DNA vaccines work by injecting genetically engineered DNA that causes host cells to produce antigens, which stimulate the immune system. They have several advantages over traditional vaccines, including lower risk and ability to induce both antibody and T cell responses. DNA vaccines are made by inserting antigen-encoding genes into bacterial plasmids, amplifying the plasmids in bacteria, purifying the DNA, and then injecting it intramuscularly or using a gene gun. The DNA is taken up by host cells and expressed as antigens, which are processed and presented to induce cytotoxic T cells and antibody production against the target pathogen. Future improvements may enhance DNA uptake and expression to improve immune responses.