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Department of Veterinary Medicine

Cambridge Veterinary School

We have two main research interests, Equine Influenza virus (EIV) and Equine herpesvirus 1 (EHV-1).


I am the principal investigator on the Horserace betting levy board (HBLB) funded Equine Influenza Surveillance Programme. Equine influenza is the major endemic infectious disease threat to the UK racing Thoroughbred. Serious outbreaks can cause cancellation of events and lead to movement restrictions, as demonstrated during the extensive outbreaks of 2019. The best way to protect against infection is to vaccinate horses regularly. However, EIV undergoes the process of antigenic drift, gradually acquiring mutations in the surface proteins that eventually lead to immune escape. It is therefore important that vaccines are updated to represent circulating strains. Surveillance data for equine influenza viruses are collected by a number of international laboratories and reviewed each year by the Expert Surveillance Panel, which makes recommendations for strains that are suitable for use in vaccines. These recommendations are ratified by the World Organisation for Animal Health (OIE) and are recognised internationally. In order to update vaccines, we need to know how the virus is changing and this programme collects essential data regarding the genetic and antigenic changes occurring in field strains of EIV. Viruses are isolated from nasal swab samples from horses, sent in for diagnostic testing from clinical cases or in-contacts. Viruses are then subjected to detailed characterisation, both genetically and antigenically, comparing them against the current OIE-recommended vaccine strains.

In parallel, I am principal investigator working on the EHV-1 vaccine development programme, funded by the Alborada Trust and the EBM charitable Trust. EHV-1 infection in the horse can result in respiratory disease, abortions, neonatal death, and neurological disease (also known as equine herpesvirus myeloencephalopathy (EHM)). Outbreaks on stud farms in unvaccinated pregnant mares can lead to extremely high rates of late gestation abortion, or so-called abortion storms. Commercially available vaccines have been shown to induce high levels of virus-neutralising antibody and are able to reduce the extent of virus shedding of EHV-1 from infected horses, however they offer poor protection against abortion and none are licenced to protect against EHM. This was highlighted by the abortion storm recorded in Hertfordshire in 2016 and the later cases of neurological disease that occurred in Valencia in 2021, both in fully vaccinated animals.


Key publications: 

T.H. Benedyk, J. Muenzner, V. Connor, Y. Han, K. Brown, K.J. Wijesinghe, Y. Zhuang, S. Colaco, G.A. Stoll, O.S. Tutt, S. Svobodova, D.I. Svergun, N.A. Bryant, J.E. Deane, A.E. Firth, C.M. Jeffries, C.M. Crump, S.C. Graham (2021) pUL21 is a viral phosphatase adaptor that promotes herpes simplex virus replication and spread. PLoS Pathog. 17(8):e1009824. doi: 10.1371/journal.ppat.1009824.

D. Gatherer, D.P. Depledge, C.A. Hartley, M.L. Szpara, P.K. Vaz, M. Benkő, C.R. Brandt, N.A. Bryant, A. Dastjerdi, A. Doszpoly, U.A. Gompels, N. Inoue, K.W. Jarosinski, R. Kaul, V. Lacoste, P. Norberg, F.C. Origgi, R.J. Orton, P. E.Pellett, D.S. Schmid, S.J. Spatz, J.P. Stewart, J. Trimpert, T.B Waltzek, A.J. Davison. ICTV Virus Taxonomy Profile: Herpesviridae. J Gen Virol. 2021 Oct;102(10):001673. doi: 10.1099/jgv.0.001673.

J.H. Kydd, D. Hannant, R.S. Robinson, N. Bryant, N. Osterrieder (2020) Vaccination of foals with a modified live, equid herpesvirus-1 gM deletion mutant (RacHΔgM) confers partial protection against infection. Vaccine, 38, 388-398.

N.A. Bryant, G. Wilkie, C.A. Russell, L. Compston, D. Grafham, L. Clissold, K. McLay, L. Medcalf, R. Newton, A. J. Davison, D.M. Elton (2018) Genetic Diversity of Equine Herpesvirus 1 Isolated from Neurological, Abortigenic and Respiratory Disease Outbreaks. Transboundary and Emerging Diseases, 65, 817-832

G. Renaud, B. Petersen, A. Seguin-Orlando, M.F. Bertelsen, A. Waller, R. Newton, R. Paillot, N. Bryant, M. Vaudin, P. Librado, L. Orlando (2018) Improved de novo genomic assembly for the domestic donkey. Science Advances, 4, 4, doi: 10.1126/sciadv.aaq0392.

A. Rash, R. Morton, A. Woodward, O. Maes, J. McCauley, N. Bryant, D. Elton (2017) Evolution and Divergence of H3N8 Equine Influenza Viruses Circulating in the United Kingdom from 2013 to 2015. Pathogens, 8, 6, doi: 10.3390/pathogens6010006.

A. Woodward, A.S. Rash, E. Medcalf, N.A. Bryant and D.M. Elton (2015) Using epidemics to map H3 equine influenza virus determinants of antigenicity. Virology, 481, 187-198

A.L. Woodward, A.S. Rash, D. Blinman, S. Bowman, T.M. Chambers, J.M. Daly, A. Damiani, S. Joseph, N. Lewis, J.W. McCauley, L. Medcalf, J. Mumford, J.R. Newton, A. Tiwari, N.A. Bryant, D.M Elton (2014) Development of a surveillance scheme for equine influenza in the UK and characterisation of viruses isolated in Europe, Dubai and the USA from 2010-2012. Veterinary Microbiology, 169, 113-127.

C. Mavian, A. López-Bueno, N.A. Bryant, K. Seeger, M.A. Quail, D. Harris, B. Barrell, A. Alcami (2014) The genome sequence of ectromelia virus Naval and Cornell isolates from outbreaks in North America. Virology, 462-463C, 218-226.

Senior Research Associate in Virology

Contact Details

Email address: 
+44 (0)1223 337628
Available for consultancy


Collaborator profiles: 
Alborada Research Fund
Horserace Betting Levy Board