A COVID‑19 vaccine is a vaccine intended to provide acquired immunity against severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), the virus that causes coronavirus disease 2019 (COVID‑19). Prior to the COVID‑19 pandemic, an established body of knowledge existed about the structure and function of coronaviruses causing diseases like severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). This knowledge accelerated the development of various vaccine platforms during early 2020. The initial focus of SARS-CoV-2 vaccines was on preventing symptomatic, often severe illness. On 10 January 2020, the SARS-CoV-2 genetic sequence data was shared through GISAID, and by 19 March, the global pharmaceutical industry announced a major commitment to address COVID-19. The COVID‑19 vaccines are widely credited for their role in reducing the spread, severity, and death caused by COVID-19.

As of 10 September 2021, 5.66 billion doses of COVID‑19 vaccine have been administered worldwide based on official reports from national public health agencies. AstraZeneca anticipates producing 3 billion doses in 2021, Pfizer–BioNTech 1.3 billion doses, and Sputnik V, Sinopharm, Sinovac, and Janssen 1 billion doses each. Moderna targets producing 600 million doses and Convidecia 500 million doses in 2021. By December 2020, more than 10 billion vaccine doses had been preordered by countries, with about half of the doses purchased by high-income countries comprising 14% of the world's population.

COVID-19 vaccine clinical research is the clinical research on COVID-19 vaccines, including their efficacy, effectiveness and safety. There are 22 vaccines authorized for use by national governments, with six vaccines being approved for emergency or full use by at least one WHO-recognised stringent regulatory authority; and five of them are in Phase IV. 204 vaccines under clinical trials that have not yet been authorized. There are also nine clinical trials on heterologous vaccination courses.

In Phase III trials, several COVID‑19 vaccines have demonstrated efficacy as high as 95% in preventing symptomatic COVID‑19 infections.