Case numbers dropping due to lockdown

[womanity]

Not vaccine.

Why has Boris said this? I don’t understand.

I get he wants people to still follow rules, but he also wants them to get vaccinated, right?

Can someone explain the assertion up thread that vaccines don’t work when case numbers are high?

If we had not locked down, there would have been a load more cases, seriously bad situation in hospitals and tens of thousands more deaths, no question. But if we had rolled the vaccine out at the same rate, why would it not work? We would arguably get to herd immunity sooner, because as well as all the people immune through vaccination there would be more people immune through infection.

@Cornettoninja not London, no. Central Scotland. I'm 1st dose vaccinated but it's the variants I'm worried about.

@PuzzledObserver I believe they mean the vaccine reduces R by maybe 1/3rd, but that makes very little difference to the ability for track and trace and other light touch measures to prevent spread if the volume of infections is high. Whereas the same reduction when the volume of infections is low means that those light touch measures can reduce R.

ie imagine the reasonable hypothesis that track & trace can half R as long as it's only needing to track trace at most 50 people in a particular area at a time, if it tries to track 500 it only reduces R by a small amount.

Oh and reaching herd immunity through infection has never been considered, all infection is considered bad.

@sirfredfredgeorge

Oh and reaching herd immunity through infection has never been considered, all infection is considered bad.

I understand it’s not desirable. It surely makes sense though that people who have been infected will make a contribution to reducing the spread among those who remain susceptible, in the same way that those who are vaccinated do, no?

@PuzzledObserver

Can someone explain the assertion up thread that vaccines don’t work when case numbers are high?

If we had not locked down, there would have been a load more cases, seriously bad situation in hospitals and tens of thousands more deaths, no question. But if we had rolled the vaccine out at the same rate, why would it not work? We would arguably get to herd immunity sooner, because as well as all the people immune through vaccination there would be more people immune through infection.

What do you mean by "if we had rolled the vaccine out at the same rate"?

@PuzzledObserver I cant find the article I read but vaccines work better with lower community spread.

In my head I kind of see it as a fire - vaccines are a good way of suppressing small fires by breaking the chain of transmission (which they do seem to) but struggle put out a huge out of control wildfire - we had a wildfire.

Its not that they dont work - its just it is quicker to do it with lower spread.

At least that is how I see it!

Isn't one reason that the vaccine won't work properly if it's given to someone with an active infection? Vaccines are meant to prevent rather than cure. So preffective if there's high rates of infection (including many asymptomatic) the vaccine rollout won't be very effective.

*presumably

I said on a different thread, lockdown gets cases down and vaccines keep them down when we open things up again
Good summary here.

@PrincessNutNuts What do you mean by "if we had rolled the vaccine out at the same rate"?

I mean if we had vaccinated the exact same number of people at the same time, but without a lockdown being in force.

I suppose I'm thinking of the difference between introducing a vaccine for what is still a novel disease with many people unexposed, compared to one which is endemic, e.g. measles. When routine measles vaccination started, it took several years before the numbers fell from hundreds of thousands (plus tens of deaths) to a few thousand (with no deaths). But it happened eventually.

Ergo I assumed that if we vaccinate enough people against Covid we would eventually suppress it to very low levels, even without lockdown. We'll do it quicker with lockdown, and therefore save lives, that's the difference (I think).

[quote PuzzledObserver]**@PrincessNutNuts* What do you mean by "if we had rolled the vaccine out at the same rate"?*

I mean if we had vaccinated the exact same number of people at the same time, but without a lockdown being in force.

I suppose I'm thinking of the difference between introducing a vaccine for what is still a novel disease with many people unexposed, compared to one which is endemic, e.g. measles. When routine measles vaccination started, it took several years before the numbers fell from hundreds of thousands (plus tens of deaths) to a few thousand (with no deaths). But it happened eventually.

Ergo I assumed that if we vaccinate enough people against Covid we would eventually suppress it to very low levels, even without lockdown. We'll do it quicker with lockdown, and therefore save lives, that's the difference (I think).[/quote]
Ok I see.

