What is HBeAb?

Hello. I'm a student of international law, and I was hopping someone could give me some answers.
Recently, there was one action on my faculty performed by some enthusiast from medical faculty. It was about some vaccines against hepatitis.
They offered free vaccines and first they needed to take a blood sample from every one of us.
I didn’t know why do they need a blood sample and there so I asked one of them. He said to me that the reason of this is to determine does someone of us already is infected with this hepatitis, to be more correct, they searched for some HBeAb in our blood.
What the hell is HBeAb?

I’ll try to help you because I’m also medical student and I’ll try to explain this as simple as possible.
Hepatitis is caused by one virus called HBV virus. HBV is a DNA virus of the Hepadnaviridae family.
Hepatitis B vaccine is available to prevent an HBV infection.
DNA polymerase is one enzyme in human body which occurs only after infection with this virus. They are therefore a good marker of viral activity, but testing them is expensive and difficult, therefore they are not used as standard tests.
HBeAg is a peptide that is produced and becomes detectable in serum during HBV replication.
Only problem is that there is very small amount of these antigens in human blood.
Human body in contact with this antigen- HBeAg is producing antibodies-HBeAb but there are much more of these antibodies and there are very easy to detect.
So, presents of these HBeAg antibodies means you got hepatitis infection.