Global coronavirus cases surpassed 100 million on Wednesday, according to a Reuters tally. That's a staggering 1.3 percent of the world's population. Countries across the globe are struggling with new variants of the virus and vaccine shortfalls, while more than 2 million people have died from the disease. The United States, India, Brazil, Russia and the United Kingdom round out the top five worst-affected countries. Together, their populations represent over a quarter of the globe, but their case numbers make up more than half of of those reported. With over 25 million cases alone, the United States has a quarter of all reported COVID-19 cases, though it accounts for just 4 percent of the world's population. It also leads the world in the number of lives lost to the disease with over 420,000 deaths, followed by Brazil. In India, the nation with the second-highest number of cases, infections have been decreasing, but still hover around 13,000 a day on average. And as the worst-affected region in the world, Europe is currently reporting a million new infections about every four days, and has reported nearly 30 million since the global health crisis began. For leaders everywhere, vaccines are the light at the end of the tunnel. Although roll-outs have started in about 56 countries, vaccine distribution across the world remains unequal. Africa, which accounts for nearly 3.5 million cases and over 85,000 deaths, is still scrambling to secure vaccine supplies, and many European countries are facing shipment delays from major vaccine makers like AstraZeneca and Pfizer. Meanwhile, a new threat has emerged: COVID-19 variants, one first identified in Britain, and another in South Africa, which is 50 percent more infectious, and now spreading in at least 20 countries.