Meet Our Team
Dr. Charles Whittaker, PhD
Assistant Professor
Department of Infectious Diseases and Vaccinology
School of Public Health
University of California, Berkeley
Jacob Stapley, PhD
Postdoctoral Research Associate
Department of Infectious Diseases and Vaccinology
School of Public Health
University of California, Berkeley
Geetha Jeyapragasan, M.Sc.
PhD Student
Computational Precision Health Graduate Group
School of Public Health
University of California, Berkeley
Want to join us?
PETAL is always looking for talented and curious scientists that share our mission. See our Join Us section for further details!
Dr. Charles Whittaker, PhD
Assistant Professor
Department of Infectious Diseases and Vaccinology
School of Public Health
University of California, Berkeley
Dr Charles Whittaker is an Assistant Professor of Infectious Diseases & Vaccinology at the University of California, Berkeley, where he directs the Pandemic and Epidemic Threat Analytics Lab (PETAL). His group integrates infectious-disease modelling, viral phylodynamics and machine learning to uncover new insights into how pathogens spread through populations and to enhance preparedness and response strategies for public-health emergencies. Before joining Berkeley, Charles was a Sir Henry Wellcome Research Fellow at the MRC Centre for Global Infectious Disease Analysis, Imperial College London, where he co-led a team providing global analytical support to countries around the world during the COVID-19 pandemic. He is also a field epidemiologist, and previously served with both the UK’s Public Health Rapid Support Team and the World Health Organization, the latter including deployment to the 2018–2020 North Kivu Ebola outbreak in the Democratic Republic of the Congo, where he provided real-time modelling support for field operations. His research is built on collaborative partnerships with public-health agencies and scientists across Africa, the Americas, Europe and Asia, and is regularly translated into decision-making tools that guide regional and international health policy.
Jacob Stapley, PhD
Postdoctoral Research Associate
Department of Infectious Diseases and Vaccinology
School of Public Health
University of California, Berkeley
Jacob is a postdoctoral scholar in the PETAL Lab at UC Berkeley, where he develops and applies infectious disease transmission models to assess the impact of public health interventions. His research contributes to pandemic preparedness and the elimination of diseases that disproportionately affect vulnerable populations around the world. He completed his PhD in infectious disease epidemiology at Imperial College London, where he used individual-based stochastic models to investigate the dynamics of onchocerciasis transmission and elimination in sub-Saharan Africa. This work included field collaboration with CDC in rural Ghana, and the coordination of a multi-country research network to consolidate unused datasets. Prior to his PhD, he earned Master’s degrees from the University of Warwick and Imperial College London, building a broad foundation in biomedical science and quantitative research. He also worked in the pharmaceutical industry, where he supported evidence-based claims for consumer healthcare products. Outside of research, he is an aviation enthusiast and avid traveller, having visited over 100 countries.
Geetha Jeyapragasan
PhD Student
Computational Precision Health Graduate Group
School of Public Health
University of California, Berkeley
Geetha Jeyapragasan is a PhD student in the Computational Precision Health program at UC Berkeley. Her research interests center around improving public health decision-making for pandemic preparedness and biosecurity, with particular interest in infectious disease modeling, health economic evaluation, and the governance of dual-use and emerging life sciences research. She is currently a Research Fellow at SecureBio, where she works on developing technical biosecurity evaluations to assess the risks of AI systems in biological applications to inform the responsible development and deployment, and previously worked with the Stanford Existential Risks Initiative (SERI) in the Bio Policy Lab on life sciences risk governance.
Geetha earned her M.Sc. from the MIT Media Lab, where her thesis was a quantitative risk-benefit assessment of pandemic virus identification research under the supervision of Dr. Kevin Esvelt in the Sculpting Evolution Group. She completed her Honours B.Sc. in Integrated Science with a concentration in Mathematics and Statistics at McMaster University. Her work aims to leverage computational approaches to strengthen pandemic surveillance systems and outbreak response strategies, particularly in resource-limited settings, and to inform evidence-based approaches to preventing and mitigating emerging biological threats.