What is the primary use of the Vivotif vaccine?

The primary use of the Vivotif vaccine is to prevent typhoid fever. Typhoid fever is an infectious disease caused by the bacterium Salmonella typhi, which is often transmitted through contaminated food or water. Vaccination with Vivotif provides important protection in areas where typhoid fever is endemic or in situations where individuals may be exposed to the bacteria, such as during travel.

The Vivotif vaccine itself is a live attenuated vaccine, meaning it contains a weakened form of the bacterium that stimulates an immune response without causing the disease. This immune response helps the body recognize and combat the bacterium if exposure occurs in the future.

The other options pertain to different vaccines and diseases. For instance, Japanese encephalitis is prevented by a different vaccine, shingles is addressed by the herpes zoster vaccine, and hepatitis A has its own specific vaccine for prevention. Each of these vaccines is designed for a particular infectious disease, emphasizing the importance of proper vaccination according to the risk factors and geographic exposures relevant to the individual.