In a murine model of invasive pulmonary aspergillosis, dendritic cells (DCs) pulsed with Aspergillus antigens induced the activation of CD4+ Th1 cells capable of conferring resistance to the infection. Here we show that the combined, local delivery of unmethylated CpG oligodeoxynucleotides (ODNs) and the Asp f 16 Aspergillus allergen resulted in the functional maturation and activation of airway DCs capable of inducing Th1 priming and resistance to the fungus. Therefore, ODNs act as a potent adjuvant for the vaccine-induced protection against the fungus by promoting dominant Th1 response to Aspergillus antigens and allergens. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.