Graph of "Bear Case Herd Immunity".The x-axis represents time from Dec 2020 to Dec 2021, and the y-axis shows the percentage of the U.S population with immunity. The graph illustrates the scenario where immunity levels in the population may not be sufficient to achieve herd immunity against a specific disease or virus. The line shows a slow and gradual increase in immunity over time, but it may not reach the threshold required for effective herd immunity.