Vaccines versus the virus is a numbers game.

Vaccines work.

These vaccines work very well.

But if there's more people with the virus circulating than there are people with vaccine-led immunity then the virus will continue to infect people, hospitalise them and kill them at a much faster rate than we have vaccinated.

We started vaccinating in December and all numbers continued to rise alarmingly. Without lockdown a month later they might still be rising now or (possibly more likely) have plateaued at a much higher Brazil-esque level than we had ever seen before.

This wouldn't have meant that the vaccines don't "work." Just that we have allowed too many cases before we had enough people vaccinated.

So whilst the vaccines did their job and broke some chains of transmission and stopped some of the vaccinated from being hospitalised or dying, a few vaccinated people are no match numbers-wise for a lot of infected people. The virus can jump from in-vaccinated person to in-vaccinated person and like a lone store security guard on Black Friday the odd vaccinated person in the group doesn't have much impact.

God that's long - sorry.

But there's more.

If we had tried to do it without lockdown we would be just begging for more variants to emerge and render the vaccines less and less effective, leading to more deaths amongst the vaccinated and actively hampering our efforts to get to herd immunity - the game changing point where the vaccines are effective at a society wide level.

@LolaSmiles

I said on a different thread, lockdown gets cases down and vaccines keep them down when we open things up again Good summary here.

Well that's the hope but it's a numbers game, and we are opening up before the population is vaccinated.

At the moment, in a gym, or a school or a street of outdoor beer patios in Soho if the virus is present it is still quite unlikely to be blocked from spreading by everyone having been vaccinated.

Covid can easily spread from person to person through the crowd, who then helpfully take it to other locations such as work, home and public transport and spread it there too. (Because those are also locations where most people are unlikely to be fully vaccinated yet)

If covid is present and there are not enough vaccinated people then the virus can happily jump from sheep to sheep without getting blocked by meeting mostly vaccinated sheep.

[quote Quartz2208]@PuzzledObserver I cant find the article I read but vaccines work better with lower community spread.

In my head I kind of see it as a fire - vaccines are a good way of suppressing small fires by breaking the chain of transmission (which they do seem to) but struggle put out a huge out of control wildfire - we had a wildfire.

Its not that they dont work - its just it is quicker to do it with lower spread.

At least that is how I see it![/quote]
I can get behind vaccinated people being like fire doors.

If the fire (covid) keeps coming up against fire doors (vaccinated people) in every direction then it can't spread far.

If it only meets the occasional fire door then that lone fire door can't do much to stop it. It just spreads in directions where there isn't a fire door to stop it.

@PrincessNutNuts

God that's long - sorry.

But there's more.

If we had tried to do it without lockdown we would be just begging for more variants to emerge and render the vaccines less and less effective, leading to more deaths amongst the vaccinated and actively hampering our efforts to get to herd immunity - the game changing point where the vaccines are effective at a society wide level.

I have limited knowledge of viruses, immunology etc and am thoroughly confused about this issue of variants. PrincessNutNuts are you saying that a variant may emerge that will overcome the vaccines ie render the vaccines we have ineffective? Are there any examples of this having happened? Are the vaccines we have effective against all the variants out there right now? I have tried reading up on this and there just seems to be a lot of white noise and no definitive answers. I have read some scientists say we don't have to worry about variants as the vaccines we have developed will be able to handle them. If that is the case - and I have no idea if it is or not btw - why is there such a big fanfare about variants?

@PuzzledObserver

I understand it’s not desirable. It surely makes sense though that people who have been infected will make a contribution to reducing the spread among those who remain susceptible, in the same way that those who are vaccinated do, no?

They do.

But because they are relatively small in number it's a relatively small contribution.

It might shut off one avenue of spread but until the herd immunity threshold is reached there will be countless others.

They might not catch it from the drunk guy shouting an anecdote over the crowd noise on the crowded beer patio and they might not take it with them to home and work - but everyone else is close proximity to that guy will.

