Vaccines train the immune system to recognize and fight harmful pathogens. Most vaccines introduce a harmless version of the virus or bacteria, prompting the body to produce antibodies. (22). These antibodies stay in the system, ready to respond quickly if the real threat appears.

Scientists often use weakened or inactive forms of the virus to trigger this response. (23). Some newer vaccines use genetic instructions to help cells build a harmless protein found on the virus. This method has proven effective in recent outbreaks. (24). For example, mRNA vaccines became widely known during the COVID-19 pandemic.

Developing a vaccine involves multiple stages: lab research, animal testing, and human trials. (25). Each phase must follow strict safety protocols and be approved by health authorities. Once approved, vaccines are distributed through public health systems. (26).