HIV particles, in green, can be seen budding from the surface of a lymphocyte.IMAGE: CDC/ C, GOLDSMITH P. FEORINO, E. L. PALMER, W. R. MCMANUSA new vaccine for simian immunodeficiency virus (SIV), a model for HIV, controlled SIV in half of tested rhesus monkeys, research published today (May 11) in Nature reports. The vaccine, which employs a viral vector that remains latent throughout the body for a lifetime, appears to keep T-cells active and ready to fight the invading virus.
"This is an absolutely momentous development," said pathologist Peter Barry of University of California Davis who was not involved in the research. "There is still room for optimization, but it's really quite remarkable that they're getting essentially 50 percent control."
Scientists have struggled to develop an effective vaccine against SIV and HIV, in part due to how quickly the viruses spread through the body and evolve to evade immune defenses. Previous vaccines, such as the one tested in the failed STEP trial in 2007, encoded HIV antigens into an adenovirus, but because the vector is short-lived, the memory T-cells generated by the vaccine retreat to the lymph nodes to await another attack. In this position, the T-cells are too slow to respond to an incoming ...
