Platform Randomised trial of INterventions against COVID-19 In older peoPLE (PRINCIPLE): protocol for a randomised, controlled, open-label, adaptive platform, trial of community tr... oleh Jienchi Dorward, Susan Hopkins, Gail Hayward, Ly-Mee Yu, Oliver van Hecke, Julie Allen, Emma Ogburn, Heather Rutter, Oghenekome Gbinigie, Sharon Tonner, Aleksandra Borek, Philip H Evans, Martin Llewelyn, Benjamin R Saville, Nicholas Berry, Hannah Swayze, David Judge, Jenna Grabey, Nicholas P B Thomas, Monique I Andersson, Mahendra Patel