What exactly does ''more transmittable' mean?

[SlightlyJaded]

I mean, I know that it means it spreads more easily and more quickly.

But how? Is it airborne? Does it live longer on surfaces? Do droplets hold the virus for longer? Or is it just more potent meaning that the viral load is higher and we are more likely to be infected? And if the latter, doesn't that mean it would be a more dangerous strain in terms of impact once caught? (a fact that is currently being denied).

Can someone explain please? Trying not to panic/spiral, but will if necessary!

From what I understand, the spike protein is more easily able to get into your cells. Not that I am a scientist or have any knowledge. I’d read something like that somewhere - it’s to do with be able to more easily take hold of you, as opposed to being ‘more airborne’ etc ...
(Happy to be stand corrected. I too have no idea really!)

Good question @SlightlyJaded

Dee1975. That’s also my understanding of it.

I think this is an excellent question, and it’s something I’ve been wondering too.

They keep saying more transmissible, but unless they qualify how and under what circumstances it’s too vague a statement to be useful, really.

They’ve also been very careful to not say ‘more infectious’ which would suggest that there’s a difference between transmissibility and infectiousness.

I feel that if there was a significant additional risk there would have been changes to the advice given, which there hasn’t been.

@Dee1975 that’s my understanding too. I think it’s ACE2 receptors that are the key and it’s attaching itself to those in a better way.

Just to add that all the evidence is that your individual response would be the same, so if you were always going to be asymptomatic you still would be. It’s just a shame they haven’t identified why some people are or aren’t!

I think I read somewhere it can take hold more readily in upper respiratory tract but can’t remember where!

It would be great if it was following the more transmissible but less nasty mutation trend but I think it’s too early to know. Plus hospital admissions are increasing 😢

So if it binds more easily/better to these ? ACE receptors why doesn't this result in a more severe illness ?

And if the virus is more efficient at this binding business is it the case that less exposure ( less time spent with an infected person ,greater distance from infected person ,fewer droplets falling on you ) results in you contracting it ?

Do we need to be further away and wearing thicker masks than we have been doing ??

(I know we don't know much about the new strain yet and are waiting to find out many things )

My understanding is that you can catch covid from a lower amount of the coronavirus than before.

Until now the advice on how far to stand apart, how long was safe, were based on keeping below a certain viral load. But now you can develop covid from a smaller exposure to the virus.

They’ve also been very careful to not say ‘more infectious’ which would suggest that there’s a difference between transmissibility and infectiousness

They are using transmissibility because it is the correct scientific term. Something can be infectious, (ie a pathogen, something that causes disease) but not transmissible from one person to another person eg Lyme disease (spread by tick bites) or tetanus (from bacteria in the soil).

We know that the mutation in the new variant causes changes in the spike proteins. We also know that way that the virus infects people is by the spike protein attaching to the ACE receptors. It's also been observed that the new variant is more transmissible (from the increase in the number of people testing positive after being in contact with another person who has the new strain compared to the number of contacts infected by people who have other strains). Therefore, it is likely that the new variant is more transmissible because the changes in the spike protein make it better able to attach to ACE2 receptors.

I understood that it means the virus has mutated so that it can now latch on to its host easier. So the original virus had a harder time attaching itself to its host this mutated form has found an easier way. Something to do with spike and protein. One scientist on the bbc explained it really well for idiots like me the general public but I can't remember who it was now. Prof Calum Semple speaks regularly on the pandemic and I always find him easier to understand.

Surely if it's latching on better it's not just more transmissable but affecting the body more ?

From what I understand (science background but not in virology)

Is it airborne? Probably not; No evidence this is true; this would be enormous change.

Does it live longer on surfaces? Probably not; No evidence this is true. it's still an enveloped virus and they decay very rapidly outside of hosts.

Do droplets hold the virus for longer? Probably not; No evidence this is true; still enveloped; that won't ever change.

Or is it just more potent meaning that the viral load is higher and we are more likely to be infected? Maybe ... if "potent" means below.

More transmissible seems to mean the same exposure is more likely to establish itself as infection in you, because the virons are better at getting into your cells.

But still not wildly better at getting in, so you won't end up with a huge dose more than it was before. So the R-number has gone from maybe 2.9 before to 3.5ish. But the nature of exponential growth means it can accelerate that much faster...

