This year looks very different from the last when it comes to the pandemic, and that’s largely thanks to the COVID-19 vaccines—three of which, from Pfizer-BioNTech, Moderna and Johnson & Johnson–Janssen, are approved or authorized by the U.S. Food and Drug Administration. The vaccines use different technologies and have reduced rates of severe COVID-19 as well as hospitalizations and deaths. But with new variants, including Delta, that protection, while still strong, is waning. That’s why countries including the U.S. are authorizing booster shots to strengthen that immunity. —Alice Park
More Must-Reads From TIME
- Taylor Swift Is TIME's 2023 Person of the Year
- Meet the Nation Builders
- Why Cell Phone Reception Is Getting Worse
- Column: It's Time to Scrap the Abraham Accords
- Israeli Family Celebrates Release of Hostage Grandmother
- In a New Movie, Beyoncé Finds Freedom
- The Top 100 Photos of 2023
- Want Weekly Recs on What to Watch, Read, and More? Sign Up for Worth Your Time