US Army researchers accused of giving positive spin to a vaccine trial that was predicted to fail because the strategy is wrong Dr. Mae-Wan Ho
A large clinical trial of an AIDS vaccine carried out by the US Army and its collaborators in Thailand showed that the vaccine offered protection against HIV infections by about a third. The announcement, made at press conferences on 24 September 2009, raised hopes that a positive AIDS vaccine will finally become available.
But since then, two published accounts have dashed these hopes. Researchers given confidential briefings on the trial data, revealed that the results were weaker than even the modest success claimed . In particular, when the results were analyzed according to protocol – when only those who got all six vaccine shots at the right time and were followed up to the end of the trial were included - no statistically significant protection was found.
The public announcement was based on the result obtained by including every participant in the trial. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases defended the announcement, and rejected the accusation of a cover-up.
As reported by Jon Cohen in Science magazine , of those who had received any doses of the two vaccines used in combination, 51 had infections, compared to the 74 that became infected in the placebo group. This difference represented an efficacy of 31.2 percent, statistically significant at 4 percent probability. When only the participants in both groups that had rigorously followed the protocol were included, the efficacy was reduced to 26 percent, and the difference between vaccine and placebo groups was not statistically significant.
Researchers were critical of the way the announcement was made to the press. One leading HIV/AIDS investigator, who, like others, wished to remain anonymous, told Cohen :”The press conference was not a scholarly, rigorously honest presentation. It doesn’t meet the standards that have been set for other trials, and it doesn’t fully present the borderline results. It is wrong.”
Two biostatisticians said that the results based on participants who had all the shots are the more important data, and were puzzled that the press conference did not include that analysis.
The trial involved RV114, a combination of a modified canary-pox vaccine from Sanofi Pasteur and an engineered version of a protein of the AIDS virus, made by a Brisbane biotechnology company VaxGen Inc. The phase 3 trial is a two-pronged or “prime-boost” approach: Sanofi’s vaccine “primed’ the body’s immune system to attach HIV, while the drug developed by VaxGen “boosted the response .
Half of the more than 16 000 participants were given the vaccines in 2006, and half received placebos. All were provided with condoms, counseling, regular HIV testing and treatment for any sexually transmitted diseases. Of the 8 197 participants given the vaccine, 51 became infected, while 74 became infected in the 8 198 given the placebo.
One puzzling aspect of the results was that people who received the vaccine and still got infected did not have lower levels of the virus than those who got infected in the placebo group. In other words, immune response against HIV did not prevent the virus from replicating.
The debate will have little practical consequences, however, because even on the most positive interpretation, the efficacy is too low to be a serious vaccine candidate . Experts generally agree that vaccines need to have 70 to 80 percent efficacy to be useful.
The Thai vaccine trial itself was controversial from the start, as we reported in  (Unraveling AIDS, Chapter 11, I-SIS publication). Dennis Burton at the Scripps Institute, La Jolla, California and 17 other scientists signed a letter published in the Policy Forum of the Science, expressing “concern about the wisdom” of the phase 3 trial, doubting the efficacy of the vaccine, and objecting to the approval process which “lacked input from independent immunologists and virologists, who could have judged whether the trial was scientifically meritorious.”
The reply from Robert Belshe at St. Louis University School of medicine and 12 others defended the trial, stating that: “Regardless of the specific vaccine efficacy, the trial will make a substantial contribution to HIV vaccine research.” In other words, as we pointed out at the time, the volunteers were being used as guinea pigs, and neither the efficacy, nor indeed safety is considered an issue.
ISIS has published a string of articles warning against vaccines containing the gp120 protein from HIV; see for example  AIDS-Vaccines Trials Dangerous (ISISNews 11/12) and  AIDS Vaccines Worse Than Useless? (SiS 19), which is strongly suspected of increasing autoimmune response in those vaccinated and may compromise their ability to protect against HIV infection.
Researchers have gained next to nothing from decades of failure in this main approach to AIDS vaccines. It is simply a mistake that ought to be been abandoned at least ten years ago in favour of other more promising developments to prevention and therapy .
Article first published 05/11/09
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