SAN FRANCISCO, Calif. (KRON) — Pfizer Inc. says it will ship half of the COVID-19 vaccines it originally aimed for this year due to supply-chain problems, according to the Wall Street Journal.

However, Pfizer still expects to ship out more than a billion doses in 2021.

Pfizer and BioNTech SE had planned to ship out 100 million vaccines world-wide by the end of 2020. They will now ship around 50 million.

The U.S. Food and Drug Administration is reviewing the vaccine and hoping that authorization and distribution will come before the end of the year.

More than 14 million people have contracted the virus in the U.S. and more than 275,000 Americans have died, according to the latest data from Johns Hopkins.