PolitiFact's ruling: False Here's why: Throughout the COVID-19 pandemic, the term "herd immunity" has been tossed around as a future benchmark of progress in the fight against the virus. For over a year, health officials and news organizations have analyzed what herd immunity means for COVID-19, and whether and when the United States might achieve it. But we recently came across a post on Instagram that makes a series of problematic claims about the effectiveness of vaccines and the concept of herd immunity. Notably, it asserts that the benchmark revolves only around vaccines and can’t realistically be achieved because, "100 percent of the population would have to be vaccinated for that to work."