Focus: Developing and evaluating statistical methods that provide reliable vaccine effectiveness estimates while accounting for biases in observational study designs.
Waning Protection
Waning Vaccine Effectiveness
The WAVE project develops and evaluates statistical methods for assessing how vaccine-induced protection changes over time. Key objectives include distinguishing true immunity decline from apparent waning due to changes in pathogen or population, identifying individual determinants of protection decline, and applying methods across multiple vaccines — including pertussis, influenza, COVID-19, and rotavirus.
Haber, M., et al. Comparing statistical methods for detecting and estimating waning efficacy of rotavirus vaccines in developing countries. Hum Vaccin Immunother. 2021. Read paper →
Chen, D., Cowling, B. J., Ainslie, K. E. C., et al. Association of COVID-19 vaccination with duration of hospitalisation in older adults in Hong Kong. Vaccine 2024. Read paper →
Influenza
Bias in Observational Studies
Statistical and modelling approaches to identify and account for bias in observational VE studies. This includes evaluating sources of bias in common study designs, developing methods to estimate VE against both susceptibility and onward transmission, and extending this work from influenza to COVID-19 contexts.
Ainslie, K. E. C., et al. A Dynamic Model for Evaluation of the Bias of Influenza Vaccine Effectiveness Estimates. Am J Epidemiol. 2018. Read paper →
Ainslie, K. E. C., et al. Challenges in estimating influenza vaccine effectiveness. Expert Rev Vaccines. 2019. Read paper →
Ainslie, K. E. C., et al. Maximum likelihood estimation of influenza vaccine effectiveness against transmission. Stat Med. 2017. Read paper →
Ainslie, K. E. C., Haber, M., Orenstein, W. A. Bias of influenza vaccine effectiveness estimates from test-negative studies conducted during multiple seasons. Vaccine 2019. Read paper →
Ainslie, K. E. C., Shi, M., Haber, M., Orenstein, W. A. On the bias of estimates of influenza vaccine effectiveness from test-negative studies. Vaccine 2017. Read paper →
Shi, M., An, Q., Ainslie, K. E. C., et al. A comparison of the test-negative and the traditional case-control study designs for estimation of influenza vaccine effectiveness. BMC Infect Dis. 2017. Read paper →
Sullivan, S. G., Khvorov, A., Huang, X., Ainslie, K. E. C., et al. The need for a clinical case definition in test-negative design studies estimating vaccine effectiveness. npj Vaccines 2023. Read paper →
Tsang, T. K., et al. Prior infections and effectiveness of SARS-CoV-2 vaccine in test-negative studies. Am J Epidemiol. 2024. Read paper →
Repeat Vaccination Effects
Individual-based stochastic modelling to investigate optimal influenza vaccination strategies in children, accounting for prior vaccination history, antigenic dynamics, and long-term immune imprinting.
Ainslie, K. E. C. and Riley, S. Is annual vaccination best? A modelling study of influenza vaccination strategies in children. Vaccine 2022. Read paper →
Related software: morevac