The quantity and quality of the immune responses needed to control HIV are unknown. Esparza noted that the correlates of immunity remain unknown even in diseases for which effective vaccines are available. The debate over the scientific versus the empiric approach to AIDS vaccine development. It must prevent all disease. Immune responses elicited by a vaccine must be those seen in natural infection.
Vaccines always induce life-long immune responses.
Protective efficacy must be demonstrated in animal models before human efficacy trials can begin. Correlates of protective immunity must be known before efficacy trials can begin. Only one efficacy trial will be needed. Trials that fail to demonstrate efficacy will set back research. These misconceptions, Esparza said, must be replaced by an iterative process between basic science and clinical trials.