Why Asymptomatic Transmission is Higher in Summer

[ClimbDad]

Here’s a useful explainer on why asymptomatic transmission of respiratory viruses is higher in summer and why symptomatic transmission and mortality is lower.

Prepare for a second wave. If schools are to open with normal class sizes, students and teachers must wear masks.

Your threads always cheer me up @ClimbDad

Is this the 5th or 6th "second wave" we've had to prepare for? I've lost count.

I think it's pretty obvious that we are going to have more respiratory viruses in the winter. Just the fact that we will have people with flu being admitted to hospital at the same time as people with Covid, and that we won't know which are which, is going to lead to people with flu being exposed to Covid. The amount of people with Covid symptoms is going to place massive stress on testing facilities, even if the vast majority of them are not Covid. If testing cannot keep up with demand, this is going to lead to Covid cases being missed. None of this is debatable, winter is going to suck, and being sarcastic to people who are trying to issue warnings will not change this.

The thing about Covid is that WE are in control of it. We beat it by limiting our contact with others. To persuade people to do that, those people need to understand that limiting contact is necessary. People who are issuing warnings are not doing it out of glee, or out of some ghastly love of death, but for the exact opposite reason. They want to limit deaths and the long term effects of the virus.

You may believe that the mental health cost, or the economic cost, outweigh the health risk of Covid and your opinion is as valid as anyone else's. But when you insult or belittle people with the opposing opinion, you are feeding into a combative culture of othering that worries me as much as either Covid or lockdown.

If we were going to have a second wave then surely it would have happened by now given that we have had protests, crowded beaches etc. These endless proclamations of second waves by some makes me think that certain people will not be satisfied until it happens and then they can comment with a "told you so". Also more people now will stay at home if they feel unwell and masks will continue to be worn, thus reducing the spread of viruses. That, along with the flu jab being available to those over 50 who previously had to pay for it means more will be protected, again reducing the spread.
By all means worry about it if you want but telling people to "prepare for a second wave" when they can't possibly know for sure just feeds into the scaremongering and there has been quite enough of that already.

"If we were going to have a second wave then surely it would have happened by now given that we have had protests, crowded beaches etc."

But those took place outdoors and we now know that outdoors = much lower risk. In the US it took about 2 months from reopening for there to be a significant rise in cases and the most likely reasons are thought to be because of spread in places like bars and restaurants etc.

Indoors, crowded, lack of ventilation (or possibly because of ventilation, air conditioning for example) people talking, especially if loudly, shouting, singing all means increased risk.

If we were going to have a second wave then surely it would have happened by now given that we have had protests, crowded beaches etc.

When you’re sitting on a crowded beach, you’re unlikely to be less than 2m away from others. Include sea breezes and the risk of transmission would be very low.

As for the protests, they were outside too; a higher risk but only a few hundred rioted.

Back in March, tens of millions of people had frequent, often lengthy, non-socially distanced encounters, indoors, daily - a completely different ballgame.

@nellodee

I think it's pretty obvious that we are going to have more respiratory viruses in the winter. Just the fact that we will have people with flu being admitted to hospital at the same time as people with Covid, and that we won't know which are which, is going to lead to people with flu being exposed to Covid. The amount of people with Covid symptoms is going to place massive stress on testing facilities, even if the vast majority of them are not Covid. If testing cannot keep up with demand, this is going to lead to Covid cases being missed. None of this is debatable, winter is going to suck, and being sarcastic to people who are trying to issue warnings will not change this.

The thing about Covid is that WE are in control of it. We beat it by limiting our contact with others. To persuade people to do that, those people need to understand that limiting contact is necessary. People who are issuing warnings are not doing it out of glee, or out of some ghastly love of death, but for the exact opposite reason. They want to limit deaths and the long term effects of the virus.

You may believe that the mental health cost, or the economic cost, outweigh the health risk of Covid and your opinion is as valid as anyone else's. But when you insult or belittle people with the opposing opinion, you are feeding into a combative culture of othering that worries me as much as either Covid or lockdown.

I agree with some of your post, I don't agree with all of it.

For example

They want to limit deaths and the long term effects of the virus.
whilst I agree that may be the aim - I think there will be more deaths in the future related to the economy and mental health issues than directly from Covid. And I think the countries children will have far more long term effects from the lockdown and missing education especially, but not limited to, children in neglectful and abusive families.

I am also hopeful that there will actually be fewer deaths this winter from respiratory infections as many of the people who would have died with the flu later this year and early next, died in the Covid pandemic. I hope I'm right but I am very aware that there is no guarantee this will be the case

Like you though I believe insulting and belittling people only has negative effects for both sides.

Do you ever give it a rest OP another depressing 2nd wave post off you !!!no one knows what will happen in the future so give it a rest

Ahh thanks OP, a bit of cheerful bedtime reading to ensure sweet dreams and peaceful slumber

@IAintentDead totally agree

@DebLou47

Do you ever give it a rest OP another depressing 2nd wave post off you !!!no one knows what will happen in the future so give it a rest

Betting against a second wave is like betting against the sun not coming out tomorrow. There will be a spike in transmission in winter. The only question is how large it will be. That will be determined by our behaviour. Put hundreds of thousands of children in school without masks and expect the hospital wards to fill up.

