The Salk Vaccine is a vaccine developed by Dr. Jonas Salk in the early 1950s to prevent polio, a viral disease that can cause paralysis. It is an inactivated poliovirus vaccine (IPV), meaning it uses killed virus particles to stimulate the immune system without causing the disease. The vaccine was first tested in 1954 and became widely available in 1955, significantly reducing polio cases in many countries. The introduction of the Salk Vaccine marked a major milestone in public health, leading to mass immunization campaigns. Its success paved the way for further research and development of vaccines, including the Sabin Vaccine, which is an oral vaccine that uses live attenuated virus. Together, these vaccines have played a crucial role in the near-eradication of polio worldwide.