The U.S. is on pace to hit President Biden's goal of at least one dose of vaccine for 70% of U.S. adults by July 4.
One model says that could happen by the end of this month.
More than 108 million people are fully vaccinated, but there's concern about a drop in demand with people who are hesitant still holding out.
Some promising news though, incentives and requirements could encourage some holdouts to get their shot.
The Kaiser Family Foundation surveyed more than 2,000 adults last month and found 3 in 10 would be more likely to get the vaccine if it was offered at a place they normally go to for health care, if airlines required it to travel or if only one dose was needed.
25% said they'd be more likely to get it if their employer paid them an extra $200 to roll up their sleeve for the shot.