Dengue vax OK'd by FDA
Washington, D.C. — Dengvaxia, the live attenuated vaccine for preventing dengue disease, was approved by the FDA late Wednesday night for children ages 9-16 with laboratory-confirmed previous dengue infection and who live in dengue-endemic areas. The vaccine protects against symptomatic disease upon re-infection.
Dengue is endemic in the U.S. territories of American Samoa, Guam, Puerto Rico and the U.S. Virgin Islands, the agency said in a statement. It's transmitted by mosquitoes and re-infection in endemic areas is common.
If Dengvaxia (made by Sanofi Pasteur) sounds familiar, that's because it has been embroiled in controversy. The Philippines stopped using the vaccine and launched an investigation into its effects in December 2017, due to concerns about safety of the vaccine in young children. This prompted the World Health Organization (WHO) to recommend that the vaccine only be administered to individuals with laboratory-confirmed evidence of previous dengue infection.
A June 2018 New England Journal of Medicine analysis seemed to confirm those concerns, finding a higher risk of hospitalization among seronegative children who had received the vaccine compared to controls. The same analysis also found rates of hospitalization were much lower among seropositive children.
The FDA focused on the fact that Dengvaxia protects against all dengue virus serotypes (1, 2, 3, and 4), noting that vaccination will help protect previously infected people from the subsequent development of severe dengue disease.
"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," said Peter Marks, MD, director of the FDA's Center for Biologics Evaluation and Research.
Dengvaxia is not approved for individuals who have never been infected by any dengue virus serotype or "for whom this information is unknown," and the agency said healthcare professionals should evaluate individuals for prior dengue infection through medical records or serological testing prior to vaccination.