COVID-19 Public Health September 30, 2020While the US is most likely to reach COVID-19 herd immunity in the third or fourth quarter of 2021, it could come as early as the second quarter of 2021, if vaccines are highly effective and launched smoothly, or if significant cross-immunity is discovered in a population. But if early vaccine candidates have efficacy or safety issues, the pandemic could extend until 2022 or later. 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 “When will the COVID-19 pandemic end?,” September 21, 2020.