Imperial College London


Faculty of MedicineSchool of Public Health

Prof of Infectious Disease & Vaccine Epidemiology



n.grassly Website




1102Building E - Sir Michael UrenWhite City Campus




Current Research Topics

1. Vaccine epidemiology

We research the epidemiology of infectious diseases and vaccines, with expertise in math modelling, statistics, clinical trial design and genomics. We are interested in how vaccine efficacy and effectiveness is measured, the impact of vaccination on disease dynamics and optimal vaccination strategies. We have over 15 years’ experience working on the epidemiology of vaccines, including those against polio, typhoid, rotavirus diarrhoea, and most recently COVID-19.

Recent publications

Williams LR, Ferguson NM, Donnelly CA, Grassly NC. 2021. Measuring vaccine efficacy against infection and disease in clinical trials: sources and magnitude of bias in COVID-19 vaccine efficacy estimates. Clinical Infectious Diseases, ISSN: 1058-4838

Cooper LV, Bandyopadhyay A, Gumede N, Mach O, Mkanda P, Ndoutabe M, Okiror S, Ramirez-Gonzalez A, Touray K, Wanyoike S, Grassly NC, Blake IM. 2021. Risk factors for spread of vaccine-derived type 2 polioviruses in Africa following global withdrawal of trivalent oral poliovirus vaccine and impact of outbreak response with monovalent vaccine: a retrospective analysis of surveillance data. Lancet Infectious Diseases. Vol:22, ISSN:1473-3099, Pages:284-294.

Grassly NC, Pons-Salort M, Parker EPK, White PJ, Ferguson NM, Ainslie K, Baguelin M, Bhatt S, Boonyasiri A, Brazeau N, Cattarino L, Coupland H, Cucunuba Z, Cuomo-Dannenburg G, Dighe A, Donnelly C, van Elsland SL, FitzJohn R, Flaxman S, Fraser K, Gaythorpe K, Green W, Hamlet A, Hinsley W, Imai N, Knock E, Laydon D, Mellan T, Mishra S, Nedjati-Gilani G, Nouvellet P, Okell L, Ragonnet-Cronin M, Thompson HA, Unwin HJT, Vollmer M, Volz E, Walters C, Wang Y, Watson OJ, Whittaker C, Whittles L, Xi X. 2020. Comparison of molecular testing strategies for COVID-19 control: a mathematical modelling study. The Lancet Infectious Diseases 20:1381-1389.

2. Disease surveillance and genomics

We research novel approaches to infectious disease surveillance, including the use of serological surveys, environmental (sewage) surveillance and next-generation (nanopore) sequencing. We have developed a novel method for poliovirus detection and sequencing, which is being investigated for its potential to accelerate poliovirus detection and outbreak response. We are also investigating environmental surveillance for typhoid and other enteric pathogens, with research partners around the world including India, Malawi, Ghana and Fiji.

Recent publications

Shaw A, Cooper L, Gumede N, Bandyopadhyay AS, Grassly NC, Blake IM. 2021. Time taken to detect and respond to polio outbreaks in Africa and the potential impact of direct molecular detection and nanopore sequencing, Journal of Infectious Diseases, ISSN:0022-1899 

Shaw AG, Troman C, Grassly N. 2020. Rapid and sensitive direct detection and identification of poliovirus from stool and environmental surveillance samples using nanopore sequencingJournal of Clinical Microbiology, Vol: 58, Pages: 1-13, ISSN: 0095-1137

Uzzell CB, Troman CM, Rigby J, Mohan VR, John J, Abraham D, Srinivasan R, Nair S, Meschke JS, Elviss N, Kang G, Feasey N, Grassly NC. 2021. Environmental surveillance for Salmonella Typhi as a tool to estimate the incidence of typhoid fever in low-income populations. medRxiv doi:10.1101/2021.05.21.21257547:2021.05.21.21257547.

3. Immune correlates of protection by vaccination

We investigate factors affecting the immune response to vaccination and immune correlates of protection (CoP) following vaccination. This work is focused particularly on the mucosal immune response to rotavirus and poliovirus vaccines and protection against challenge with live-attenuated vaccine virus.

Recent publications

Chilengi R, Simuyandi M, Chibuye M, Chirwa M, Sukwa N, Laban N, Chisenga C, Silwamba S, Grassly N, Bosomprah S 2020, A pilot study on use of live attenuated rotavirus vaccine (Rotarix (TM)) as an infection challenge model, VACCINE, Vol: 38, Pages: 7357-7362, ISSN: 0264-410X

Babji S, Manickavasagam P, Chen Y-H, Jeyavelu N, Jose NV, Praharaj I, Syed C, Kaliappan SP, John J, Giri S, Venugopal S, Kampmann B, Parker EPK, Iturriza-Gómara M, Kang G, Grassly NC, Uhlig HH, 2020, Immune predictors of oral poliovirus vaccine immunogenicity among infants in South India., NPJ Vaccines, Vol: 5

Praharaj I, Parker EPK, Giri S, Allen D, Silas S, Revathi R, Kalliappan S, John J, Prasad J, Kampmann B, Iturriza-Gómara M, Grassly N, Kang G, 2019, Influence of nonpolio enteroviruses and the bacterial gut microbiota on oral poliovirus vaccine response: A study from south India, Journal of Infectious Diseases, Vol: 219, Pages: 1178-1186, ISSN: 0022-1899


Roma Chilengi, Centre for Infectious Disease Research, Zambia (CIDRZ), Clinical trial of novel rotavirus vaccine, 720 infants, 2018

Gagandeep Kang and Jacob John, Christian Medical College, Vellore, India, various poliovirus and rotavirus vaccine clinical trials, >1400 infants, 2010

Nick Feasey, Jon Rigby, Malawi-Liverpool Wellcome Trust, Malawi

Placide Mbala, Institut National de Recherche Biomédicale, DRC

Yaw Adu-Sarkodie, Ellis Owusu-Dabo, Sampson Twumasi-Ankrah, Michael Owusu, Kwame Nkrumah University of Science and Technology, Ghana

Miren Iturriza-Gomara, PATH

Javier Martin, Manasi Majumdar, Erika Bujaki, NIBSC, UK

Merryn Voysey, Andrew Pollard, Peter Simmonds, University of Oxford

Prof Andrew Rambaut, University of Edinburgh

Cecil Czerkinsky, Nicolas Glaichenhaus, Emanuela Martinuzzi, French National Institute of Health and Medical Research