Explain how an immune response start after macrophage attack a pathogen

After the macrophage fails the Helper T Cell stimulates the B cells (create antibodies) if pathogen is extracellular and Cytotoxic T Cells (killer T cells, release perforin) if pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
Hope that's helpful.

Problem-solving group. What they are describing is a group of kids trying to find the solution to the drop-out rate, which is a problem.