Vaccines are among the most important medical discoveries that have protected humanity from many infectious diseases. With the rapid development in immunology and biotechnology, modern vaccines have been developed using advanced technologies aimed at increasing effectiveness and reducing side effects. Traditionally, vaccines were produced using weakened or inactivated viruses and bacteria. Although these methods were effective, they required long development and testing periods. Modern vaccine technologies, however, utilize genetic and molecular approaches to stimulate the immune system more efficiently. One of the most important modern technologies is messenger RNA (mRNA) vaccines. These vaccines work by introducing a small piece of genetic code from the virus into human cells. The cells then produce a viral protein that triggers the immune system to produce antibodies and immune cells capable of recognizing and fighting the real virus in the future. Another important approach is viral vector vaccines, which use harmless viruses to deliver genetic material encoding viral antigens into human cells. This method can induce a strong immune response without causing disease. Advances in genetic engineering, bioinformatics, and artificial intelligence have also accelerated vaccine development. These tools allow scientists to identify the most effective viral components for vaccine design. This was clearly demonstrated during the COVID-19 pandemic, when vaccines were developed in record time. In the future, researchers expect the development of personalized vaccines based on genetic characteristics, as well as multivalent vaccines capable of protecting against several diseases simultaneously. Al-Mustaqbal University – the first university in Iraq.