So incredibly sorry to hear of Helen’s sudden passing. I greatly valued her work on HAIRS risk assessments, especially on SARS-CoV-2 and animals, and had heard her name many times before I finally had the chance to meet her. In my short time working with her, I was very impressed with what a wealth of knowledge she was and also how she was such an open and kind person. I was very much looking forward to continuing to learn from her. My sincere condolences to her family, friends, and colleagues.