I'm a nursing student and as you know it is required to have the Hep B vaccine before starting the clinicals. I got the series in '93 but still needed a titer. My results were negative. I was told by the urgent care I went to that all I needed was a booster and to retest. I was also told by my PA friend to get one more dose and then retest (I'm not sure if there is a difference). I asked my school secretary whether I could get a booster and then retest, but she insisted I needed to redo the whole series and then retest. She said that it is what the hospitals require. I'm gonna do what she says b/c obviously she is the one that has to approve me to go, but I'm just curious, for educational purposes, why there would be a need to redo the whole series if getting a booster or another dose proved to be sufficient. Is the three dose safer or stronger than a booster?Thanks.