COVID-19 Public Health North America February 9, 2021To acquire COVID-19 herd immunity, the United States needs more than three times as many vaccine doses as for the annual flu shot and twice as many doses per month as the H1N1 flu vaccine drive in 2009, mainly due to double-dose requirements for some COVID-19 vaccines. We strive to provide individuals with disabilities equal access to our website. If you would like information about this content we will be happy to work with you. Please email us at: McKinsey_Website_Accessibility@mckinsey.com To read the article, see “The risks and challenges of the global COVID-19-vaccine rollout,” January 26, 2021.