The Secretary may establish 20 officer positions in the Epidemic Intelligence Service Program, in addition to the number of the officer positions offered under such Program in 2006, for individuals who agree to participate, for a period of not less than 2 years, in the Career Epidemiology Field Officer program in a State, local, or tribal health department that serves a health professional shortage area (as defined under section
254e
(a) of this title), a medically underserved population (as defined under section
254b
(b)(3) of this title), or a medically underserved area or area at high risk of a public health emergency as designated by the Secretary.