LAUSR

Correspondence to Professor Jonathan Wolff; jonathan. wolff@ bsg. ox. ac. uk © Author(s) (or their employer(s)) 2021. Reuse permitted under CC BYNC. No commercial reuse. See rights and permissions. Published by BMJ. INTRODUCTION As a growing number of vaccines for COVID-19 gain emergency use designation, including emergency use authorisation and conditional marketing authorisation under different jurisdictions, the WHO Strategic Advisory Group of Experts on Immunization (SAGE) has issued a number of guidance papers for their recommended use. The overall framework is set out in an Evidence Framework document, and has currently been applied to several vaccines. The framework is also guided by the SAGE Values Framework and prioritisation guidelines. The overarching aim of the Evidence Framework is to make recommendations based on the principles of evidencebased medicine. COVID-19 immunisation is a very fastmoving area, with a highly varied landscape, as new vaccines become available, yet supply lags a long way behind global demand. The emergence of new variants adds further complexity. Each country is in its own unique circumstances and while scientific knowledge is increasing day by day, there are many scientific uncertainties, and few easy decisions. Even taking current scientific knowledge into account, very often decisions involve tradeoffs with health and nonhealth risks and benefits on both sides, calling for judgements to be made by policymakers. It is not the aim of this paper to provide a solution to the very difficult questions different countries face, but to provide guidance on the considerations that ethically should be taken into account in making such decisions about whether to proceed with different modalities. Summary box