Morgan et al. (“The Use of Nonhuman Primate Models in HIV Vaccine Development”, PLoS Medicine 5(8), August 2008) insist that nonhuman primates (NHPs) constitute “the most rigorous approach” to judge HIV vaccine efficacy, and that “the best surrogate measure of vaccine efficacy” is “protection against disease progression in NHP studies.” Further, they “strongly recommend… NHP studies in a central role” in HIV vaccine preclinical evaluation. Yet, none of these conclusions can be drawn from available scientific evidence, given the comprehensive and extensive failure of NHP use in this area over the last quarter of a century.
Many hundreds of promising AIDS-vaccine trials in monkeys and chimpanzees have taken place, with almost 100 different vaccines of many types progressing to human testing in around 200 clinical trials: yet none has been effective clinically. This is illustrated comprehensively in my new study about to be published in Alternatives to Laboratory Animals (ATLA) , which details the differing responses of humans and chimpanzees to many types of HIV vaccines tested to date, with the same being true for macaques.
Billions of dollars, decades of time and many thousands of nonhuman primates’ lives have delivered nothing. The insistence of NHP researchers that they be allowed to push on with their models regardless is unscientific, and defies logic. The reported workshops that discussed how to use NHPs “more effectively” should have had the integrity to reflect on the past performance of NHPs in this field of research, and act and recommend accordingly. How could such a failed approach be utilized “more effectively?” It cannot. What science can do is use better human-relevant technologies that already exist and will deliver—when given a proper chance. The polio vaccine is an obvious (and just one) example of the benefits of using human-relevant research and testing methods, whereby an effective human vaccine was developed after years of floundering in NHP-based approaches.
As a recent review on the subject in the BMJ stated, “When it comes to testing HIV vaccines, only humans will do” . Until AIDS researchers using NHPs develop an unbiased and ethical perspective and begin to rely on the available scientific evidence regarding their approach, an HIV vaccine that protects humans rather than monkeys or chimpanzees will tragically remain a long way off.
1. Bailey J (2008) An assessment of the role of chimpanzees in AIDS vaccine research. ATLA 36: 1-47.
2. Tonks A (2007) Quest for the AIDS vaccine. BMJ 334(7608): 1346-8.