Marc Lipsitch. (2021, July 20). At the risk of boiling down too much and certainly losing some detail, one way to summarize this wonderful thread is that when we think about vaccine effectiveness, we should think of 4 key variables: 1 which vaccine, 2 age of the person, 3 how long after vax, 4 vs what outcome. [Tweet]. @mlipsitch. https://twitter.com/mlipsitch/status/1417595538632060931

Hulme, W. J., Williamson, E. J., Green, A., Bhaskaran, K., McDonald, H. I., Rentsch, C. T., Schultze, A., Tazare, J., Curtis, H. J., Walker, A. J., Tomlinson, L., Palmer, T., Horne, E., MacKenna, B., Morton, C. E., Mehrkar, A., Fisher, L., Bacon, S., Evans, D., … Goldacre, B. (2021). Comparative effectiveness of ChAdOx1 versus BNT162b2 COVID-19 vaccines in Health and Social Care workers in England: A cohort study using OpenSAFELY [Preprint]. Epidemiology. https://doi.org/10.1101/2021.10.13.21264937