Sixty-two percent of Americans say they have either received a COVID-19 vaccine or are seeking one as soon as possible, according to a poll released Tuesday by the Kaiser Family Foundation (KFF).

Since December, the poll has found more Americans are eager to get vaccinated. In December, just 34% said they were seeking a vaccine as soon as possible. In January, the number was up to 47%, and last month, 55% said they would get vaccinated as soon as possible.

The March 2021 poll found that 17% would wait and see, which is down significantly from past polls.

Roughly one-fifth of those polled said they would definitely not get a vaccine or only get one if required, which is consistent with recent polls.

The KFF poll also found that one-third of Americans who say they’re eligible for a vaccine have attempted to schedule a shot, but nearly half of them have been unsuccessful.

As of Tuesday, 28.9% of the US population is partially or fully vaccinated, and 16.1% are fully vaccinated, according to a CDC database.

How many Americans needing to be vaccinated to achieve herd immunity is a question scientists are still trying to grapple with. The threshold for herd immunity varies based on the transmissibility of a disease. For instance, measles requires 95% vaccination rates to achieve herd immunity, according to the World Health Organization, however for a disease like polio, only 80% need to be vaccinated for herd immunity.