A “ground breaking” typhoid vaccine has reduced cases of the bacterial disease by more than 80 percent in a trial involving 20,000 children in Nepal.
It is the first time the inoculation, typhoid conjugate vaccine (TCV), has been tested in the field but experts say the “exciting” results could be a turning point in efforts to combat drug-resistant typhoid infections.
The highly contagious disease, caused by Salmonella Typhi bacteria, spreads rapidly in areas with poor sanitation and dirty drinking water and is a leading cause of fever among children. Each year, nearly 12 million people are infected and between 128,000 and 160,000 die.
Salmonella Typhi is increasingly resistant to the antibiotics typically used to treat typhoid, so experts say that new vaccines are vital to prevent infections occurring in the first place. Pakistan is currently in the midst of an antibiotic-resistant typhoid outbreak.
There are two existing typhoid vaccines. One comes in a capsule that is too large for younger children to swallow, so it is for youngsters over age 6. The other, delivered as an injection, doesn’t work in children under age 2.
The new test, reported in the New England Journal of Medicine, involved children as young as 9 months. They will be followed for another year in an attempt to determine how long the vaccine protects against typhoid. Further two-year field tests are also underway in Bangladesh and Africa to gauge its effectiveness there.
TCV has already been endorsed by the World Health Organization’s Global Advisory Committee on Vaccine Safety based in part on earlier tests at Oxford.