Researchers at the Kaiser Family Foundation (KFF) found that 90,000 virus-related deaths since June 2021 - while the vaccine was widely available - were avoidable.
More than half, nearly 50,000, of these preventable deaths occurred in September, and 24,600 deaths occurring in August.
Researchers want health officials to do more to help reach the remaining 70 million unvaccinated Americans, and convince them to get the shots to protect themselves.
A KFF analysis finds that more than 90,000 deaths in the U.S. between June and September of 2021 - 80% of total deaths - could have been prevented by the COVID-19 vaccines
The researchers, who published their findings Wednesday as part of the Peterson-KFF Health System Tracker, used official death data from the Centers for Disease Control and Prevention (CDC) for their analysis.
Dr Krutika Amin, associate director of the tracker and one of the study's authors, told DailyMail.com that her team looked at the total number of reported Covid deaths in the four months from June to September 2021.
They excluded deaths that resulted from so-called 'breakthrough' infections, which occur when fully vaccinated people contract the virus.
Next, the team took the remaining deaths, and applied the reported 91 percent effectiveness of the vaccines at preventing death from the virus.
In total, they found 91,100 deaths in the U.S. that could have been prevented if those people were fully vaccinated.
Over that four-month time period, 102,469 Americans died from the virus, meaning that 89 percent of U.S. deaths over the period were preventable according to the KFF analysis.
Another analysis by KFF finds that unvaccinated Americans also cost $5.7 billion in avoidable hospital bills from June to August.
Amin believes health officials should try to relay these numbers