The actor made the comments during a special episode of his wife Jada Pinkett Smith’s talk show, Red Table Talk, which aired on Wednesday.
In the 2007 I Am Legend, a virus wipes out most of humanity, turning people into bloodthirsty mutants. Smith’s character, a virologist named Robert Neville, as one of the rare humans left.
“I wanted to do this because in  I made I am Legend, so I feel responsible for a lot of the misinformation,” he said.
Smith added that while preparing for his role as a virologist, he had a chance to visit the CDC.
“It really changed my life and how I looked at the world,” he said of his preparation.
The rest of the show featured Dr Michael Osterholm, the director of the Centre for Infectious Disease Research and Policy at the University of Minnesota, who provided his expertise.
Italy's death toll from the coronavirus has overtaken China's, underscoring just how much the outbreak has pivoted towards Europe as well as the US. The Middle East and Africa also are seeing a worrying number of new cases.
The grim news from Italy followed the announcement from Chinese authorities that there were no new cases to report from the former epicentre of the virus, which had once seen thousands of cases a day, and its surrounding province.
Additional reporting by agencies
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