Dengue vaccine enters phase 3 trial

The Butantan Institute has launched a phase 3 trial for TV003, a dengue vaccine produced by researchers at the NIH’s National Institute of Allergy and Infectious Diseases, or NIAID, according to a press release.

“Researchers in NIAID’s Laboratory of Infectious Diseases spent many years developing and testing dengue vaccine candidates designed to elicit antibodies against all four dengue virus serotypes,” Anthony S. Fauci, MD, director of NIAID, said in the release. “Earlier clinical trials of this candidate conducted in the United States by NIAID showed that it could elicit a robust antibody and cellular immune response after just one dose.”

Anthony S. Fauci

According to the release, the Butantan Institute, a nonprofit producer of immunobiologic products for Brazil, is sponsoring the double blind, placebo-controlled, multicenter trial. It will enroll about 17,000 healthy participants aged 2 to 59 years from 13 Brazilian cities. Two-thirds of participants will receive a single dose, while the remainder will receive a placebo. The researchers will monitor participants during visits to a health clinic and through telephone and text communications for 5 years.

Dengue is common in tropical areas, placing half of the world’s population at risk for infection, according to the release. WHO estimates that 400 million infections and 500,000 hospitalizations occur annually. Brazil reported more than 1.5 million cases in 2015.

“Because the impact of dengue fever in Brazil is especially large and the country has an excellent health infrastructure,” Fauci said, “it is an ideal location to test the vaccine candidate.”

Four virus serotypes cause dengue, the release said. Transmission occurs through Aedes aegypti mosquitoes. A person exposed to one serotype develops immunity to that virus, but not to the others. Instead, exposure to one serotype, increases the severity of subsequent infections caused by other serotypes.