"To build on our coordination with the relevant U.S. agencies, Pfizer launched this pilot program to help better support the states’ planning, deployment, and administration of the COVID-19 vaccine candidate. Learnings from this program will be adapted for usage across other states to help them create effective immunization programs for this vaccine," the company said in a press release.

According to Pfizer, the four US states were selected due to their differences in overall size, diversity of populations, and immunization infrastructure, as well as the need to reach populations both in rural and urban areas.

In a disclaimer of future preferential benefits for these four states, the company has stressed that they "will not receive vaccine doses earlier than other states by virtue of this pilot, nor will they receive any differential consideration."

Pfizer developed the vaccine in collaboration with German biotechnology company BioNTech. As the unregistered vaccine is underway with phase 3 clinical trials, the creators have declared above 90-percent efficiency.