Vi polysaccharide vaccine

The Vi polysaccharide vaccine is a specialized shot that helps protect against typhoid fever, a serious illness caused by the bacteria Salmonella Typhi. It contains a purified sugar-like substance called Vi antigen, taken from the bacteria's surface. When you receive the vaccine, your immune system learns to recognize this component and develops protection against the bacteria. It’s typically administered as a single injection and provides several years of immunity. The vaccine is especially useful for travelers to areas where typhoid is common and for populations at higher risk, helping prevent outbreaks and reduce illness severity.