In country after country, 12 days after lockdown the rate of new infections falls decisively. By Joanne Nova. Follow the empirical evidence.
Some people don’t seem to realize that the only reason the daily growth of infections is slowing anywhere, is thanks to drastic quarantine measures or changes in human behaviour.
We can see this in graphs from Italy, Spain, Norway, South Korea, Switzerland, Germany, and China, but not in Sweden or Brazil where there’s not much quarantine and not much slowing of growth curves either.
In all of the former, the big meaningful actions were followed around 12 days later by an obvious slow down.
Australia’s infection rate slowed again last night — presumably due to the increased lockdown measures that were taken two weeks ago:
The timeline of quarantine moves was incremental but most Covid cases were related to flights and cruise ships, so the border changes would have been more influential. And flights were banned from Iran on March 1, South Korea on March 5, Italy on March 11. On 13th March all gatherings over 500 were banned. On 15th March all incoming travellers were asked to self isolate for 14 days. On 20th March all borders were closed. On 21st March social distancing rules of 4 m2 per person were introduced. March 23 saw the closure of most cinemas, nightclubs, pubs, casinos. Restaurants ordered to do “Takeaway only”. Schools closed in Victoria from March 24, but parents were withdrawing children across the country even though other schools were technically open.
The peak on March 22 may have related to the reduction in flights from Italy 11 days earlier, though the Ruby Princess Cruise ship adds a lot of noise. I’m not convinced this is an easy peak to tie to any day, but the major action in Australia was in the middle two weeks of March.
On Feb 18th patient #31 went to religious meetings and cases escalated. By Feb 20th the streets of Daegu were empty. South Korean officials tracked and isolated cases at military bases, at the church group, and one hospital. Interviews were done on, wow, 230,000 members of the church at the centre of the outbreak which accounted for 60% of the national cases. The outbreak peaked by March 3rd, 12 days after the streets of Daegu were emptied.
The growth of new daily cases peaked on March 21, 11 days after the mass lockdown began.
Mass lockdowns were announced on March 15: “Norway takes most far-reaching measures ever experienced in peacetime over coronavirus”.
… and new daily cases peaked 12 days later on March 27th
The Spanish government imposes a nationwide lockdown on March 14th. Shops and businesses closed and all residents asked to stay home on March 15th. A State of Alarm was declared. In Spain cases peaked March 26th — 12 days after the lockdown was imposed.
On the 6th March Switzerland changed strategy to protect older person and vulnerable groups … decisive moves were either to isolate vulnerable people on March 6th or closing schools on March 13. The peak was around March 20.
In Sweden there’s been no organised quarantine, just partial voluntary withdrawal, and there’s also been no peak yet.
In Brazil, President Bolsonaro seems to favour doing nothing, but the governors of Sao Paulo and Rio De Janeiro banned gatherings and closed schools and many are pleading for action.
Hopefully the people still arguing for “flatten the curve” or “herd immunity” will take note of this evidence. Follow option 3 instead: crush the curve.