Typhoid vaccines - Newer developments

Abstract

Typhoid fever continues to be a major public health problem in the developing world. Antibiotic therapy has been the main stay of treating typhoid fever for decades .The emergence of multi drug resistant typhoid strains in the last 3 decades has been a major problem in tackling this scourge. Children constitute almost half of the total number of cases of multi drug resistant typhoid fever and are more vulnerable to its complications. In the absence of proper sanitation, vaccination is the only viable preventive option to control this disease. The first typhoid vaccine was introduced more than a century ago. It was a killed whole cell vaccine, found to be effective, but it fell into disrepute because of adverse effects and discarded. Developments in typhoid vaccine subsequently brought forth the Ty 21a oral typhoid vaccine and then the Vi capsular polysaccharide vaccine. These two vaccines showed limited efficacy with a better safety profile but were not effective in children less than 5 years of age. Development of conjugate polysaccharide typhoid vaccines has been the latest achievement. These and other oral typhoid vaccines under development are the typhoid vaccines of the future.