2nd Spike - any evidence?

[SoberCurious]

Does anyone have any links to scientific arguments for there being a second peak soon please?

[peonypower]

The US CDC give an IFR of 0.26pct
This is a conservative figure as it assumes an asymptomatic rate of 35pct, when many studies have shown 50-80pct of people are asymptomatic.

IFR is probably around 0.2pct, comparable to a 'bad' flu season

Given variation in testing rates and the ways in which deaths are recorded differing between countries - and even within countries over time - the only true measure of a spike is excess mortality. We have not seen a second spike anywhere as yet.

There is increasing evidence that only 20pct of populations are susceptible as others have T cell immunity or residual immunity from a prior coronavirus infection (aka a cold)
Even on the Diamond Princess, only around a third of passengers and crew caught the virus despite the average age being higher than average and innate and adaptive immunity weakening with age. Care homes will be higher due to the advanced years of their occupants and their depleted immune system. This is why they need protecting (which is the precise opposite of what has been done in the UK and why our excess mortality is so high)

Anyway, in normal healthy young people we are likely at herd immunity in places like London and a second wave is unlikely.

Stop the insanity now.

(And no, I am not a doctor. Many doctors are surprisingly dense, and of the epidemiologists I work with, far too great a proportion have a vested interest in bigging up the panic. Statisticians are the people speaking sense right now - listen to them)

[LilyPond2]

covid.joinzoe.com/post/second-wave-covid
This webinar from Zoe app people has a discussion about the likelihood of a second wave.

[Derbygerbil]

@larrygrylls

You will notice that I used IFR rather than CFR; there is a subtle but important difference. The IFR includes those who become infected but are asymptomatic.

I agree with what you wrote, but to be pedantic, if total deaths in NYC from Covid are 0.26% of the total population, it’s reasonable to assume that the IFR and the CFR are both above 0.2%!

Regarding antibody tests, I’m increasingly thinking this doesn’t tell us nearly as much as I did only a couple of weeks ago, for the reason you give.

Regarding t-cells, I wonder whether they offer a degree of protection rather than immunity... For instance, in a young, healthy person, they might be enough to fight a low infectious dose without the need for antibodies if otherwise well, but wouldn’t be enough if that person was exposed to a high infectious dose and also run down, in much the same way that we’re all more susceptible to colds and other infections when we’re run down. But I’m no immunologist so can’t speak confidently on this.

[Haenow]

Genuine question, what’s the difference between an increase in cases vs a second wave/spike? I would think there is always going to be an increase in cases and people mix somewhat more. I don’t think this can be prevented. As long as it’s not an overwhelming number, it’s natural, surely? Lockdown was to flatten the curve, it was never intended that we’d be on a constantly downward motion.

[larrygrylls]

Derby,

'Although a CFR of 0.2% is almost certainly too low for the population at large ....'

You will notice that I used IFR rather than CFR; there is a subtle but important difference. The IFR includes those who become infected but are asymptomatic.

There are still so many unanswered questions. For instance, are there people who are immune to infection without having specific antibodies? That might mean we can achieve herd immunity based on far fewer antibody-positive tests (as from an epidemiological perspective, if you cannot become infected and transmit on, regardless of reason, you are immune).

I do think that we should err on the side of caution with regard to reopening society but, equally, a gradual reopening seems sensible, as it can always be reversed if necessary.

[pfrench]

I think Israel are seeing an increase in cases

A friend in Israel say that they are particularly seeing raises in cases in young people and school staff. This person is not a member of school staff, so I'm not sure how skewed that bit of information is.

Did anyone look at the tweet I linked about Florida? Opened up, the line has changed. It's not a 'spike', it's a raise in number of cases.

[Derbygerbil]

it’s highly improbable that they have achieved herd immunity

By that I mean complete herd immunity sufficient to stop any more infection in NYC.

[Derbygerbil]

@larrygrylls

Although a CFR of 0.2% is almost certainly too low for the population at large (NYC Covid deaths are 0.26% and although a significant proportion have antibodies, it’s highly improbable that they have achieved herd immunity), the CFR amongst the young is far lower, so yes, a combination of it beginning it’s spread amongst the young and the possible lack of super-spreading events in the early days, could have meant it was here weeks earlier than the earliest reported case... these would be part of the first (and hopefully only) wave though.

[larrygrylls]

Derby,

Yes, that may also be the case.

But if you model a January start, an infectivity rate of, say, 2.5 and an IFR of 0.2, then it will take several weeks for the deaths caused to be statistically significant relative to the normal winter deaths, especially if we were having an unsually 'good' flu season.

[Derbygerbil]

@larrygrylls

I think the fact that transmission seems to occur very spikily is a factor that could explain why it could have been here for a while in relatively small numbers for a while. Most people wouldn’t have infected anyone else, but a few would have infected a lot.... It could conceivably have bubbled
along without any super-spreader events for a few weeks with most infections not propagated. Once a critical mass is reached and thousands are infected, the super-spreading events happen frequently and growth at a population level becomes exponential.

[Derbygerbil]

I think the protests will more likely be the test. The beaches and VE Day celebrations will in truth have been far fewer people than portrayed and done outside with a lot of social distancing. Being close together with lots of vocalising in large crowds was a problem in spreading the first wave.

