Experts are advising caution of the use of Sanofi’s dengue vaccine, at least for now. The vaccine, which has been in the works for some time could be putting people, especially children, at a heightened risk of severe disease.
Sanofi recently changed the warnings on the label of their vaccine, Dengvaxia, even though experts from the World Health Organization (WHO) had told them a year previously that the vaccine had safety risks and should only be used in people who have had a previous dengue infection.
Based on six-years of clinical data, the analysis from Sanofi that evaluated the long-term safety and efficacy of Dengvaxia in people who had been infected with dengue previously and with those who had not confirmed that it should only be used in people who had a previous infection and over the age of 9 in dengue-infested regions. The age recommendation coming from surveillance data which indicated that 70-90 per cent of people will have been exposed to dengue by the time they reach adolescence.
“These findings highlight the complex nature of dengue infection,” says Dr. Su-Peing Ng, global medical head, Sanofi Pasteur. “We are working with health authorities to ensure that prescribers, vaccinators, and patients are fully informed of the new findings, with the goal of enhancing the impact of Dengvaxia in dengue-endemic countries.”
Dengue, a mosquito-borne viral disease is painful and debilitating, for which there is no treatment. Approximately 4 billion people are at risk of dengue fever. It hits hardest in rainy seasons around tropical areas and can be lethal. There are five strains of the virus, but only one will provide the infected with anti-bodies for lifelong immunity. The other strains will, unfortunately, have a short-term immunity, leaving the infected with the potential of subsequent infections that can cause severe complications.
The vaccine, which can act as a first infection to those who have not been infected with dengue before, has been approved in 19 countries and launched in 11. The Philippines, who had invested a hefty sum into the dengue vaccination program recently pulled the vaccine off the shelves after Sanofi’s statement that the vaccine could cause “severe disease” was released. The country braces for the worst after hearing this news and after the immunization of over 730,000 children.
Sanofi urges physicians and health authorities to update the information regarding the vaccine.