Pfizer may win the COVID vaccine race. But distributing it could be another matter.

Pfizer, the multinational pharmaceutical company, may be the first in the United States to seek regulatory approval for a COVID-19 vaccine, but even if its vaccine is authorized, the company may face additional challenges in distributing it. That's because Pfizer's vaccine can't be stored in the refrigeration systems found at the typical doctor's office. Instead, it requires special ultra-low-temperature freezers that can store medicine at approximately 94 degrees below zero. The delivery system is complex, requiring the use of a custom-built 'cool box' that can store 1,000 to 5,000 vaccines for up to 10 days at minus 94 degrees.