County of Macomb issued the following announcement on Jan 26.
The Macomb County Health Department is currently taking appointments for individuals age 12 and up who are eligible for booster doses of the Pfizer, Moderna and Johnson & Johnson COVID-19 vaccine. For more information, visit https://www.macombgov.org/VaccineCentral.
To make an appointment for a booster dose, click here https://bit.ly/3CxhDyg. Individuals who need help making an appointment can call the Macomb County Helpline at 586-463-3750. Although not encouraged, walk-up appointments are also welcome.
Original source can be found here.