Virologists where I live - Germany - have said that most countries in Europe have a good chance of avoiding a fullblown 2nd wave
if government take sensible decisions and most of the public are compliant

So, let's do our best to avoid a 2nd wave - there seems a good chance that we can just restrict the winter increase to local outbreaks which can be squashed by local lockdowns,
plus maybe some additional targeted measures in the country as a whole, to keep down community spread.

You can always rely on BigChoc for a level headed post!

Schools need to reopen. The situation we had in March and April is not sustainable. Life can't stop indefinitely for a virus.

If we were going to have a second wave then surely it would have happened by now given that we have had protests, crowded beaches etc.

I take it you don't understand exponential growth then.

Maybe if we didn't have warnings of a 2nd wave that doesn't happen every 5 minutes people might not be thinking " yeah, right " but we've not had the VE day spike, the BLM spike, the beaches spike, the shops spike, the pubs spike and I'm sure I've missed a few other non-existent spikes.

Of the last 10 respiratory virus pandemics I understand that 5 have had a second wave? So not all, it's not a certainty. I appreciate there is still a significant proportion of the population susceptible to the virus however we are much better prepared now than we were in Feb/March.

I'm afraid I pretty much disregard anyone who says that any particular thing will definitely happen when it comes to this pandemic. No one knows anything for definite. Likely perhaps, but not definite. It suggests that a person's thinking is quite fixed in one direction.

Germany seem to have done a pretty good job, if they think a second wave can be avoided then it probably can. Whether it will be remains to be seen. We do have to take steps to actually live though, if things take a turn for the worse then we pull back.

We already have hotspots in the midlands, north west and Yorkshire. But the media is largely ignoring them because they're nowhere near London, so they don't matter.

Our area of the country has a low level of cases. We had at least a couple of weeks with none, but it is starting to creep up now and we will keep an eye on it.

Both my husband and I are in the vulnerable group and we won't be going on holiday or the pub just yet.

To be honest our main source of infection is probably our daughter. She is a single parent with small children and wanted to be in a bubble with us. We didn't feel like we could refuse. The children have been back at school since May and my daughter is now socialising more, although I think she is social distancing. Her ex is now getting unsupervised contact and the children have already met his girlfriend. We do a fair amount of childcare now that it is the school holidays. I feel a bit stressed by it all as the routes of infection are increasing for us. If cases in the community get too high we may have to make some difficult decisions.

When I mean it's crept up, I mean that cases have tripled in a week.

@Pelleas

We already have hotspots in the midlands, north west and Yorkshire. But the media is largely ignoring them because they're nowhere near London, so they don't matter.

Really? I’ve seen plenty about it in the press myself. And London hardly features in the news these days as it has such a low case level.

if government take sensible decisions

Ah, right-we should be fine then, their track record so far is excellent!

That's another thing, don't trust this government as far as I can throw them. I will not be using their guidelines to keep myself safe because that's not what they are for. They've taken a gamble in order to save the economy and I'm not sure it's going to pay off, for people's lives or the economy.

Thanks for posting this OP, it makes sense to me and there is also a blog:
oldwivesandvirologists.blog/

When people hear, "exponential growth", they confuse it for rapid growth. Exponential growth can be slow. In fact, that's what we're seeing in the UK now. An R0 of 1.1 is still exponential growth. It just means the case doubling time will be 3 weeks instead of 3 days. It seems pretty clear from the official figures the R0 is hovering above 1.

The lowest 7-day average daily rate of infection since lockdown was 545 cases on July 8th. It has been climbining steadily since then and is now 662. When it gets to a daily average of 1,090 cases, that will give the approximate doubling rate. As the number of cases rises, we would expect doubling to accelerate.

Seasonal attenuation means transmission is likely higher than is being recorded, because there will be a larger proportion of asymptomatic transmission, but let's use the official figures and assume the doubling rate is roughly 3 weeks with no acceleration.

July 8th - 545 cases per day (CPD)
July 29th - 1,090 CPD
August 19th - 2,180 CPD
September 9th - 4,360 CPD
September 30th - 8,720 CPD
October 21st - 17,440 CPD

and so on. Nothing has to change. The virus just needs to keep spreading at its currently seemingly low rate and we will see a second wave, with a large number of cases at the end of October. Add schools into the mix, and even if they only make a 20% contribution to the growth rate, we will see a signficant acceleration in infection. If seasonal attenuation is a factor with the SARS-CoV-2 virus, the numbers will be even worse.

There are those on MN who believe they can solve the pandemic through wishful thinking. If they succeed, I hope they'll use positive vibes to cure malaria next

I'd rather put my faith in science and public health measures that are proven to work. Children and teachers need to wear masks in school, class sizes need to be reduced as much as possible, and people need to take whatever steps they can to reduce transmission by minimising social contact.