The difference of serum to vaccination is that any resistence/immunity gained from serum will only last until the antibodies are eliminated from your blood. A

The difference of serum to vaccination is that any resistence/immunity gained from serum will only last until the antibodies are eliminated from your blood. A vaccine triggers an active immune response. That includes the differentiation of aptly-called "memory" B cells. Those can lie dormant for decades and spring into action when needed.