COVID-19 vaccines are designed to induce immunity against SARS-CoV-2, significantly reducing the risk of severe illness, hospitalization, and death. Developed at an unprecedented pace, the first clinical trials began in March 2020, with phases run in parallel to speed up approval, leveraging prior research on SARS and MERS coronaviruses. These vaccines utilize both classical methods (inactivated virus, protein subunits) and novel platforms like mRNA and viral vectors, a breakthrough that earned Katalin Karikó and Drew Weissman the 2023 Nobel Prize in Physiology or Medicine. Major vaccines include the Pfizer–BioNTech and Moderna mRNA shots, and the Novavax protein subunit vaccine, all of which have been updated as "variant-adapted" boosters to counter new variants and waning immunity. While common side effects are mild (soreness, fatigue, headache) and resolve quickly, the vaccines are widely credited with preventing an estimated 14.4 to 19.8 million deaths and are considered safe for pregnant and breastfeeding individuals. By August 2024, over 13 billion doses had been administered globally, marking the first effective human coronavirus vaccines ever created.