Figure 4.

Cobalt nanomaterials can be used for vaccine delivery. Vaccines contain weakened or inactivated parts of specific organisms (antigen) that can trigger an immune response in the body, producing a small amount of antibodies and memory T cells and memory B cells. When the body is exposed to the same antigen again, these two cells quickly proliferate and differentiate to produce effector T cells and effector B cells (plasma cells) to quickly remove the antigen and then: plasma cells produce antibodies and neutralize antigen binding. Effector T cells and the target cells are in close contact, making the target cells lysis and death.