Data from around the world continues to demonstrate the astonishing efficacy of the coronavirus vaccines approved for use in the United States. Where vaccinations are up, cases are low; where vaccinations are low, cases are up. And even in the incredibly rare “breakthrough” cases we have seen in the vaccinated, illness is mild and hospitalizations and deaths are close to zero. Given all this, we need to ask — why is there still vaccine hesitancy, and what approaches can we take to assuage it and move towards pushing vaccination rates? Will mandates be necessary, either from government or from the private sector? With New York City set to institute a partial mandate in the middle of September, we spoke with Professor Tara Kirk Sell, assistant professor at the John Hopkins Bloomberg School of Public Health and senior scholar at the Johns Hopkins center for health security, to discuss all these questions.