Another benefit is cell memory. If you see the vaccines kids get, almost all are multiple shots. Including 3-4 shots for Hep-B. It's nothing new. The reason is

Another benefit is cell memory. If you see the vaccines kids get, almost all are multiple shots. Including 3-4 shots for Hep-B. It's nothing new. The reason is body takes repeat threat more seriously and builds the cell memory. So even when the antibody is gone the cell memory tells body to act quickly and what to do.