Anti-vaccine activist Robert F. Kennedy, Jr., apologized Tuesday for suggesting things are worse for people today than they were for Anne Frank, the teenager who died in a Nazi concentration camp after hiding with her family in a secret annex in an Amsterdam house for two years.

Kennedy’s comments, made at a Washington rally on Sunday put on by his anti-vaccine nonprofit group, were widely condemned as offensive, outrageous and historically ignorant. It’s the second time since 2015 that Kennedy has apologized for referencing the Holocaust during his work sowing doubt and distrust about vaccines.

“I apologize for my reference to Anne Frank, especially to families that suffered the Holocaust horrors,” Kennedy said in a tweet Tuesday morning. “My intention was to use examples of past barbarism to show the perils from new technologies of control. To the extent my remarks caused hurt, I am truly and deeply sorry.”

Kennedy’s wife, the actress Cheryl Hines of HBO’s Curb Your Enthusiasm, distanced herself from her husband in her own tweet about 20 minutes later. She called the reference to Anne Frank “reprehensible and insensitive.”

“The atrocities that millions endured during the Holocaust should never be compared to anyone or anything. His opinions are not a reflection of my own,” Hines tweeted.

Kennedy, a nephew of President John F. Kennedy and the son of his slain brother, former U.S. attorney general, civil rights activist and Democratic presidential contender Robert F. Kennedy, on Sunday had complained that the nation’s leading infectious disease doctor, Anthony Fauci, was orchestrating “fascism.”

“Even in Hitler’s Germany, you could cross the Alps to Switzerland. You could hide in an attic like Anne Frank did,” he told the crowd.

An investigation by The Associated Press last month found that Kennedy has invoked the specter of Nazis and the Holocaust when talking about public health measures meant to save lives during the pandemic, such as requiring masks or vaccine mandates.

Last month, for example, he put out a video that showed Fauci in a Hitler mustache. In an October speech to the Ron Paul Institute, he obliquely compared public health measures put in place by governments around the world to Nazi propaganda meant to scare people into abandoning critical thinking.

Kennedy apologized in 2015 after he used the word “holocaust” to describe children whom he believes were hurt by vaccines.

In his Tuesday apology, Kennedy did not address his past invocations of Nazis, Hitler and the Holocaust when discussing vaccines. Representatives of his nonprofit, Children’s Health Defense, did not return emails asking about his past comments.