COVID-19 has killed 4 million people as of Thursday, while the Delta variant becomes the dominant strain around the world.
It's a grim milestone in a health crisis still ravaging countries like Brazil and India.
According to a Reuters analysis, it took over a year for the death toll to hit 2 million, while the next 2 million were recorded in just over 5 months.
While the number of cases and deaths have slowed in countries like the U.S. and UK, hospitals are overrun in much of Latin America.
The region is facing its worst outbreak since March, as countries like Bolivia, Chile, Brazil and Uruguay struggle to contain the disease and inoculate their populations.
Pan American Health Organization Director, Carissa Etienne, said earlier this week, "The primary issue in the Americas is vaccine access, not vaccine acceptance."
The wealthy Group of Seven (G7) nations pledged to provide 1 billion COVID-19 vaccines to countries that need supply like India, which is still reporting one of the highest average death tolls per day.
The country accounts for one in every three deaths reported each day, according to a Reuters analysis.
Even still, health experts believe the official death toll worldwide is undercounted.