If your son has typhoid fever, therapy prescribed is appropriate. The need for vitamin B complex is superfluous.
After an episode of confirmed typhoid fever, the child is protected from the usual doses of infection for about 2-3 years or so. However, excessive inoculum of infection from food sources can overcome this immunity. Thus, typhoid can recur in future, either after years or if the infective dose in food is very high. The child does not need any typhoid vaccination for a period of about 2-3 years if he had confirmed typhoid fever. Rarely, some subjects can become carriers after antibiotic dose (for example cefixime); it is difficult to predict this possibility in an individual child.