The Health Department of Northwest Michigan say that all vaccination appointments available now for the second round of COVID-19 shots have been filled. If you call in for an appointment now, there is no direct option to sign up. If you press the number prompt for COVID-19, you will be told that the only shots currently available are for health care providers and first responders. If you press the number for the general appointment prompt, you will eventually speak to a a person who will offer to put you on a standby list.
It is unclear at this point when more doses will become available.