The swift development of effective vaccines against COVID-19 was an unprecedented scientific achievement. But production challenges, vaccine nationalism, and new variants have all presented hurdles.

A growing number of countries are legalizing same-sex marriage amid a steady advance in rights for LGBTQ+ people, but opposition remains strong in many others.

Responsible for powering the country and its economy, the U.S. energy grid has come under increasing strain due to climate change, and the threat of cyberattacks looms.