On January 8, 2023, China redefined COVID-19 as a Class B, rather than a Class A, infectious disease, marking the opening of a new phase in its COVID response. The transition was made possible by the country's scientists who developed a range of vaccines, the manufacturers who produced billions of doses of them, and the medical workers who administered them. Thanks to their concerted efforts, over 92 percent of the population has been vaccinated in a two-year-long mass campaign. In addition to meeting its domestic demand, China has also provided 2.2 billion doses of COVID-19 vaccines to more than 120 countries and international organizations. "Fighting COVID with Vaccines" investigates the key role vaccines have played in China's long battle against COVID-19.