Once people are mingling in any sort of numbers the fact that there is a previously infected person present does jack shit to be colloquial. (Same for a single vaccinated person.)

What's needed is for most people present to have a high level of immunity through vaccination - and potentially waning natural immunity to old variants earlier in the pandemic is the squirty cream on top of that.

@savethegrannies

Many of the currently known variants of concern have some degree of ability to get round antibodies from infection or vaccines. So they can already make the vaccines less effective, not completely ineffective.

(The Daily Mail chart is about 3 weeks old but it gives a good clear overview.)

Whatever variant is most successful at spreading will become dominant.

Restrictions and lockdown have held the Brazilian, the South African and all the other variants back.

Opening up gives them chance to spread and opportunities for successful mutations to emerge.

Sooner or later one that renders the vaccines a lot less useful will emerge.

@PuzzledObserver, imagine community transmission is really high - say that if no-one was vaccinated, each person with covid would infect four others on average. Then you vaccinate 50% of the population. If you start off with 40 infected people they could potentially transmit it to 160 others, but half will be vaccinated, so they only transmit it to 80. Those 80 have 320 potential contacts, but again half are vaccinated so the actual number of new infections is 160, and so on. You still have exponential growth, it's just slower than it would be without the vaccine.

On the other hand, imagine community transmission is low and each person only has 1.5 potential contacts on average. You start with 40 infected people again. Without the vaccination program they would infect 60 others, but with half the population vaccinated the actual number is 30. Those 30 would normally infect 45, but because of the vaccine they only infect 22 or 23. The number of new cases drops each time, and after a few rounds of infections the virus will be eradicated. As the percentage of vaccinated people increases, the number of average contacts that's required to sustain exponential growth also goes up, so eventually herd immunity kicks in and the number of cases will fall even if we go back to mixing freely.

Not an expert or anything, but that's how I made sense of it to myself!

PS - you're right that even in the high transmission scenario we would still eventually suppress it with the vaccine once the proportion of people vaccinated was high enough (assuming no resistant mutations etc), but it would take longer, and in the meantime there'd likely be a massive surge in cases amongst the unvaccinated population.

The vaccine doesn't stop transmission I'm some cases it simply hopefully prevents the need for hospitalisation/deaths

Each vaccinated person NOT hospitalised (or hospitalised for non covid but not
now havingg a high viral load ) reduces the spread in the hospitals.

I think the problem is that Boris explained himself very badly, as usual. Dreadful messaging, and no context or attempt at explanation. I don't know what the fuck he was thinking putting it as he did - maybe he doesn't either. Many people will have read or heard that and wondered why they should bother with the jab, esp in light of the issues in the press with AZ. Very poor comms, as usual.

@picklewick

The vaccine doesn't stop transmission I'm some cases it simply hopefully prevents the need for hospitalisation/deaths

www.medrxiv.org/content/10.1101/2021.04.08.21255108v1 - actually it's looking increasingly likely it makes a huge difference in preventing transmission. This is a preprint, but as more are vaccinated and time goes on there's no reason not to be incredibly positive about this. www.medrxiv.org/content/10.1101/2021.04.08.21255108v1

PrincessNutNuts
Many of the currently known variants of concern have some degree of ability to get round antibodies from infection or vaccines. So they can already make the vaccines less effective, not completely ineffective.
QUESTION - With respect, this seems a bit vague. When you say less effective, do you mean people will get ill still? Get ill but not die? How ill? Hospitalised ill? Are there any stats/evidence of this yet?
(The Daily Mail chart is about 3 weeks old but it gives a good clear overview.)
Restrictions and lockdown have held the Brazilian, the South African and all the other variants back.
QUESTION - Is there any proof of this? Or is this anecdotal?
Sooner or later one that renders the vaccines a lot less useful will emerge.
QUESTIONS - Are you certain of this? Is there any precedent here? Also, when you say a lot less useful what do you mean? Again, do you mean it would mean the vaccine was rendered completely ineffective? Or that the person got ill but did not die?