When the third wave began to subside in late April, only about 5% of the population were fully vaccinated. The vaccine coverage was almost zero among those aged 0 to 69 years, with only hospital workers and people from other selected professions have been immunized.

If it wasn’t or isn’t herd immunity at their estimate of 33%, what was it?  Seems to be guesses and little data.  But, the researchers must believe herd immunity is a credible hypothesis.  Do they have any observable data to indicate Sweden will achieve herd immunity via the experimental mRNA route?