Also, the new variant is seen hugely more in younger people than older people; so younger people (under 60s) are bigger % of total symptomatic cases.

@peridito

Surely if it's latching on better it's not just more transmissable but affecting the body more ?

Not necessarily because your individual immune system will still respond in the same way. I haven’t seen anything to suggest that it multiplies at a faster rate.

It’s still early days though and I did read one report that suggested high levels of virus had been found in blood samples compared to earlier samples. I don’t know enough about it though and whether they’ve compared samples from severely ill patients or a spectrum of mild to severe.

Oh dear cornetto thank you but I still can't figure it out .

So ...The body mounts the same defence and produces antibodies .

So .... We think that the virus latches on better - does that mean it attaches to a greater nos of cells or that it attaches to the same number but with greater ease ?

either way wouldn't that mean that the body's defence of antibodies needs to be stronger/greater than with the original strain ?

where am I going wrong ?

I read that link about blood samples. When I clicked on the article it was talking about swabs and not blood. It’s not thought to be a blood borne virus.

It’s not a more aggressive virus, as far as we know - so it just gets in easier. Your body will do what it would have done for strain one and there’s no suggestion that this mutation will make you sicker, it “just” gets in easier as it can bind itself better.

So if it was theoretically possible to say that giving someone a hug, for example; gave you an X% chance of catching strain 1 - strain 2 would have a higher percent, but you wouldn’t necessarily be sicker. You’d just be more likely to get it.

Or at least that’s my understanding, based on copious amounts of reading.

Thank you for asking this! I had puzzled over it & now (I think) I get it.

I think that the mechanism by which the new variant is more transmissible is understood.

However, what this means in terms of increased risk in a practical sense isn't yet fully understood.

I guess scientists can't simply look at the new variant and deduce things like the social distancing measures it requires, how long it lives on surfaces, or whether it generates a higher viral load.

I assume all these measures are discovered using data from people who have been infected- and this must be difficult to measure in a reliable way.

As an aside I'm mindful that 21 out of DH's 22 colleagues caught the virus and tested positive within four days of each other week commencing 14 December. No one attended work with symptoms, they all wore masks and visors, clean masks every two hours, deep cleans each evening and continual spot cleaning, no shared break times. Social distancing maintained. The work place is high value retail and no measure was spared to be as safe as possible.

DH runs the store and he's confident everyone followed procedures. We feel the issue was lack of ventilation. I also feel that in situations like this our health teams should be assessing what happened so they can learn from it.

Thank you HopeandDriftwood that does make it clearer .

Chaotic forgive me asking this ,I've been following your posts about your DH and his colleagues ,was there some suggestion that the restroom/WC might have been a weak link in the precautions ?

How is your DH doing ? And his colleagues?

Thank you so much.

My main takeout is that it 'latches on' better because of the spikey things. This at least helps me to to panic that it is suddenly airbourne or living on surfaces for much longer.

@peridito

Thank you HopeandDriftwood that does make it clearer .

Chaotic forgive me asking this ,I've been following your posts about your DH and his colleagues ,was there some suggestion that the restroom/WC might have been a weak link in the precautions ?

How is your DH doing ? And his colleagues?

@peridito hmm you're right yes, someone suggested an issue with shared toilets

They share 3 toilets. Their procedures were that each person cleans touch points after using the toilet, and they have a cleaning monitor whose job is to continuously clean meaning the toilets are cleaned three times a day. However I agree that's another weak point.

I do think though that they took more robust measures than most work places do, and so there is still something to be learned.

DH is much better thank you. DC and I didn't catch it (we were tested twice). This has confused me given how everyone caught it in the work place. He did isolate at hime after his test though.

Out of the 21, 3 of them have been really poorly. One in hospital (62, high BMI), two are under GP care on antibiotics and steroids (40s from BAME community).

Thanks Chaotic such a way to go before we can understand what's going on with this virus .

I'm glad to hear your DH is doing better but really sorry about the 3 who are seriously affected .Scary times

On the question of why some people catch it and others don't (or are asymptomatic), does anyone know of a person who was taking a vitamin D regularly, yet still had to be hospitalised? I'm talking about a dose which would have an impact, such as 3,000iu. Not the one a day vitamin that meets the NHS guidelines.
The answers would be anecdotal, but interesting.