New Vaccine That Protects Monkeys against Avian Flu is Ready for Human Trials
ScienceDaily (Nov. 9, 2007) — Researchers from the National Institutes of Health and University of Maryland report that a new vaccine that protects monkeys against the avian influenza virus is now a candidate for clinical trial in humans.
In the study researchers developed a live vaccine incorporating the avian Newcastle disease virus (NDV), which expresses a common gene found in the H5N1 avian influenza virus, and tested it in African monkeys. The vaccine was administered both intranasally and through the respiratory tract in two doses with a 28-day interval in between.
Response after one dose showed low amounts of virus shedding indicating protection. Following two doses, high levels of neutralizing antibodies were present in all immunized monkeys. A substantial response to either dosage was noted in the respiratory tract indicating a likely reduction in transmission in the event of an outbreak.
"In this study, we have developed a vaccine candidate, NDV-HA, for immunization against H5N1 HPAIV and have tested it in a nonhuman primate model," say the researchers. "The vaccine was well tolerated and induced substantial local and systemic immune responses, demonstrating that NDV has potential as a live virus candidate vaccine against HPAIV."