3 ms·

> I can't help but wondering if the unlimited outside time under the guise of "exercise", but which people are clearly taking advantage of by going to hang out

> I can't help but wondering if the unlimited outside time under the guise of "exercise", but which people are clearly taking advantage of by going to hang out with friends in the park, has anything to do with it. Or perhaps it's the lack of masks in indoor areas like grocery stores that has prevented a bigger drop (in SF, only starting today has that finally changed). Unlikely to both. Outdoor transmission is rare and I'd question if grocery store transmission (with heavy amounts of social distancing) is common given other countries historically being able to trace the majority of covid infection sources. First off, as you allude to lockdowns are less effective than you think - we managed in norcal to drop from 1.43 to 0.98 (https://www.medrxiv.org/content/10.1101/2020.04.12.20062943v1.full.pdf https://www.medrxiv.org/content/10.1101/2020.04.12.20062943v...). Which is really good (uncontained to contained) in one sense, but shows you how slow containment is. The containment difficulties lie in: 1. Household transmission still takes place after lockdown. 2. Huge variances within population sub-groups. R within folks with little human contact (WFH, etc.) was probably barely above 1 before the lockdown -- essential workers with heavy human contact already had the highest R and because they are still working (i.e. not really locked down), still have an R > 1 for quite some time. 3. Essential workers tend to live with other essential workers -- creating a multiple generation transmission chain (#1 and #2) 4. Group living outbreaks (symptoms of #3). e.g. in Santa Clara county, nursing homes are becoming a larger percentage of new cases over time. Something like 20% of new cases in the last 2 weeks. A single homeless shelter in SF is responsible for 20% of cases in the last 2 weeks. 5. At some point, you just are going to reach some level of herd immunity within the most susceptible groups -- in a sense the lockdown is more of a quarantining of a large percent of the population and letting everyone else get herd immunity. CA definitely has high urgency in increasing testing - honestly, if you just hired a bunch of people to contact trace, you could probably go back to the March 15 pre-SIP world now.

cactus2093 7y ago
All good points, I’ve wondered about the differences between different groups as well as far as herd immunity. Haven’t heard it discussed much, maybe because it’s super problematic to explicitly call that a plan - let’s let the working class all get it, and then everyone else can go back to normal. How was the reproductive rate 1.5 before the lockdown though? The latest estimates I’ve seen put R0 at 5.7.
- usaar333 7y ago
  I'm not the first person to have thought about group variations. :) Here's an old paper (which also highlights how this important fact is omitted in a lot of analysis): http://web.eve.ucdavis.edu/sschreiber/reprints/Moving_beyond_averages.pdf http://web.eve.ucdavis.edu/sschreiber/reprints/Moving_beyond... R0 is before interventions AND is environmentally related. Wuhan & NYC covid has way higher R0 than California Covid because of higher density/public transit usage. Additionally, effective R was already well below R0 by the first week of march (pre-lockdown) because of heavy (mostly voluntary) measures already in place. (WFH, more washing of hands, avoidance of mass gatherings, etc.) Finally, I'm speaking a bit tongue-in-cheek calling it the "essential worker herd immunity plan". I doubt public health officials, rushing to do something, explicitly realized this would happen -- but with a bit of thought [1], it was a pretty expected outcome. [sort of how nursing home outbreaks occurring when we didn't - and still don't -- quarantine employee or give them heavy PPE was expected) [1] It's pretty unfortunate there isn't a public or academic comment period to evaluate the SIP orders (after issuance) and almost no useful data being given about cases. There's a lot that doesn't make a lot of sense -- important restrictions missing and unnecessary restrictions present. My biggest pet peeve is allowing babysitters to come to any workers' houses, but it being disallowed to send your kid to a babbysitter's house, when adults are more likely to transmit than children.

cactus2093 7y ago

All good points, I’ve wondered about the differences between different groups as well as far as herd immunity. Haven’t heard it discussed much, maybe because it’s super problematic to explicitly call that a plan - let’s let the working class all get it, and then everyone else can go back to normal. How was the reproductive rate 1.5 before the lockdown though? The latest estimates I’ve seen put R0 at 5.7.

usaar333 7y ago
I'm not the first person to have thought about group variations. :) Here's an old paper (which also highlights how this important fact is omitted in a lot of analysis): http://web.eve.ucdavis.edu/sschreiber/reprints/Moving_beyond_averages.pdf http://web.eve.ucdavis.edu/sschreiber/reprints/Moving_beyond... R0 is before interventions AND is environmentally related. Wuhan & NYC covid has way higher R0 than California Covid because of higher density/public transit usage. Additionally, effective R was already well below R0 by the first week of march (pre-lockdown) because of heavy (mostly voluntary) measures already in place. (WFH, more washing of hands, avoidance of mass gatherings, etc.) Finally, I'm speaking a bit tongue-in-cheek calling it the "essential worker herd immunity plan". I doubt public health officials, rushing to do something, explicitly realized this would happen -- but with a bit of thought [1], it was a pretty expected outcome. [sort of how nursing home outbreaks occurring when we didn't - and still don't -- quarantine employee or give them heavy PPE was expected) [1] It's pretty unfortunate there isn't a public or academic comment period to evaluate the SIP orders (after issuance) and almost no useful data being given about cases. There's a lot that doesn't make a lot of sense -- important restrictions missing and unnecessary restrictions present. My biggest pet peeve is allowing babysitters to come to any workers' houses, but it being disallowed to send your kid to a babbysitter's house, when adults are more likely to transmit than children.