I agree... A study investigating transmission events identified only one outdoors from more than a hundred indoors, and the outdoor event involved
no social distancing. People don’t bunch together like sardines at “packed beaches” and there’s generally a breeze being next to the sea... and the recent protests saw people outside and generally wearing masks, so the risks are overblown here too.

Since March, we have al generally become hyper-sensitive to social distancing in a way that didn’t even cross our minds beforehand. Take London for instance.... Prior to lockdown there would have been millions getting onto tightly packed trains, buses and tubes daily. I watched a tv show recently and was shocked by how closely packed the audience were in the theatre.... of course,
it was shot months ago and my reaction was ridiculous but it shows how my psyche has changed, and judging from other posts, this is common.... even brushing within 2m of someone for a split second becomes a concern for many. Recent events don’t even come close to how things were pre-lockdown.

We may see a plateauing or possibly even a slight pulse in numbers after recent events, but no second spike anything like the first one.... That doesn’t mean it’s ok to go back completely to how things were before for the reasons I’ve outlined above.

[larrygrylls]

Derby,

To be fair, if Covid arrived earlier but the ifr was much lower than currently thought, you could model infection increasing for quite a few more weeks without a perceptible death rate rise, especially if the initial cases were predominantly young and fit, returning from skiing or business trips abroad.

Which leaves immunity. In the above scenario we should see more immunity than is currently believed. However, I am not sure the current antibody tests are that reliable and there could be innate immunity too.

I think that the jury is still out.

[larrygrylls]

We are nowhere near back to normal and it does look like r has slightly increased. Also, the warm weather does seem to slightly lower the transmission rate.

I doubt we will see a second major spike (soon) as most sensible people are still distancing,

However, a virus does what it does, you cannot politicise it. There are still many unknowns but much is known now.

If we opened up fully tomorrow, cases would start rising exponentially again. Maybe not quite as fast as the first time due to some level of herd immunity and the nice weather, but rise they would to a level where everyone would demand another (hard) lockdown.

Opening up bit by bit and seeing what happens is sensible and, also, optimal economically.

[Derbygerbil]

Or - we are past the second wave. Unless we know when it first came here (which is unlikely unless we retest blood samples/xrays etc) and we get some proper info coming our of China we might never know.

Covid may well have been here earlier than official figures, but given there was no discernible change in deaths above underlying averages prior to March, there was no earlier first wave, or even first ripple for that matter.... Any earlier cases would have been part of a current wave that built
very slowly at first but then exploded from March.

[itsgettingweird]

I agree we've not seen a hide spike from these events but they have had some effect

Can you explain how you know that? We have no way of knowing what would have happened without VE day or BLM protests. I can't think of any way to identify whether there has been an effect and certainly not ot quantify it.

This is very true.

We do know that Italy and Spain had a faster drop off of cases and deaths than us and afaik they had a stricter lockdown and slower opening up.

But I'm also very careful when comparing. We have completely different habitats in our countries and we have far denser areas of population.

[feelingverylazytoday]

I think Israel are seeing an increase in cases uk.reuters.com/article/uk-health-coronavirus-israel/israel-stops-easing-covid-19-restrictions-after-spike-in-new-cases-idUKKBN23F1T2
This could be one to watch.

[Gwynfluff]

I think the protests will more likely be the test. The beaches and VE Day celebrations will in truth have been far fewer people than portrayed and done outside with a lot of social distancing. Being close together with lots of vocalising in large crowds was a problem in spreading the first wave.

[FliesandPies]

BLM has probably set back race relations 20 years by their actions and there will be a backlash.

What kind of backlash do you mean?

[BigChocFrenzy]

"BLM has probably set back race relations 20 years by their actions and there will be a backlash."

Rubbish
Most people, even if not black, understand the anger at watching a police officer brutally murder a helpless prisoner
This was the backlash against that murder and so many hundreds like it in the USA

Racists can always find offence at anything black people do

[pfrench]

Florida

[MsSafina]

These are "the clowns" - I.e. scientific advisors - who told people to socially distance and not go out in large crowds. BLM has probably set back race relations 20 years by their actions and there will be a backlash.

[pfrench]

I can't think of any way to identify whether there has been an effect

Well, we could compare speed of decline in similar countries. But no one can even agree what a similar country would be, and none of the countries who might be similar, carried out lockdowns or whatever in the same way. So, we're all blind.

The science was the right way to go, but our government has sidelined science the whole way along.

[pfrench]

What's annoying* me a bit is that schools have opened up more at the same time as big protests. If we were following science, we would have changed one thing at a time, for a period of time. Ie, schools open up a bit, watch things for a few weeks, open up a bit more etc, but now we won't be able to isolate schools as a cause of increase infection, or not. Which will affect decisions about September, which is what I want to know about.

*I'm not annoyed people are protesting per se, just unfortunate timing.

[TerrapinStation]

I agree we've not seen a hide spike from these events but they have had some effect

Can you explain how you know that? We have no way of knowing what would have happened without VE day or BLM protests. I can't think of any way to identify whether there has been an effect and certainly not ot quantify it.

[palacegirl77]

Or - we are past the second wave. Unless we know when it first came here (which is unlikely unless we retest blood samples/xrays etc) and we get some proper info coming our of China we might never know. But historical cases of pandemics suggest first cases much milder - and less affected, subsequent ones much more deadly. Usually happening 5-6 months after first cases. Just need to see one from Nov/Dec and we would know!