Martin Kulldorff is a Swedish biostatistician. He was a professor of medicine at Harvard Medical School from 2003 until his dismissal in 2024. He is a member of the US Food and Drug Administration's Drug Safety and Risk Management Advisory Committee and a former member of the Vaccine Safety Subgroup of the Advisory Committee on Immunization Practices at the Centers for Disease Control and Prevention.

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.