The country's case count rose to 28,602,101 with 513,137 deaths as of 19:32 Eastern Standard Time (EST) on Sunday, according to the CSSE tally.
US media said a nationwide telephone hotline and vaccine-appointment system for seasonal flu had been created in 2013 by the US Centers for Disease Control and Prevention (CDC).
The system was originally designed to provide free information for people who are sick and reduce the stress of medical institutions.
One year on since the COVID-19 hit the country, the system hasn't been applied to cope with the surging pandemic.
Andrew Needleman, chief executive officer of a software company involved in the system, said that adopting this system could possibly ease the rollout of COVID-19 vaccines, even if it would only be applied in a small scale.
Since its establishment in 2013, the system has gone through tests for five years. In 2018, a vaccine booking service was added. In the summer of 2020, the entire system was tested again. However, it has remained out of operation during the pandemic.