Why has london had so few cases recently?

[yearinyearout]

What's going on here? The other day only 24 new cases, then 19, then none. I've read the news and it's not making sense to me, unless loads of people have had it and created some kind of herd immunity why is this so low?

From today's briefing-

The results of a government study suggest around 17% of people in London and 5% in the rest of the country have tested positive for coronavirus antibodies.

So the vast majority don't have antibodies.
83% of 9 million in London at risk, 95% of 58 million across the rest of the UK at risk.
Rather a lot of people.

Toffee - that’s a little bit sensationalist. Those under 45 have minimal risk from the virus, which badly affects mostly the over 60s and 70s.

I’d be very interested to see an age breakdown of the antibody test results. There have been previous reports that children and young people are much less likely to develop antibodies, which may suggest that they can fight the virus with their T cells rather than produce antibodies. If that is correct, the resistant population would be significantly greater and may help explain why London rates are so low, despite the population density, parks etc being packed

Me and my partner had it early March - he attended an event and sat next to someone who was later hospitalised with it

Loads of people who went to the event then were ill

The virus has run its course - as viruses do ! Until it mutates next season

Any idea what the sample size was for this test?

@Oliversmumsarmy

And January 2018 had many more deaths than both January 2019 and January 2020... January 2020 was not in any way special statistically compared to other Januarys. However, as the graph is posted shows, the number of excess deaths from March this year is massively, hugely, unmistakably higher than fluctuations in previous months and years.

It’s absurd to think that all those supposedly ill with Covid in January suppressed the curve by staying out of everyone’s way en masse at the same time without having infected anyone before they isolated!

You almost certainly “just” had the flu... As a previous poster said, six of her friends thought they had it earlier in the year - they all tested negative for antibodies.

I didnt see the briefing today. Did they say when those antibody tests were carried out? Because im sure they said it takes weeks to produce antibodies so if they were carried out a while ago it could be a higher percentage in the next round of tests

The more people who have immunity means the chances of it spreading is much less.

The figures for herd immunity aren’t that 100% of people have had it but nearer 70% have had it

If 70% of people are immune then that doesn’t mean that 30% are at risk. It means no one is at risk.

I think a lot more than 17% of people have had this virus in London.

Out of my friends only 2 haven’t had this illness or something very like it from December to today and one of them lives outside of London

Just wait for the post-VE Day celebrations spike to hit

What spike? Iwas there something special about that day that meant that no-one has shown symptoms for 2 weeks?

There has been huge increases in the availability of tests in the past 2 weeks, increases in who is eligible and new symptoms added to be eligible for a while test and yet still the numbers aren't going up.

Please come back liz and explain this. People seem to want there to be a spike purely to be able to say ”told you so”, there's nothing to suggest this unless VE day revellers are all giving testing a swerve out of embarrassment for their drunken stupidity. Possible but extremely unlikely.

Stating a fact sensationalist? I said they were at risk. Which is true. The level of risk will vary yes.

Given the very high levels of deprivation in London there are plenty of under 45s at increased risk. The ONS death figures noted the highest amount of deaths occurred in deprived areas. The top ten were London boroughs.

There's also a sizeable BAME community. They have above average rates of underlying conditions like diabetes and hypertension.

So I'd say it's vitally important that the government takes better measures to protect the many vulnerable Londoners this time round. Let's hope the reckless rush to get more back on the public transport - whilst the airports still have no restrictions (despite Sadiq Khan's pleas) doesn't lead to a bad second wave.

Might be news to you but the lives of people over 45 are as valuable as those younger.

Possibly even more shocking...those over 60 matter too..!
A revelation to some apparently.

Oh and before anybody trots out the 'But London's young' line. London has more elderly people than anywhere else in the UK.

It’s absurd to think that all those supposedly ill with Covid in January suppressed the curve by staying out of everyone’s way en masse at the same time without having infected anyone before they isolated!

Well said, if just everyone on MN who is sure they had it actually did we'd have had a noticeable increase in deaths since about November unless none of them came into contact with any vunerable people which as you say is absurd.

The results of a government study suggest around 17% of people in London and 5% in the rest of the country have tested positive for coronavirus antibodies.

Interesting - more than I had expected for London - but not enough to be close to herd immunity.

