How to confirm your second dose appointment at the Brazos County Community Vaccination Hub Hannah King and last updated 2021-05-14 10:48:58-04 BRAZOS VALLEY, TX â Heads up Brazos Valley! keep an eye out for their second dose appointment email. Since May 4, the location has only been issuing second doses of the COVID-19 vaccine. People needing to request a change in time can do so by reaching out to their call center at 979-703-1545. Additionally, individuals who received their first dose through the Hub and are approaching their forty-two days, but have not yet received an email for their second dose appointment, should call that number as well.