Infection is the most common cause of mortality in early life, and immunization is the most promising biomedical intervention to reduce this burden. However, newborns fail to respond optimally to most vaccines. Adjuvantation is a key approach to enhancing vaccine immunogenicity, but responses of human newborn leukocytes to most candidate adjuvants, including most TLR agonists, are functionally distinct. Herein, we demonstrate that 3M-052 is a locally acting lipidated imidazoquinoline TLR7/8 agonist adjuvant in mice, which, when properly formulated, can induce robust Th1 cytokine production by human newborn leukocytes in vitro, both alone and in synergy with the alum-adjuvanted pneumococcal conjugate vaccine 13 (PCV13). When admixed with PCV13 and administered i.m. on the first day of life to rhesus macaques, 3M-052 dramatically enhanced generation of Th1 CRM-197–specific neonatal CD4+ cells, activation of newborn and infant
David J. Dowling, Simon D. van Haren, Annette Scheid, Ilana Bergelson, Dhohyung Kim, Christy J. Mancuso, Willemina Foppen, Al Ozonoff, Lynn Fresh, Terese B. Theriot, Andrew A. Lackner, Raina N. Fichorova, Dmitri Smirnov, John P. Vasilakos, Joe M. Beaurline, Mark A. Tomai, Cecily C. Midkiff, Xavier Alvarez, James L. Blanchard, Margaret H. Gilbert, Pyone Pyone Aye, Ofer Levy
(PCV13 + 3M-052) activates both Th17 and Th1 CRM-197–specific CD4+ cells.