Injectable trace minerals (ITM) administered simultaneously to novel antigens of porcine red blood cells (PRBC) affects trace mineral status, innate and humoral immune responses of weaned beef heifers. Angus heifers (n = 22; 234 ± 39 kg of BW; 225 ± 19 d of age) were stratified by BW and age, and randomly assigned to receive a 2.5-mL s.c. injection of sterile saline (SAL; 0.9% NaCl), ITM (MultiMin 90; Multimin USA, Inc. Fort Collins, CO; 60, 10, 15 and 5 mg/mL of Zn, Mn, Cu and Se), or a squalene-based oil-in-water adjuvant (ADJ; AddaVax; InvivoGen, Inc. San Diego, CA) that promotes humoral immune response. Thereafter (d 0), heifers were immunologically challenged with a 10-mL i.m. injection of PRBC solution (25% PRBC; 75% sterile PBS), allocated to drylot pens (2 pens/treatment) and limit-fed a fescue hay-based diet at 2.2% of BW for 28 d. Shrunk BW was recorded on d 0 and 28, blood samples collected on d 0, 3, 7, 15, 21 and 28, and liver samples collected on d 14. Body weight on d 28 (263, 262 and 258 ± 19 kg) and mean ADG (0.81, 0.98 and 0.96 ± 0.180 kg/d for SAL, MM and ADJ heifers) did not differ among treatments (P ≥ 0.72). But, treatment effects were detected (P ≤ 0.05) for concentrations of liver Se, plasma ceruloplasmin (Cp) and serum PRBC titers. Liver Se was greater for MM vs. ADJ and SAL heifers (2.21, 1.36 and 1.45 ± 0.177 mg/kg, respectively), whereas plasma Cp was greater for ADJ vs. SAL (26 vs. 20 ± 1.6 mg/dL; P = 0.02), and intermediate for ITM heifers (23 ± 1.6 mg/dL; P ≥ 0.17). Likewise, serum PRBC titers were greater for ADJ vs. SAL (1.6 vs. 0.7 ± 0.28 log 2 base; P = 0.02), and intermediate for ITM heifers (1.1 ± 0.28 log 2 base; P ≥ 0.13). Treatment x time effect was detected for plasma haptoglobin (Hp) concentrations (P < 0.0001), which did not differ from d 0 to 28 (P ≥ 0.18), but were greater for ADJ vs. SAL and ITM heifers on d 3 (0.71, 0.05 and 0.07 ± 0.032 mg/mL). Hence, although injectable trace mineral injection enhanced liver Se concentrations, the magnitude of the innate and humoral immune responses to novel antigen were less compared with a water-in-oil adjuvant.