Former ISU researcher Dong-Pyou Han was sentenced to 57 months in prison Wednesday for his role in falsifying research results, The Des Moines Register reported.

Han will also have to repay $7.2 million to the National Institutes of Health, though how much of that money will be collected is unclear as Han qualified for a public defender. The NIH granted up to $20 million in federal funding for the research. 

Han was a research assistant of biomedical sciences at Iowa State. In 2013, he admitted to adding uninfected human blood to the HIV-infected rabbit blood in an effort to make it appear that an AIDS vaccine was a success. 

On Feb. 25, 2015, Han pleaded guilty to research fraud.  

After serving the nearly five-year sentence, Han will be on supervised release for three years.