Open COVID-19 vaccine slots fill within minutes, more than 300,000 people sit on virtual waiting list New vaccine appointments in Houston has those already registered asking questions FOX 26 Reporter Matthew Seedorff has more as new vaccine appointments are being opened for the COVID-19 vaccine in Houston, but those who are already registered are still waiting. HOUSTON - This week, COVID-19 vaccine distribution is at an all-time high in Harris County. A FEMA mega-site opened Wednesday, planning to vaccinate roughly 6,000 people a day for the next several weeks. According to County and City leaders, those who registered online for wait-lists in Harris County or the City of Houston are being selected for the mega-site.