From the Summary: "The Coronavirus Disease 2019 (COVID-19) pandemic has led to severe health and economic consequences across the globe, with country governments struggling to contain the spread of the disease through physical lockdown and quarantine measures, while working towards vaccines, to prevent further morbidity (illness) and mortality (death). As of December 8, 2020, COVID-19 cases had reached roughly 67 million, with over 1.5 million deaths globally. The successful deployment of a COVID-19 vaccine globally could curb spread of the virus by aiding in creating herd immunity; whereby a high proportion of individuals within a population are resistant to infection based on pre-existing immunity (through vaccination and/or previous infection). At least 200 experimental COVID-19 vaccine candidates are under development worldwide. As of November 30, 2020, several companies, including Pfizer and Moderna, had requested emergency use authorization from the Food and Drug Administration (FDA) for their vaccine candidates. Vaccine development is typically a long, complex, and difficult process that can take decades. However, given the urgency of controlling the COVID-19 pandemic, governments, philanthropies, international organizations, scientists, and manufacturers are expediting research and development (R&D) for COVID-19 vaccines and other medical countermeasures. The stated goal of many entities is making a vaccine widely available within two years."
CRS Report for Congress, R46633
Congressional Research Service: https://crsreports.congress.gov/