A year is probably going to be more than sufficient. But "we don't know" at this time is the best answer available at this time. It could easily turn out to be 2 years, but the further out that time horizon runs, the better the odds should look for Sweden having made the right decision at the start.
They just said they are giving up the approach and are going to use a new one. In a year you'll see the results of how the new approach performed.
Well, that'll certainly complicate things.
But you do realize that with this virus, the longer the clock remain running, the greater the odds of "get it over with" being the better strategy increases? This does naturally run against the "hedge" of a vaccination strategy bearing fruit in the first year.
The virus spread far enough in Europe and the US by the start of March that the genie was never going back in the bottle. Track and trace can slow it down, but will never fully stop it. Lockdowns at this point have only been shown to slow it down, and unless you want to go full on totalitarian, even that cannot extinguish the virus once established in the population.
The George Floyd Protests are almost certainly going to spike it as well, and we're at the stage where a second lockdown is no longer politically viable. (On both sides)
It will be "interesting" to see just how close we push the needle to the limits of hospital capacity before this concludes. But much of the western world, thanks in no small part to George Floyd, is now likely going to have been better off to have done what Sweden did in the first place, even as Sweden backs away from it.
