Helen Johnson specialises in the use of Artificial Intelligence (AI) methods in political decision-making, including approaches for accounting for uncertainty, reducing bias and ensuring representation.

Between 2017 and 2023 she worked as a mathematical modeller at the European Centre for Disease Prevention and Control (ECDC) in Stockholm and at the European Commission in Brussels, advising decision-makers on pandemic policy, including social distancing measures, border closures, pharmaceutical procurement and vaccine strategy. An applied mathematician, she has advanced the use of Bayesian methods for inferring the causes and determinants of health outcomes. She is committed to promoting the public and political understanding of non-linearity (why the past is not always a good indicator of the future) and dynamic systems (why some things get better and better while others get worse and worse and anticipating unintended consequences), together with their implications for policy decisions.

She holds degrees in Physics and Biomolecular Science from Imperial College and in the Control of Infectious Diseases from the London School of Hygiene & Tropical Medicine. .