The adaptive immune response is a specialized defense mechanism that the body uses to recognize and remember specific pathogens, such as viruses and bacteria. This response involves the activation of T cells and B cells, which are types of white blood cells. When a pathogen invades, these cells identify it and mount a targeted attack, producing antibodies that neutralize the threat. Once the infection is cleared, some B cells and T cells remain in the body as memory cells. This allows the immune system to respond more quickly and effectively if the same pathogen invades again in the future. This memory aspect is the basis for how vaccines work, providing long-lasting protection against diseases.