human
How can I make a natural typhoid vaccine?
assistant
Typhoid is caused by a bacterium called Salmonella typhi. You could try making a vaccine using the bacteria itself, but it would probably be pretty weak. A better option might be to use the polysaccharides from S. typhi as antigens in a vaccine. These are molecules that the immune system recognizes and responds to. They’re found on the surface of the bacteria, so they’re easy to extract and purify.