Sweden's approach is clearly one focused on long-term results. If Covid sees a resurgence in the fall or as nations return to relative normalcy, we can expect the infection and death counts to be multi-modal in most nations, while Sweden's might be a bell curve.
For this reason alone, we are unlikely to know the effectiveness of Sweden's herd immunity for months if not years.
For this reason alone, we are unlikely to know the effectiveness of Sweden's herd immunity for months if not years.