However, if say 1/4 of the population were “key workers”, of whom 50% had been infected, with the remaining of 3/4, just 7% had been infected, that would equate to help explain the sharp recent drop in infections.

What’s interesting about the whole herd immunity thing is that it isn’t straight forward we need x number of ppl to have sone level of immunity to stop transmission. The rapidly falling R rate in London could well be related to a ‘mere’ 17% with antibodies ... the ‘low hanging fruit’ effect where not all people are equally susceptible. There is some degree of community immunity at lower levels www.medrxiv.org/content/10.1101/2020.04.27.20081893v3

I think a lot more than 17% of people have had this virus in London.

A lot more than 17% may have had “flu-like symptoms” since November. However cold and flu didn’t suddenly disappear in 2020 to make a clear path for Covid.

Also, the 5% for the rest of the country will clearly vary massively. Perhaps 10%+ in Cumbria and 2% in Devon (just speculation over figures).

I didnt see the briefing today. Did they say when those antibody tests were carried out? Because im sure they said it takes weeks to produce antibodies so if they were carried out a while ago it could be a higher percentage in the next round of tests

Having looked into getting a kit for my partner, it seems it takes most people 2 weeks to produce enough antibodies to be detected, though they reckoned you should wait 3 weeks to be highly confident.

That’s true about antibodies so surely those percentages will increase in a few weeks?

Derbygerbil

This. It will also vary according to frequency of connections to London e.g. regular business or social. Particularly those with connections to Westminster - given they were reportedly rife with it.

surely those percentages will increase in a few weeks?

^ yes

I work in Westminster and live in north London.
@longestlurkerever
You’ve just outed yourself as being Keir Starner.

83% of 9 million in London at risk.

Actually, I would question this statement.

Based on data so far not everyone who gets exposed to C19 gets infected. The risk of transmission within a two-person household is less than 50%.

If you review the rate of infection at super spreading events, only 50% or fewer of the participants gets infected (the Washington choir example would be an exception but it was an older group exposed to a higher viral load):

www.erinbromage.com/post/the-risks-know-them-avoid-them

Based on my personal experience (which does not prove much but still provides a data point), I attended a large meeting in my office a couple of weeks prior to the lockdown. One of the attendees was later tested positive. Three of the meeting participants developed symptoms and got their diagnosis confirmed (via private testing). Everyone else including me never displayed any symptoms.

When we think about population level immunity, we should try to determine how many people have got natural resistance to the virus. The number will most likely be higher than 0%. If you add 17% of acquired immunity on top of that, the combination of the two may be making meaningful impact on R0 in London.

@wintertravel

You raise a very interesting point... The level of innate immunity, if indeed there is such a thing for Covid (I have read that there isn’t but so much of what I read turns out to be wrong!) is an extremely important variable.

I’ve tried to find the study you’ve referred to but failed... It would be very interesting to understand more about the household dynamics where spread did and did not occur. Some households pass like “ships in the night”... others are “in each other’s pockets”.

It seems that some people have spread Covid massively (c.100 people I believe in some cases - see South Korea nightclub recently!). If R is 2-3 in a non-socially distanced environment, this implies some infect far, far more than others, and potentially many (children for instance) aren’t very infectious at all, and potentially infect no one despite being in close proximity.

I wouldn’t surprise me if there were many mildly infectious people who were largely socially distant from others whilst infectious (didn’t travel on the tube, go to parties or spend an hour at the hairdressers) and who infected no one as a result.... but this is more than made up by those (possibly quite a small minority) who were naturally much more infectious and who frequented parties, had taxi rides etc. It’s quite plausible that 10% of those infected are responsible for 90% of the infections.

This would also help explain why it could have been present for weeks in Europe before it started to grow rapidly - it may even be that the median R0 is zero!

That’s true about antibodies so surely those percentages will increase in a few weeks?

If numbers of infections are much lower now, any rise will be tiny in comparison.

@wintertravel1980 have you seen the report from the Diamond Princess? About 30% of people on the ship didn't catch the virus at all, displaying a natural non susceptibility.

About 30% of people on the ship didn't catch the virus at all, displaying a natural non susceptibility.

That’s one possible conclusion. Alternatively it could be that they weren’t in close enough contact with a sufficiently infectious infected person to have caught in the time between it arriving on the ship and being confined to cabins.