Sanofi Pasteur announced that its dengue vaccine, Dengvaxia, may lead to more severe cases of dengue fever in some people — a warning it relayed after the vaccine was already administered to more than 700,000 children in the Philippines. Those at risk, according to Sanofi, are people who have not been previously infected by dengue virus.
Their new analysis that evaluated long-term safety and efficacy of the vaccine revealed that “in the longer term, more cases of severe disease could occur following vaccination upon a subsequent dengue infection.”1
As a result, the Philippines has launched an investigation and convened an expert panel to figure out what to do next. Health Secretary Francisco Duque said in a news release,
“The safety of the children vaccinated is paramount, and the Health Department will need to do surveillance of those given Dengvaxia with no prior infection. It’s really a big task.”2
Nearly 4 billion people across 128 countries are at risk of infection with dengue, a viral disease spread by mosquitoes.3
Symptoms of dengue fever range from mild (or none at all) to high fever along with headache, body pain, nausea, vomiting and pain behind the eyes, with most people recovering within a week.4 A severe form of the disease, known as dengue hemorrhagic fever or severe dengue, however, is life-threatening and can lead to difficulty breathing, circulatory system failure and death. It’s this severe form of dengue that Dengvaxia vaccine may increase risks for in people who have not previously been infected with dengue.
Sanofi Claimed Long-Term Safety Studies Were Completed, Now Recommends Against Vaccination in Some
In 2015, the Philippines’ Food and Drug Administration approved Dengvaxia, the first dengue vaccine in Asia, manufactured by Sanofi Pasteur. The vaccine was intended to prevent all four dengue types in individuals from 9 to 45 years of age living in endemic areas.5 At the time, Sanofi claimed studies had been conducted “affirming the vaccine’s consistent efficacy and longer-term safety profile in a study population 9 to16 years of age.”6
The new analysis, however, is based on up to six years of clinical data evaluating the long-term safety and efficacy of Dengvaxia in those who have been infected with dengue and those who have not.
» Lees verder