In an effort to boost vaccination numbers on campus, Purdue University is giving away the equivalent of one year of education.

The digital apps act as ‘vaccine passports,’ essentially validating vaccinated users. And the demand is booming for one app in particular called iOpen.

Students ages 12-17 who get vaccinated are eligible in some states to win a huge prize: a fully-paid college education.

In just the last two weeks, more than 120 of nearly 400 public and private colleges and universities analyzed by NBC News have added vaccination requirements.