The most important findings from this study were that there were seven (4.5%) infants who were unresponsive to HB vaccination, the sex distribution (50.3% girls vs. 49.7% boys) was nearly equal, and the age of completing the primary HB vaccine series was less than 6 months (59.4%), in accordance with the national HB vaccination program, with vaccines administered at the ages of 0, 2, 3, and 4 months. This evidence concerns the gene GSTM1 and hemoglobin measurement.