The Great Barrington Declaration was an open letter published in October 2020 in response to the COVID-19 pandemic and lockdowns. It claimed harmful COVID-19 lockdowns could be avoided via the fringe notion of "focused protection", by which those most at risk of dying from an infection could purportedly be kept safe while society otherwise took no steps to prevent infection. The envisaged result was herd immunity within three months, as SARS-CoV-2 swept through the population.

During the early stages of the COVID-19 pandemic, a number of non-pharmaceutical interventions, particularly lockdowns, were implemented in numerous countries and territories around the world. These restrictions were established with the intention to reduce the spread of SARS-CoV-2, the virus that causes COVID-19. By April 2020, about half of the world's population was under some form of lockdown, with more than 3.9 billion people in more than 90 countries or territories having been asked or ordered to stay at home by their governments. Although similar disease control measures have been used for hundreds of years, the scale of those implemented in the 2020s is thought to be unprecedented.