Insect cell-expressed hemagglutinin with CpG oligodeoxynucleotides plus alum as an adjuvant is a potential pandemic influenza vaccine candidate

► A candidate pandemic influenza vaccine was designed in the present study. ► Recombinant HA expressed in insect cells was used as an antigen. ► CpG-ODN plus alum was used as a composite adjuvant. ► The candidate vaccine induced robust immune response in mice. ► The candidate vaccine protected the immunized mice from lethal influenza challenge.