Logic behind second wave prediction

[BumbleWumble]

What is the actual logic behind the prediction that there will be a second wave?

I know it's based on what happened with the Spanish Flu but wasn't that influenced by soldiers returning from. WW1?

Why would this virus just take a break so to speak before returning with a vengeance? As opposed to simply carrying on infecting people consistently whereever it can.

It is not clear how long immunity will last in mild cases. It could start spreading again in a few months even in areas that have achieved herd immunity:
www.nature.com/articles/d41586-020-01989-z
'Because there is not yet a clear, measurable marker in the body that correlates with long-term immunity, researchers must piece together the patchwork of immune responses and compare it with responses to infections with other viruses to estimate how durable protection might be. Studiesof other coronaviruses suggest that ‘sterilizing immunity’, which prevents infection, might last for only a matter of months. But protective immunity, which can prevent or ease symptoms, could last longer than that, says Shane Crotty, a virologist at the La Jolla Institute of Immunology in California'

A scientist on R4 said lockdown is like putting the virus in the freezer only to come back after, then you have Tam’s suppresses spring.

The second wave is more to do with exponential growth and restarting that.

I don’t know where we are with how many in the population who have had it, also since the peak seems to time with just before lockdown SD in place now may still help.

How does a virus "burn itself out"?

"How does a virus "burn itself out"?"

By infecting everyone (realistic worst estimate of 60% of UK infected is 500,000 deaths.

This is the natural approach to herd immunity. If immunity from this disease is brief, then epidemics every year or so.

If enduring, then it becomes (like measles before vaccination) a disease of childhood, because new non-immune people keep getting born, and when there are enough of them, it'll sweep round again.

It's an approach that has a terribly human cost, not just from Covid but from everything else as health services cannot continue (too many sick HCPs, too mant patients with other conditions dying too because they are weakened and hospitals unsafe)

The severity of this disease appears to be related to the amount of virus at exposure. (Maybe, still so much unknown, but this is a working hypothesis behind why HCPs become so severely unwell)

There are numerous papers showing that it transmits more weakly in warm, sunny conditions - so viral load at transmission lower, disease milder?

Also more than one strain - one somewhat less severe than the other. You might just be luckier which one is in circulating in your region.

All bets are off for the winter - when viruses typically circulate more freely, and when the protective effect of hot weather has gone, and when people will be less inclined to socialise outdoors.

The only things we can do are
a) wash hands frequently
b) wear masks to protect others
c) ensure that coughs and sneeze are contained, and used tissues binned
d) - the most important - do not lose the habit of social distancing. Minimum 2m away from strangers, unless you have to get closer, in which case mask/visor, and wash afterwards

@nether
I agree. Some people need to have this reinforced to make failure to adhere socially unacceptable. I still remember with disgust watching a woman walk out of the loos in Sainsbury’s without washing her hands just a couple of days before lockdown and think we all have to behave much more responsibly for the foreseeable future.

If this does become endemic and people do lose immunity after a few months, then without a vaccine the future for humanity is extremely bleak indeed. It'll just go on and on. People who have had it once and been left not 100% will then face getting it again and incurring more physical damage. Or you might survive it one time only for it to come back round and kill you the next time. Life will just be a socially distanced misery of continually trying, and failing as a population overall, to avoid it.

I don't think that Melbourne is experiencing a 'second wave' just because they have locked down, it's just a very cautious approach to a relatively low number of cases, similar to China.

USA didn't open up too soon, they put in measures far too soon in the majority of the country when only one state was near its peak, now that they have released measures lo and behold their other populous states are heading for their peaks.

I think that we will manage this over the course of the winter. Probably a lot more people will die than in a usual winter - though possibly not as so many have already died. Local lockdowns but extremely low chance of national lockdown or nationwide school closures - it is simply a measure that we can no longer afford to take financially or otherwise. It will likely be fairly chaotic and reasonably risky, but surely most people can see that we must keep everything running as much as we possibly can?

Sweden hasn't locked down though and they have peaked

A big chunk of the population in Sweden stopped doing stuff though. They voluntarily put themselves away for a bit. It only takes 60% of the population to start socially distancing or whatever, to flatten curves and so on. Friends were talking about shops closing due to lack of footfall in Stockholm, and even though there are photos of bars and cafes with people in them, it was mostly young folk. Lots of people were working from home through choice. They've still had a peak of deaths, they've still had a big economic hit. By doing an official lockdown, the government had to support things financially.

@BumbleWumble

What is the actual logic behind the prediction that there will be a second wave?

I know it's based on what happened with the Spanish Flu but wasn't that influenced by soldiers returning from. WW1?

Why would this virus just take a break so to speak before returning with a vengeance? As opposed to simply carrying on infecting people consistently whereever it can.

There isn't any. It's based on modelling that uses a lot of guesses based on what has happened before but life is very different now and this virus is not flu so why should it behave like flu. Yes there are likely to be more cases again in the winter and probably futures winters but it is no longer a 'novel' virus. We may not have full immunity but we will have some.

Fit and healthy people are mostly not at risk, the few young ones that have been badly affected or died are a tragedy, but that happens every year with other illnesses.

Wash your hands regularly, avoid touching your face. Eat healthily and make sure you get enough Vitamin D and get on with life.

Anyone of us could drop dead from a burst aneurysm tomorrow or be involved in a car crash. We can waste our life worrying OR we can live until we die. I know which my choice is.

