A representative for Paramount Global declined to comment.
The ad, which adapted footage from a famous 1960 Kennedy campaign ad, drew criticism from some members of the Kennedy family, many of whom have criticized him for spreading conspiracy theories about vaccines and promoting other misinformation.
In a post on the social media site X on Sunday night, Mr. Kennedy distanced himself from the spot, noting that the super PAC is legally barred from consulting with the campaign, and saying he was “so sorry if the Super Bowl advertisement caused anyone in my family pain.”
As of Monday afternoon, the ad was still pinned to his profile, although it was later taken down. Stefanie Spear, the press secretary for the Kennedy campaign, did not respond to a request for comment on Monday. On Sunday, she said the campaign had been “pleasantly surprised and grateful” for the ad.
Ms. Shanahan, 38, is a lawyer and tech entrepreneur in the Bay Area who has invested in scientific research, particularly in the areas of health and the environment. She was married to Mr. Brin in 2018; their divorce was finalized last summer.
Ms. Shanahan, who has a record of giving to Democrats — including to President Biden’s campaign in 2020 — and described herself on Monday as a “progressive through and through,” gave the maximum $6,600 contribution to Mr. Kennedy’s presidential campaign in May, when he was still seeking the Democratic nomination, records show.