Texas Education Code - EDUC § 22.051. Definition;  Other Immunity

(1) a superintendent, principal, teacher, including a substitute teacher, supervisor, social worker, school counselor, nurse, and teacher's aide employed by a school district;

(2) a teacher employed by a company that contracts with a school district to provide the teacher's services to the district;

(3) a student in an education preparation program participating in a field experience or internship;

(4) a school bus driver certified in accordance with standards and qualifications adopted by the Department of Public Safety of the State of Texas;

(5) a member of the board of trustees of an independent school district;  and

(6) any other person employed by a school district whose employment requires certification and the exercise of discretion.