21st May 2020
Update: Sweden’s pandemic has probably (a little) more distance to go
Email I just sent out to a group of interested persons:
Just thought I’d update since I’d earlier considered Anders Tegnell’s view (that Sweden will achieve herd immunity by end-May) to be broadly in the ballpark, but it now turns out that he was somewhat over-optimistic.
Initial serological studies in Stockholm were probably not random enough. The first comprehensive serological results show Stockholm might have achieved around 20% immunity by now: https://www.thelocal.se/20200520/heres-what-swedens-first-coronavirus-antibody-tests-tell-us – “We are somewhere around 20 percent plus in Stockholm now,” Tegnell told journalists at the press conference.”
I’m not sure about this result, though, which appears too low to me, after four months of relatively unconstrained spread of the infection. I have always believed that there is a significant proportion of people who don’t develop antibodies for this particular virus because they have innate immunity or immunity from previous common cold infections. This proportion doesn’t show up in serological studies.
New ICU admissions suggest that Sweden is almost certainly on the other side of the hump: https://www.icuregswe.org/data–resultat/covid-19-i-svensk-intensivvard/. This suggests that herd immunity is almost there and is hard to reconcile with this serological result.
As expected, Sweden as a whole is behind Stockholm, possibly in the range of 10-14% overall. If there is no innate immunity and this result is robust, then around 5-6 times more people could ultimately die in Sweden – up to 20-25k, overall – which would still make this only a “bad flu” year, not a Spanish flu year. But if there is significant innate immunity, then the final death figure should be much lower.
Sweden’s economy can only get stronger now as people become more willing to revert to full normalcy – latest perhaps by the end of June.
And I remain solidly behind Sweden’s approach as it is the only genuinely scientific approach we are seeing today. It remains the role model for the world also on human rights and liberty. A minor over-estimation by Anders Tegnell hasn’t change my mind about Sweden.