HOUSTON, Texas (KTRK) -- With the first COVID-19 vaccine drive-thru opening in Houston on Thursday, ABC13 wanted to know how the distribution plans are working out in other area counties not designated as hubs by the state. All 13,000 appointments for a vaccine were full at NRG park as Memorial Hermann began administering the first dose in their drive-thru clinic. It will continue through Sunday. But note, that you must have an appointment. You cannot just show up because you will not receive a shot. This clinic is the latest to open up in the Houston area as health officials try to coordinate mass vaccination with a very limited supply, which has been frustrating for people who have been trying to get an appointment.