"I wouldn't have imagined in my wildest dreams that people who object to things that are pure public health principles ... that to me is just strange," he said Wednesday at a public forum hosted by the Harvard School of Public Health.
He said his three daughters have also been the subjects of harassment.
"[The pandemic] brings out the best of people and the worst of people. And you know, getting death threats for me and my family and harassing my daughters to the point where I have to get security is just, I mean, it's amazing," he said.
The 79-year-old epidemiologist said in April that concerns about his safety were serious enough that he now has security through the U.S. Marshals Service.
As COVID-19 conspiracy theories seem to spread as quickly as the virus itself, Fauci has been vilified by some conspiracy peddlers on the far right as a part of the anti-Trump deep state.
For example, a professionally made 26-minute video, titled "Plandemic," alleges that Fauci manufactured the virus and shipped it to China was watched more than 8 million times before the platforms took action.