vic HA/Yam NA Reassortant

19