How many Black patients were immunized with DTaP in 2013?
Black patients refer to patient where race = 'black'; immunized with DTaP refers to DESCRIPTION = 'DTaP' from immunizations; in 2013 refers to DATE like '2013%';
SELECT COUNT(DISTINCT T1.patient) FROM patients AS T1 INNER JOIN immunizations AS T2 ON T1.patient = T2.PATIENT WHERE T1.race = 'black' AND T2.DESCRIPTION = 'DTaP' AND strftime('%Y', T2.DATE) = '2013'