However, state epidemiologist Anders Tegnell said the study, carried out for the Public Health Agency, does not mean Sweden needs radically to change its strategy.
The strategy has never been to achieve a certain level of immunity... Our strategy has always been to keep the level of spread on a level that is so low that it does not affect society or healthcare in any catastrophic way and that has been achieved. Knowing the level of immunity has more to do about, OK, what do we need to continue doing and what do we need to add to become even better after the summer"
The rate of immunity is increasing substantially over time, Tegnell said, but it is also clear that the elderly have significantly lower levels of immunity than the rest of the population, and that, he said, would suggest the elderly have indeed been more isolated and hence more protected from the disease.
Another study on ongoing covid-19 infections indicates the peak has passed, Tegnell added.
Press play to hear more about the two studies and Tegnell's comments.