@Tfoot75 - if lockdowns "aren't a measure that we can afford to take", then we individually have to accept that our nearest and dearest could form part of the collateral damage. That might be easier for some people than others.

Additionally, many people are now reporting long-term issues with covid, and often these individuals were previously fit and well. They're also part of the collateral damage.

@blueangel1 agreed. France have already come out and said that a second general lockdown is not an option, I fully expect that our plan is the same. Collateral damage is something we're all going to have to live with.

@peonypower

Sweden hasn't locked down though and they have peaked (well, deaths are in decline). So it does seem like there is a saturation rate. Our death rate is higher than theirs so I am inclined to think that we won't get a second wave. But somewhere that hasn't had a proper first wave is still at risk of a second if they don't protect the elderly sufficiently.

This is not really based on anything though, just a hope.

[quote blueangel1]@Tfoot75 - if lockdowns "aren't a measure that we can afford to take", then we individually have to accept that our nearest and dearest could form part of the collateral damage. That might be easier for some people than others.

Additionally, many people are now reporting long-term issues with covid, and often these individuals were previously fit and well. They're also part of the collateral damage.[/quote]
I fear that in the absence of a vaccine or effective treatment the collateral damage is going to accumulate to levels we just can't imagine at the moment. Already 60k deaths is bad enough. How many more? And how many people ending up incapacitated permanently? There would be no end to it, it would just cause ever more damage at both the individual and societal level.

I fear that in the absence of a vaccine or effective treatment the collateral damage is going to accumulate to levels we just can't imagine at the moment. Already 60k deaths is bad enough. How many more? And how many people ending up incapacitated permanently? There would be no end to it, it would just cause ever more damage at both the individual and societal level.

Q: What can you personally do about this?

A: You can do your part by observing social distancing and hand hygiene, while maintaining as much engagement in normal life and contact with friends and family as you safely can.

However, the biggest impact on your personal quality of life at the moment would be to stop thinking of end of the world scenarios and concentrate on the little things you can do which make your experience of life better.

It is safe to meet your family in the garden. It is safe to go for a walk with a friend and share a take-away coffee sitting on opposite ends of a bench. And it would be a really good idea for you to get help with your anxiety. It is that, rather than COVID-19, which is currently having the biggest impact on your quality of life.

Any second wave is likely to have a lower death rate than the first wave because, bluntly, many of the most frail people have already died in the first wave.

However even a lower death rate could still be pretty high, plus there will be the “survived but damaged” as is becoming increasingly clear.

On the other hand a second general lockdown would cause huge amounts of damage in itself (on top of the damage already caused by the first wave).

It’s a truly hideous problem.

"How does a virus "burn itself out"?"

By infecting everyone (realistic worst estimate of 60% of UK infected is 500,000 deaths.

One addition to the comment above - a virus burns itself out by infecting everyone it can infect.

We do not know the size of susceptible population for COVID. It may be 100%, it may be less or much less. The actual percentage might depend on age, ethnicity, sex, nutrition or other factors.

The 500,000 deaths estimate was based on 80% of the population being infected (assuming equal susceptibility).

For the love of God, do you not listen and pay heed to anything anyone says or writes on here? This constant catastrophising and melodrama is not only getting very old quickly, it’s not fair to upset other people who may only just getting a lid on their own anxiety.

Unless you know something no one else in the world doesn’t, why would you think this won’t come to an end the same as EVERY OTHER PANDEMIC in human history? More people will die and of course that’s sad but people die all the time of lots of things. It doesn’t stop us living meantime.

It burns itself out if more than (1-(1/R0)) of the population or 1-(1/3)= 67% of the population get lasting immunity because this keeps the R below 1.

Problem is, it seems likely most people don’t develop lasting immunity.

Qasd
...
-we do have a test and trace system, it may not be perfect but we didn’t even test people with symptoms back in March! Every week 100000 people are being told to isolate because they could spread covid, 100000 people who were not told so in March....

I am sorry but where do you live?
Having Ordinary Joe call up people and ask them to pls isolate if you can is not a track and trace.
TTR would be:

• identify ALL contacts
• follow up on ALL
• TEST THEM
• Follow up: do they develop symptoms, etc
• Publish statistics for LAs to act upon in near-real time

What we have is a lot of money thrown at something that doesn't deliver ANY REAL RESULTS. It does line some friend's pockets nicely though

@FizzFan

For the love of God, do you not listen and pay heed to anything anyone says or writes on here? This constant catastrophising and melodrama is not only getting very old quickly, it’s not fair to upset other people who may only just getting a lid on their own anxiety.

Unless you know something no one else in the world doesn’t, why would you think this won’t come to an end the same as EVERY OTHER PANDEMIC in human history? More people will die and of course that’s sad but people die all the time of lots of things. It doesn’t stop us living meantime.

Could you pls give examples of what every other pandemic came to an end by themselves?

Could you pls give examples of what every other pandemic came to an end by themselves?

Er, all of them or else we'd still be experiencing many thousands of deaths from them?

TrustTheGeneGenie
They didn't just end by themselves. Isolation/quarantine stopped the spread or vaccines/treatments stop outbreaks.
Neither are "natural" ends.

Could you pls give examples of what every other pandemic came to an end by themselves?

Go and look it up. I’m not here to educate you.

And I didn’t say “came to an end by themselves”. They still “came to an end”. Otherwise we’d have been social distancing since Spanish flu.