Polio vaccine incidents reduced public confidence in polio vaccine leading to a drop in vaccination rates. At the same time that Salk was testing his vaccine, both Albert Sabin and Hilary Koprowski continued working on developing a vaccine using live virus. During a meeting in Stockholm to discuss polio vaccines in November 1955, Sabin presented results obtained on a group of 80 volunteers, while Koprowski read a paper detailing the findings of a trial enrolling 150 people. Sabin and Koprowski both eventually succeeded in developing vaccines. Because of the commitment to the Salk vaccine in America, Sabin and Koprowski both did their
His Name Is Legs (Ladies and Gentlemen) for "His Name Is Legs" included tack piano, played by Canadian musician David Foster, and a new horn arrangement, played by Scott and Chuck Findley, another member of Harrison's tour band the previous year. Scott and Findley recorded their contributions at A&M Studios over 2–3 June, with each musician overdubbing two horn parts.<ref name="Extra Texture/YouTube">George Harrison interview, "Rockweek", (retrieved 13 September 2013).</ref> The released recording begins with an introductory bass riff from Weeks, which is then joined by Foster's tack piano. Commentators note the lack of clarity in the mix, which author Elliot Huntley attributes to the "three-pronged piano attack"