The global coronavirus pandemic has sparked an economic "crisis like no other," sending world GDP plunging 4.9 percent this year and wiping out $12 trillion over two years, the IMF said Wednesday.

Worldwide business shutdowns destroyed hundreds of millions of jobs, and major economies in Europe face double-digit collapses.

The prospects for recovery post-pandemic -- like the forecasts themselves -- are steeped in "pervasive uncertainty" given the unpredictable path of the virus, the IMF said in its updated World Economic Outlook.

"The COVID-19 pandemic has had a more negative impact on activity in the first half of 2020 than anticipated, and the recovery is projected to be more gradual than previously forecast," the fund warned.

While businesses are reopening in many countries and China has seen a bigger rebound in activity than expected, a second wave of viral infections threatens the outlook, the report said.

World GDP is expected to rebound by just 5.4 percent in 2021, and only if all goes well, the IMF warned.