The world crossed a coronavirus vaccine milestone this week: over 1 billion doses have now been produced.

The big picture: Production continues to ramp up quickly. While it took several months to reach one billion doses, we should hit two billion by the end of May, according to data from Airfinity, a science information and analytics company.

• China is the biggest producer and easily the biggest exporter, particularly now that India is curbing exports to fight a brutal second wave.
• Russia, Switzerland, South Korea, Brazil and South Africa are all producing doses but lag behind the five producers on our chart.
• The U.S. has kept nearly all of its supply for domestic use, but expects to become a major exporter once domestic needs are met. The White House has offered few details on that front, though, beyond saying a framework for dose-sharing is in the works.

The U.S. has also administered the most doses to date with 23% of the global total, according to Our World in Data.

• By the numbers: 21% of all vaccinations have come in China, 14% in India, 5% in the U.K. and 4% in Brazil. The continent of Africa has administered just 1.6% of the total.

Go deeper:

• India's second wave hits whole world through export curbs
• Biden's next challenge: Vaccine diplomacy
• The struggle to vaccinate Africa