In a letter written in late September to Charlotte Bronson, associate vice president for research, Dr. Dong-Pyou Han said he was “very ashamed” after admitting to falsifying AIDS vaccine research and would resign from his position.

Han was a member of Dr. Michael Cho’s research team which had obtained millions of dollars in federal grants to research possible AIDS vaccines.

“What we were trying to do is to develop immunogens that can infuse neutralizing antibodies against HIV-1,” said Cho.

Han said that the problem began as early as August 2009 when he realized rabbit blood samples that had been sent in for testing had been contaminated by human sera while Han had been working with both samples at the same time.

Though Han found that the data from the samples was wrong and had been compromised, he said he felt he could not tell Dr. Cho.

“At that time, I was afraid because the data was presented to our collaborators and others,” Han said.

In the letter, Han wrote that when he examined the uncontaminated samples, the neutralizing activity was either very weak or non-existent. Han said he “manipulated their activity … to look better.”

“In order to show the neutralizing activity continuously” in all samples, Han then spiked rabbit blood with human antibodies so it seemed as if the rabbit antibodies were defending against the HIV virus. Han then sent these samples to some other research organization so they would be able to duplicate the results.

In November, Han signed a voluntary exclusionary agreement with the United States Department of Health and Human Services as well as with Iowa State and other facilities involved in the research. Han agreed to exclude himself from contracting with and advising for any sort of government agency.

“I have regretted deeply the fact that I did and did not tell it,” Han said about his misconduct. “I was foolish, coward, and not frank.”

As for whether or not research will continue, “Certainly, we will be more cautious in interpreting results,” Cho said.