Did Sweden achieve herd immunity without lockdown ? Nej, they did lockdown unofficially
While the neighboring countries were entering the lockdown, Sweden decided not to implement lockdown and tried to achieve herd immunity. Swedish government kept economy running with the casual level of infection control and attempted to protect the economy as much as possible. On 3rd June, the argument over Swedish way suddenly ended when Sweden’s top epidemiologist admitted his strategy to fight Covid-19 caused too many deaths. Without San Marino and Andorra, Sweden is ranked to be the 6th worst country in deaths per capita.
However, Sweden had its GDP contracted by only 9% in the second quarter while UK had the historic plunge of GDP by 20% in the same period of time. Besides, the new cases seem tamed in Sweden where other European countries are suffering the resurge of the new cases. They say Sweden successfully achieved herd immunity. Is that so ?
The hint is in Google mobility reports again. This is the GPS tracking data collected by Google to show how many people visited the places categorized in 6 zones, which are retail area, grocery stores, parks, workplace, transit stations and residential area. Google is publishing this data for free so we can analyze how mobility affected Covid-19 spread.
The line chart above shows the mobility comparison of transit stations in Sweden (red) and Norway (blue) (5-day rolling average). Norway chose a typical lockdown policy and successfully protected the human lives and its economy. It looks like Norway had a sharp drop of mobility in transit stations from March to April. This is obviously due to the lockdown. However, interestingly, the mobility is also dropping in Sweden at almost the same timing. There is still 10~20% gap between Norway and Sweden, but Sweden had even the lower mobility in June, when its top epidemiologist admitted his mistake.
The line chart above represents the mobility comparison of workplaces in Sweden (red) and Norway (blue) (5-day rolling average). We see the same pattern as transit stations here. Norway had a mobility plunge from March to April, but Sweden also had a mobility drop as following Norway. They had a lower mobility in June than Norway. After all, Swedish practically implemented unofficial lockdown without the strict order from the government.
This is the daily new deaths per million population in Sweden (red) and Norway (blue). The difference between Sweden and Norway is clear enough, but it seems decreasing in Sweden as well. Maybe this is due to the 20% gap from Norway. If Sweden decided to implement the official lockdown, this didn’t have to happen probably. However what stopped it going any worse was the rational decisions of each citizen in Sweden.
Google mobility reports : https://www.google.com/covid19/mobility/?hl=en
New deaths per million population data : https://github.com/owid/covid-19-data/tree/master/public/data