The Wall Street Journal reported Pfizer cut the number of vaccines it planned to ship in 2020.
According to Business Insider, this is due to supply chain delays.
Sources say Pfizer sourced materials and set up supply chains while developing a vaccine.
This is an "unprecedented" move in the world of medicine and vaccine development.
But Pfizer and BioNtech maintain they will produce 1.3 billion doses by the end of 2021.
