Dr Munir Iqbal (DVM, M Phil, PhD)
Head of Avian Influenza Group
Avian Viral Diseases Programme, The Pirbright Institute
Compton Laboratory, Newbury, Berks, RG20 7NN, UK
munir.iqbal@pirbright.ac.uk
Development of novel viral vector-based vaccines and aptamer-based rapid diagnostics for
influenza viruses
Munir Iqbal1, Yongqing Li1, Thao Le2, Beata Adamiak1, Kolli Reddy1, Yashar Sadigh1, Jean-Remy
Sadeyen1, Sanjiv Sharma2, Ian H. Brown3, John W McCauley4, Venugopal Nair1, Anthony EG
Cass2.
1
Avian Viral Diseases Programme, The Pirbright Institute, Compton, Newbury, Berkshire RG20
7NN, UK.
2
Department of Chemistry and Institute of Biomedical Engineering, Imperial College, London SW7
2AZ, UK
3
Animal and Plant Health Agency Agency, Weybridge, Addlestone, Surrey KT15 3NB UK
4
Division of Virology, MRC National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
Avian Influenza viruses (AIV) seriously affect poultry production, human health, food security,
trade, economy and the livelihood of millions of people around the globe. The effective control of
AIV infection in poultry is complex and requires improvement in vaccines and diagnostic tools.
Considering these needs, we have developed novel herpesvirus of turkeys (HVT)- based vector
vaccines and aptamer-based simple rapid diagnostic tests to better control AIV infection in poultry.
Recombinant HVT- AIV vaccine constructs expressing haemagglutinin (HA) antigens of H5, H7 or
H9 subtypes of AIV were generated using reverse genetics of an infectious bacterial artificial
chromosome (BAC) clone of HVT. Immunization of one-day-old chicks with these vaccines induced
HA-specific antibodies and protected chickens challenged with highly pathogenic AIV from viral
shedding, clinical disease and death. These recombinant HVT- AIV vaccines also retained their
inherent properties affording complete protection against highly virulent Marek disease virus.
Additionally, the vaccines allowed differentiation between AIV infected and vaccinated animals
(DIVA).
Aptamers-based diagnostic assays were developed by selecting synthetic DNA and RNA aptamers
that specifically and selectively bound to selected AIV subtypes (H5, H9 and H7) using SELEX
(systematic evolution of ligands by exponential enrichment) procedures. The selected aptamers
were labelled with gold nanoparticles followed by assembling onto viral particles forming a gold
nanoshell (AuNS)-like structures around the virus envelope. These assembled (virus-aptamersgold nanoparticles) structures can be sedimented with either a portable mini-centrifuge or
domestic electric whisk. The colouration of gold nanoparticles to the virus pellet provides a simple
visual detection of virus presence in a sample.
These next generations of vaccines and diagnostic tools have the potential to transform AIV control
strategies, providing substantial economic, public health, environmental and social benefits at a
global scale.