approved for use in Singapore. It was already in use in nine other countries including, Indonesia, Thailand, The Philippines, Mexico and Brazil.
A total of 24 clinical studies with more than 41,000 subjects were conducted by Sanofi. The 24 studies reviewed include two major clinical studies conducted in Latin America and Asia on individuals between two and 16 years old, and 22 supportive studies assessing the anti-body levels in individuals following vaccination.
Overall the vaccine was effective in reducing dengue illness by 60 percent and reducing severe dengue illness by 84 percent.
The vaccine was also most effective in those who already have baseline immunity due to a previous dengue infection. It was 81 per cent effective in those who had dengue previously, compared to 38 per cent in those who had not been infected before.
However, the studies also showed that the vaccine is less effective against the DENV-1 and DENV-2 strains of Dengue.
But, the study conducted by the researchers from Johns Hopkins Bloomberg school of Public Health, Imperial College of London and the University of Florida found that Sanofi’s Dengvaxia could do more harm than good in certain settings. The reason they says is that Dengue is different from most infectious diseases, in that a person’s second infection is typically much more serious than the first.
However in vaccinated children between nine and 11 years old, the studies showed a 30 per cent increase in risk of hospitalization and three times the risk of severe dengue.