Jury Duty Summons for High Risk People

My husband has Type-1 Diabetes and received a jury duty summons. He's tired to request a postponement, but the doctors note he received (not from his doctor because she is on leave) was not very supportive. Does anyone know of a way he can postpone his jury duty without unnecessarily exposing himself to the virus? Even CDC guidelines state that immunocompromised people should "avoid large gatherings or places where people congregate." I'm sure the courthouse will practice social distancing, but being in an enclosed room with as many people as it takes to select a jury and run a trial massively increases his risk of exposure. He's been isolating for months and it would be crazy if he got sick from jury duty.