Only 47.1% of adults in Mississippi have received at least one dose of the vaccine—well below the national vaccination rate of 67.2%—and only 33.19% are fully vaccinated as of July 7.

So far, Mississippi governor Tate Reeves has said he is unconcerned. Last month, he told CNN that President Biden’s plan to vaccinate 70% of the U.S. population with one dose by July 4 was “arbitrary, to say the least.”

Reeves said the state is instead focusing on keeping case and hospitalization numbers under control. Earlier this week, Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases and President Biden’s chief medical adviser, said people in the state should consider wearing a mask despite being vaccinated due to the state’s large number of unvaccinated residents.

Although the likelihood of fully vaccinated people getting severely ill from the Delta variant is low, it can affect non-vaccinated people. Dr. Fauci said the variant is the greatest obstacle in the way of the U.S. eliminating COVID-19.

States in the South and Midwest have been slower to vaccinate citizens than others. Mississippi’s bordering states, Alabama (50.5%), Arkansas (53.2%), and Tennessee (52.9%) have among the lowest rates of residents who have gotten at least one shot.