Robust Spike-Specific CD4 + and CD8 + T Cell Responses in SARS-CoV-2 Vaccinated Hematopoietic Cell Transplantation Recipients: A Prospective, Cohort Study Lorenzo Federico1, 2* , Tor H. Tvedt1 , Murat Gainullin1, 2 , Julie R. Osen1, 2, Viktoriia Chaban1, 2, Katrine P. Lund1, 2, Lisa Tietze1, 2, Trung T. Tran1, 2, Fridtjof Lund-Johansen1, 2 , Hassen Kared1, 2 , Andreas Lind1, John T. Vaage2 , Richard Stratford3, Simen Tennøe3, Brandon Malone3 , Trevor Clancy3 , Anders E.