The patent was not for Covid-19; it was connected to a potential vaccine for a different coronavirus that affects poultry. But two days later, the conspiracy website Infowars inaccurately said the patent was for “the deadly virus.”
The idea spread. From February to April, conspiracy theories involving Mr. Gates and the virus were mentioned 1.2 million times on social media and television broadcasts, according to Zignal Labs. That was 33 percent more often, it said, than the next-largest conspiracy theory: that 5G radio waves cause people to succumb to Covid-19.
Some of the theories tapped into Mr. Gates’s acquaintance with Jeffrey Epstein, the financier who was convicted of sex trafficking and committed suicide, saying a global elite had banded together to create the coronavirus.
In other theories, internet trolls twisted comments that Mr. Gates had made. In one, trolls said Mr. Gates, who had raised the idea of “digital certificates” to confirm who had the virus, wanted to surveil the population with microchip vaccination implants.
By April, false Gates conspiracy theories peaked at 18,000 mentions a day, Zignal Labs said.
The theories were amplified by people such as Mr. Kennedy, a son of former Senator Robert F. Kennedy, who campaigns against vaccines as a director of the Children’s Health Defense network. On his Instagram page, Mr. Kennedy has said Mr. Gates pushes vaccines to feed his other business interests.
On Tuesday, Mr. Kennedy posted a cartoon of a smiling Mr. Gates with a syringe and a caption: “Your Body, my choice.”
Mr. Kennedy, whose Instagram followers have doubled to more than 285,000 since March, said in an interview that he was telling the truth about the “terrible damage” that Mr. Gates had inflicted on the world with vaccines.