Carlton County Public Health and Human Services will hold a free Moderna booster clinic 9 a.m. to 2:30 p.m. Friday, Jan. 21 in the second-floor conference room at the Carlton County Community Services Building, 14 N. 11th St., Cloquet. Registration is required due to limited doses, so visit https://prepmod.health.state.mn.us/appointment/en/reg/8569570121 to make an appointment.