The nation's food supply depends on more than 2 million farmworkers. Yet they are among the hardest of essential workers to get vaccinated for a variety of challenges, including the remoteness of farms from vaccine sites, long work hours, transportation, immigration status, language barriers, and lack of health insurance. The University of Arizona Health Sciences' mobile vaccine unit covers all of Maricopa County and tries to reach all underserved populations. At 9,200 square miles, Maricopa County is one of the largest counties in the U.S. and is as big as New Hampshire.