The first successful polio vaccine was developed by Jonas Salk in the early 1950s. This inactivated polio vaccine (IPV) was created using killed poliovirus, which helped the immune system recognize and fight the virus without causing the disease. Salk's vaccine was tested extensively and proved to be safe and effective. In 1955, the vaccine was announced to the public, leading to a significant decline in polio cases. The widespread vaccination campaigns that followed helped protect millions of children from this debilitating disease, marking a major milestone in public health and paving the way for further advancements in vaccines.