Note: The aborted fetal cell line PER C6 which was used in the Merck AIDS vaccine is modified by Crucell NV with the troubling AD 5 vector. PER C6 AD5 has been known to cause cancerous tumors in nude mice - and apparently, increased the risk of contracting HIV. And since PER C6 AD 5 is being used to develop numerous other new vaccines for diseases such as influenza, Avian flu, West Nile virus, Ebola, Marsburg Disease - how many patients in clinical trials are going to have the same reaction the HIV candidates did? If participants in the clinical trials had a preexisting immunity to the common cold virus (AD5) what will happen when they begin testing these other new vaccines that also employ PER C6/AD 5?
For more information on PER C6 AD5 CLICK HERE.
Failure of AIDS Shot Linked to Cold Virus
Thursday, November 8, 2007; Page A24
The announcement, made in Seattle, was the latest bad news for a vaccine that only two months ago was regarded as the most promising candidate to slow an epidemic that kills millions of people each year. Trials of the vaccine that involved thousands of participants in the United States, South Africa and other countries were halted in September.
"This is a clinically important finding that we have to address," said Keith Gottesdiener, a vice president for Merck Research Laboratories, which developed the vaccine in conjunction with the National Institutes of Health. He spoke from Seattle, where researchers made the announcement at a scientific conference.
The setback has forced a broad reexamination of the multibillion-dollar search for an AIDS vaccine and raised new questions about when -- or whether -- future experimental vaccines should be tested on humans.
Debate has sharpened in particular over the next major trial of a vaccine, developed by the National Institutes of Health and due to begin human testing in just a few months.
For the Merck vaccine, researchers genetically altered the adenovirus type 5, one of several viruses that cause colds, to include elements of HIV. The goal was to trigger an immune response that would protect a vaccinated person from contracting HIV.
But for reasons scientists do not understand, study subjects with preexisting immunity to adenovirus type 5 apparently became more vulnerable when vaccinated. Among the nearly 800 study subjects with high levels of this immunity, 21 of those who were vaccinated contracted HIV, compared with nine of those who received a placebo.
From a statistical perspective, the numbers were small, but the finding has alarmed vaccine scientists worldwide. The study was shut down Sept. 21 because the vaccine was found to be ineffective.
Researchers say the vaccine did not cause the cases of HIV but may have altered the immune systems of subjects in ways that made some subjects more vulnerable to infection. Analysis of the data is continuing.
"Until we answer some of these questions, we're in a bit of a holding pattern," Mitchell Warren, executive director of the AIDS Vaccine Advocacy Coalition, said in Seattle.
Scientists at the conference were also debating whether to tell each of the study participants, including about 3,000 people in the United States and Latin America, whether they received the placebo or the vaccine, a process called "unblinding" the study.
Gottesdiener said he expected the ethical oversight board to make a decision within the next 10 days.
Researchers in South Africa, who were testing the same vaccine, unblinded their study last month, saying that 801 study participants needed to know if they faced increased risk.
The search for an AIDS vaccine began in the mid-1980s and last year alone cost more than $900 million in private and government funding.