Immunogenicity and efficacy of one and two doses of Ad26.COV2.S COVID vaccine in adult and aged nonhuman primates

Laura Solforosi, Harmjan Kuipers, Mandy Jongeneelen, Sietske K. Rosendahl Huber, Joan E.M. van der Lubbe, Liesbeth Dekking, Dominika N. Czapska-Casey, Ana Izquierdo Gil , Miranda R.M. Baert, Joke Drijver, Joost Vaneman, Ella van Huizen, Ying Choi, Jessica Vreugdenhil, Sanne Kroos, Adriaan H. de Wilde, Eleni Kourkouta, Jerome Custers, Remko van der Vlugt, Daniel Veldman, Jeroen Huizingh, Krisztian Kaszas, Tim J. Dalebout, Sebenzile K. Myeni, Marjolein Kikkert, Eric J. Snijder, Dan H. Barouch, Kinga P. Böszörményi, Marieke A. Stammes, Ivanela Kondova, Ernst J. Verschoor, Babs E. Verstrepen, Gerrit Koopman, Petra Mooij, Willy M.J.M. Bogers, Marjolein van Heerden, Leacky Muchene, Jeroen T.B.M. Tolboom, Ramon Roozendaal, Boerries Brandenburg, Hanneke Schuitemaker, Frank Wegmann, Roland C. Zahn

Safe and effective coronavirus disease–19 (COVID-19) vaccines are urgently needed to control the ongoing pandemic. While single-dose vaccine regimens would provide multiple advantages, two doses may improve the magnitude and durability of immunity and protective efficacy. We assessed one- and two-dose regimens of the Ad26.COV2.S vaccine, also known as the Janssen vaccine, in adult and aged nonhuman primates. A two-dose regimen induced higher peak binding and neutralizing antibody responses compared with a single dose. In one-dose regimens, neutralizing antibody responses were stable for at least 14 wk, providing an early indication of durability. Aged vaccinated animals showed near complete lower and substantial upper respiratory tract protection for one dose and two dose regimens (Figure).

Published April 2021 in Journal of Experimental Medicine (JEM)