Coronavirus 2nd Wave?

[Octavious]

Is there any evidence that there is one yet?

The US national figures on the face of it show a second wave, but looking closer at the figures it seems more like the first wave hitting other parts of the country. New York took an early and significant hit, but has been largely Covid free for some time.

You get a similar picture in London, which is currently enduring a Covid death rate of 2 or 3 a week (which, to provide some perspective, is far lower than the 70+ per week who die from poor air quality, and are approximately similar to traffic deaths).

There's lots of talk about Australia having a second wave, but it didn't really have a first wave to speak of. Are there any regions that had a significant first wave that are now having a significant 2nd wave?

[orathaic]

I mean, surely we should be looking at China, Korea, Japan and Italy. Given that their early 1st wave examples were useful for informing us.

I haven't looked at the data. But yes, that sounds realistic.

In 1918/19 some cites had two waves, others only had one. Others had 3, I think. I presume depending on how they implemented containment.

[orathaic]

This rather simplified video gives some info https://youtu.be/MiOx8VgcQS0
can't find anything better right now (I say simplified because looking at only two cities and limited information, makes for a very simple conclusion...)

[Randomizer]

I think China is considered to be on its second wave, but differentiating is hard because most places are just facing spikes in their first wave due to lifting restrictions.

[Octavious]

The Chinese first wave was remarkably localised, though. You're getting a number of cases in Hong Kong, but they didn't have a first wave to speak of.

I'm rather more interested in looking at New York, London, and Sweden to be honest. The virus here has largely disappeared. New York has not implemented measures significantly more stringent than many of the other places in the USA in which the virus has a strong first wave of cases, and yet the impact virus in New York now is extremely low. Sweden has implemented a far less severe response to the virus than most of Europe, and yet it has come and mostly gone.

There's a mystery here which is really quite important. Why hasn't the virus continued to make hay in these locations? It looks very much as if herd immunity has been achieved, yet all the studies I've seen referring to antibodies suggest not. Are the studies wrong? Is the assumption that you you need antibodies in 60+% of the population wildly off? Is there something else at play?

[flash2015]

I was wondering if it is somewhat still weather related. Why is it hitting places like Florida/Texas/Arizona now instead of in April? My hypothesis - The warm weather in the north gets people outside which is less risky, the hot summer down south gets people crowded indoor in air conditioned places which is more risky.

[orathaic]

Interestung idea flash.

Temp definitely has an effect. It is also possible that humidity greatly affects how long the virus takes to die in the air (or how long it takes for the virus capsule to dehydrate and render the viral code inert).

But I would literally be grasping at straws trying to figure this out. Are there not serious epidemiologists working on these questions?

[Randomizer]

It's the difference between laboratory and real world behavior. Outside under UV light and hotter temperatures the virus lasts a shorter time, but when people are inside it doesn't matter what is going on outside. Inside the virus can spread because the indoor temperature is colder and people are closer together.

This is why Trump runs away in panic when someone sneezes or coughs in a room.

[peterlund]

This is why Trump runs away in panic when someone sneezes or coughs in a room.

Maybe his brother died in covid, don't know. But it would explain why he suddenly seems to take it seriously...

[peterlund]

There's a mystery here which is really quite important. Why hasn't the virus continued to make hay in these locations? It looks very much as if herd immunity has been achieved, yet all the studies I've seen referring to antibodies suggest not. Are the studies wrong? Is the assumption that you you need antibodies in 60+% of the population wildly off? Is there something else at play?

It surprised us as well that only some 17% had antibodies here in Stockholm (I, my wife and daughter tested negative last month too). But still the spread has gone down significantly.

Experts think it probably has to do with T-cell immunity that does not show up on the antibody tests. In small studies the number of people with T-cell immunity was twice as large as those with antibodies. If that is the case, our 17% would turn into 51% immunity in Stockholm.

[orathaic]

Saw some good research on humidity, and how the virus hangs around more in the air when it is less humid. So the summer has generally been good for reducing the R number. And things like air conditioning or indoor heating (which typically reduce humidity) will increase the spread during the northern hemisphere's coming winter.

So yeah, we may yet see a second wave.