The U.S. Food and Drug Administration (FDA) announced on May 1, 2019 its licensing approval of Sanofi Pasteur’s Dengvaxia vaccine, which was designed to prevent a mosquito borne viral infection known as dengue fever.1 Symptoms of dengue 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.2 According to an FDA news release, dengue fever is endemic in the U.S. territories of American Samoa, Guam, Puerto Rico and the U.S. Virgin Islands.1
The FDA confined the license for the live virus vaccine only to children aged nine to 16 years who have had a prior laboratory-confirmed prior dengue fever infection and who live in areas where the disease occurs regularly throughout the year. According to the FDA, Dengvaxia is not approved for use in individuals without lab confirmation of previous infection by any dengue virus serotype or for whom this information is unknown. This is because in people who have not been previously infected with dengue virus, the live virus Dengvaxia vaccine appears to act like a first dengue infection and increases the odds for severe complications if the vaccine fails to protect against a subsequent infection with wild type dengue virus.1
According to Peter Marks, MD, director of the FDA’s Center for Biologics Evaluation and Research:
Infection by one type of dengue virus usually provides immunity against that specific serotype, but a subsequent infection by any of the other three serotypes of the virus increases the risk of developing severe dengue disease, which may lead to hospitalization or even death.” He adds that, “As the second infection with dengue is often much more severe than the first, the FDA’s approval of this vaccine will help protect people previously infected with dengue virus from subsequent development of dengue disease.1
Earlier this year, Sanofi asked the FDA to approve Dengvaxia for people between the ages nine and 45 but the FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) decided that the vaccine was not effective in preventing the disease in adult patients living in endemic regions who have been previously diagnosed with dengue. The VRBPAC vote was 7-6 and one abstention.3
However, in patients between nine and 16 years old living in endemic areas with a previous diagnosis, the panel voted 13-1 supporting the vaccine’s efficacy in preventing forms of the disease caused by serotypes 1-4.3 According to Pharmafile, when considering the vaccine’s safety, the panel voted 7-7 against its use in adults but voted 10-4 in favor of its use for younger patients.3
The vaccine has had a controversial history since its launch in the Philippines in 2015. Dengvaxia was administered to over 700,000 Filipino students in a school-based government vaccination program in April 2016. In late 2017, Sanofi Pasteur announced that its dengue vaccine, Dengvaxia, could possibly lead to more severe cases of dengue fever in some people who get infected with the virus after being vaccinated. Studies revealed that giving the vaccine to people who had never contracted the disease leaves them vulnerable to severe complications if they subsequently contract the disease.4
This announcement came after 700,000 children were already given the vaccine in the Philippines. According to Sanofi, those who had never been previously infected with the dengue virus were at greatest risk. The government of Philippines suspended the use of the vaccine amidst concerns about its safety.4
On Mar. 1, 2019, the Department of Justice in the Philippines announced that it had found probable cause to charge six officials from French vaccine manufacturer Sanofi Pasteur, 10 Philippine health officials and officials of the country’s Food and Drug Administration and its Research Institute for Tropical Medicine with reckless impudence leading to the death of students. Ten students, who had never had dengue fever, were given Sanofi’s Dengvaxia vaccine and subsequently became infected with the dengue virus and did not survive.4
1 U.S Food and Drug Administration. First FDA-approved vaccine for the prevention of dengue disease in endemic regions. FDA.gov May. 1, 2019.
2 Mercola. J. Dengvaxia Vaccine May Lead to More Cases of Dengue. The Vaccine Reaction Jan. 2, 2018.
3 FDA advisory panel recommends Sanofi’s dengue vaccine in children, but rejects its use in adults. Pharmalife Mar. 11, 2019.
4 TVR Staff. Philippines to Charge Sanofi, Public Health Officials for Dengue Vaccine Deaths. The Vaccine Reaction Apr. 4, 2019.