Antigenic cartography of H5 viruses

Ron A.M. Fouchier, PhD.Professor Molecular Virology

National Influenza Center and Department of Virology, Erasmus MC

14th joint annual meeting of the national reference laboratories for AI and ND

Brussels, April 10, 2008

A/H5N1 virus- Genetic variation -

Source: www.who.intwww.offlu.net

A/H5N1 virusAntigenic properties; hemagglutination inhibition (HI)

Source: www.who.int

Antigenic cartography- H3N2, 1968-present -

Smith et al., Science 305, 371-376 (2004)

Antigenic cartography:Employs a suite of software packages to analyze binding assay data with MDS algorithms. Enables quantitative analysis and visualization ofantigenic properties of influenza virus (HI data)

Multi DimensionalScaling (MDS)

algorithms

Error function:E=∑ije(Dij,dij)

Antigenic cartography- Applications -

Smith et al., Science 305, 371-376 (2004); Method description + application to flu (A/H3N2)

Smith et al., Discovery Medicine, 4, 371-377 (2004). Method explanation in lay terms

Real-time application for H3N2 vaccine strain selectionwithin the WHO global influenza surveillance network

Can these methods be applied to H5 HI datasets?

H5 influenza - Antigenic map, up to 2005/2006 -

Vaccine strains:A/Vietnam/1194/2004-like virusA/Indonesia/5/2005-like virusA/Bar headed goose/Qinghai/1A/2005-like virusA/Anhui/1/2005-like virus

Data from EMC & WER

RBC: horse, turkey, chicken

Sera:Ferret post infectionFerret post vaccinationRabbit post vaccinationBird post infectionBird post vaccination

NOT compatible with:Chicken hyperimmune sera

H5 antigenic cartography- Using hyperimmunized chicken sera to make maps -

Data provided by VLA, Jill Banks & Ian Brown

-Very robust maps; excellent HI data-Double immunized chicken sera

H5 influenza map- Conclusions -

- H5 HI data from different labs (e.g. EMC, CDC, St Jude, HKU) are in agreement (but NOTwith labs using hyperimmunized chicken antisera for HI)

- Clades that include viruses affecting humans (0, 1, 2.1, 2.2, 2.3) are antigenically distinct.

- Antigenic differences, as measured with ferret sera, are sufficiently large (>> 4-fold HI) to warrant selection of vaccine candidates for each clade (Note: extrapolation from H1/H3)

- Information on strains outside of clades 0, 1, 2.1, 2.2, 2.3 is scarce

- Until ‘05/’06 there was little antigenic drift WITHIN clades; later years under investigation

H5 influenza map- Other considerations -

When we trust the antigen positions / antigenic relationships:

- Can we say something reasonable about the serum positions / serum (cross-) reactivity?(e.g. for vaccine evaluation)

H5 influenza - Antigenic map, up to 2005/2006 -

Antisera to classical H5 strains

Antisera to HPAI H5N1 strains

H5 antigenic maps- Rate of antigenic change (until 2005) -

Calculate, based on rate of antigenic evolution (or emergence of new clades) andbreadth of immune response induced by a particular vaccine:HOW LONG CAN WE USE THIS VACCINE?

Veterinary H5 vaccine- Analysis of serum antibodies -

Dutch zoosBirds (>3000) vaccinated with water in oil adjuvanted WIV A/Duck/Pottsdam/1402/86 (H5N2)Two s.c. shots, 6 weeks apart, dose depending on bodyweightAfter one shot: GMT 37 (95% CI 25-53), 50% >HI 40After two shots: GMT 190 (95% CI 152-236), 80% >HI 40Post-vaccination sera (28 birds, 7 orders) measured in HI against prototypes for clades:

- Classical (A/Mallard/Netherlands/3/1999)- 0 (A/Hongkong/156/1997)- 1 (A/Vietnam/1194/2004)- 2.1 (A/Indonesia/1/2005)- 2.2 (A/Turkey/Turkey/1/2005)

Philippa et al., Vaccine 25: 3800-3808 (2007).

Veterinary H5 vaccine- Analysis of serum antibodies -

H5 antigenic maps- Vaccine evaluation -

Now: homologous titer

Should evaluate:- Titer of immune response - Focus of immune response- Breadth of immune response

Good

Bad

Good

Bad

Conclusions- Antigenic cartography & antibody landscapes -

- Antigenic cartography offers visualization and quantitative analysis of antigenic differences between circulating strains; introduces agreement between labs

- At least 6 “antigenic clades” of H5 exist, probably more, some MAY be drifting?

- Cartography enables visualization and quantitative analysis of antibody responses (titer, focus, breadth), in relation to antigenic variation of H5 strains

- Antigenic cartography and antibody landscapes facilitate quantitative and qualitative comparison of data from different vaccine trials

- Antigenic cartography and antibody landscapes facilitate analysis of the effects ofpre-vaccination antibodies, and prime/boost strategies with different strains(original antigenic sin, etc.)

- Antigenic cartography may aid in H5N1 serosurveillance studies in wild birds

Acknowledgements

Department of Zoology, Cambridge University (UK) Terry Jones, Collin Russell, Eugene Skepner, Ana Mosterin, David Burke, Dan Horton, Nicola Lewis, Margaret MacKinnon, Derek SmithNational Influenza Center, Department of Virology, Erasmus Medical Center Emmie de Wit, Vincent Munster, Juthatip Keawcharoen, Bjorn Koel, Theo Bestebroer, Monique Spronken, Chantal Baas, Pascal Lexmond, Ruudvan Beek, Rob van Lavieren, Guido van de Net, Walter Beyer, Jan de Jong, Guus Rimmelzwaan, Ab OsterhausCenters for Disease Control and Prevention (USA)Alexander Klimov, Ruben Donis, Nancy CoxSt Jude Children’s Research Hospital (USA)Robert Webster, Scott Krauss, Richard WebbyIZSVe (Italy)Ilaria Capua, Maria Serena BeatoSoutheast Poultry Research Labs (USA)David Swayne, Erica SpackmanCommunity Reference Laboratory, VLA (UK)Ian Brown, Jill Banks, Budhipa ChoudhuryJapfa Comfeed (Indonesia)Teguh PrajitnoWHO, FAO, OIE, OFFLU NIVAREC