Science, Research & Technology Capability and Influence in Global Disease Outbreaks (#COVID19) @CommonsSTC
Summary THREAD
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Summary THREAD
👇
Prof Mark Woolhouse is the first witness (epidemiologist):
Harms will be done by lockdown, healthcare provision, mental health, social wellbeing, education, & economy
Balanced assessment needs both sides to be modelled, only one side of the equation was quantified by modelling
Harms will be done by lockdown, healthcare provision, mental health, social wellbeing, education, & economy
Balanced assessment needs both sides to be modelled, only one side of the equation was quantified by modelling
Q: Have we been too reliant on predictions?
Lessons to be learnt on communicating outputs of modelling, need to give a range of scenarios, single prediction not helpful
Lessons to be learnt on communicating outputs of modelling, need to give a range of scenarios, single prediction not helpful
Q: Focus on hospitals cost lives?
Woolhouse: we can’t do full reckoning of lockdown impact now, but will be lost livelihoods, wellbeing, & lives
Seen in Ebola, indirect effects were *considerably worse*
“I fear cost of lockdown will be considerably worse than the disease”
Woolhouse: we can’t do full reckoning of lockdown impact now, but will be lost livelihoods, wellbeing, & lives
Seen in Ebola, indirect effects were *considerably worse*
“I fear cost of lockdown will be considerably worse than the disease”
Witness now is Prof Johan Giesecke, Former State Epidemiologist for Sweden:
Undiagnosed cases are far higher than estimated, and infection fatality rate has been vastly overestimated. Fatality rates for new diseases are almost always over estimated.
Undiagnosed cases are far higher than estimated, and infection fatality rate has been vastly overestimated. Fatality rates for new diseases are almost always over estimated.
Prof Woolhouse: Wuhan data wasn’t clear in the very significant effect of age on fatality rate. But burden of disease is vastly concentrated in elderly, 80% of UK deaths in the 20% oldest. Should have influenced public health response.
Q about immunity and susceptible:
Woolhouse: longer term, herd immunity will be important. But they didn’t impact first wave policy
Woolhouse: models should now be based on data (not predictions)
Giesecke: (agrees)
Woolhouse: longer term, herd immunity will be important. But they didn’t impact first wave policy
Woolhouse: models should now be based on data (not predictions)
Giesecke: (agrees)
Q: Imperial model which influenced lockdown was based on influenza, what effect does this have?
Giesecke: flu spread by children, not true of COVID, this is a big difference. It’s not community spread that’s homogenous, but more clusters...
Giesecke: flu spread by children, not true of COVID, this is a big difference. It’s not community spread that’s homogenous, but more clusters...
...Woolhouse: I would add that from a UK perspective the flu models were based on reasonable worst case, but apparent early on that this did not match reasonable worst case for COVID 19, there was a lag whilst this was adjusted.
Q: 3 models supported lockdown, did you agree?
Woolhouse: "we couldn’t think of anything better to do given the information we had at the time, so I supported lockdown, but I was very much hoping it would be a shorter measure, & that we would move to more focused response"
Woolhouse: "we couldn’t think of anything better to do given the information we had at the time, so I supported lockdown, but I was very much hoping it would be a shorter measure, & that we would move to more focused response"
Woolhouse: (on predicting human behaviour) not possible, and must consider spontaneous and enforced behaviour change. Models in March were strong on human behaviour. But this went “out of the window” when lockdown happened.
Giesecke: “(Sweden) we are sometimes blamed or called names because we don’t have a hard lockdown, in mid March when the government said we have some restrictions... we won’t influence them by law… but diminish your social contact... contact intensity in Sweden went down by 70%”
Woolhouse: focus on R number unhelpful. Public need stats that help them identify their own risk. We have not succeeded in communicating where the risks lie, risks or vastly in elderly in frail.
Prof Mark Woolhouse:
"Epidemic curve for Sweden is indistinguishable from that of Scotland” @NicolaSturgeon
"Epidemic curve for Sweden is indistinguishable from that of Scotland” @NicolaSturgeon
Woolhouse: “A few weeks ago R was below 1 in the community, but above 1 in care homes“
“The last place we want this infection spreading like wildfire is in care homes”
[R] “detracts focus from what really matters”
“The last place we want this infection spreading like wildfire is in care homes”
[R] “detracts focus from what really matters”
Q: Granularity of modelling does not match over-granularity of rules currently in place.
Giesecke: growing awareness that COVID is clustered, not as commonly spread in population as flu, we should put more emphasis on where spread actually takes place: testing & contact tracing
Giesecke: growing awareness that COVID is clustered, not as commonly spread in population as flu, we should put more emphasis on where spread actually takes place: testing & contact tracing
New witnesses for second half:
Prof Neil Ferguson, Imperial, & Prof Matt Keeling, Warwick, & Dr Nicholas Davis, LSHTM
Prof Neil Ferguson, Imperial, & Prof Matt Keeling, Warwick, & Dr Nicholas Davis, LSHTM
Q: Deaths were originally estimated to not exceed 20K?
Ferguson: Heavier seeding of virus in early March from Italy and Spain (primarily), around 1500-2000 cases imported. We hadn’t seen until that point. More than expected...
Ferguson: Heavier seeding of virus in early March from Italy and Spain (primarily), around 1500-2000 cases imported. We hadn’t seen until that point. More than expected...
...[we] underestimated how far into the epidemic UK was. We assumed care homes would be shielded, what we’ve actually seen are infection rates 4x higher than the general population in care homes
Our death toll would probably be half what it is now had we have [known? inaudible]
Our death toll would probably be half what it is now had we have [known? inaudible]
Q about modelling effect on #carehomes
@neil_ferguson: didn’t have enough data to understand the transmission in care homes,we also had the rather optimistic assumption that somehow, which was policy that elderly and vulnerable would be shielded, and that simply failed to happen
@neil_ferguson: didn’t have enough data to understand the transmission in care homes,we also had the rather optimistic assumption that somehow, which was policy that elderly and vulnerable would be shielded, and that simply failed to happen
Ferguson: we didn't anticipate that it's very common for [care home] staff to work in more than one facility, and that accelerated the spread of the infection from one care home to another.
We were not anticipating the epidemic to be close to the size it has been in care homes
We were not anticipating the epidemic to be close to the size it has been in care homes
Ferguson: "lockdown a week earlier would have reduced the final death rate by at least a half. Whilst I think the measures given what we knew about the virus then were warranted, certainly had we introduced them earlier we would have seen many fewer deaths"
Ferguson:"Focus on where transmission is happening is critical for coming out of lockdown. We want to be in a position where we can identify clusters of infections rapidly&impose locally targeted interventions which are not as economically disruptive as overall lockdown measures"
Prof Keeling: we're not going to see a uniform spread across the country, it;s going to be in pockets.
Dr Davies: better knowledge of location of infection is important going forward
Dr Davies: better knowledge of location of infection is important going forward
Q: When NHS England sent people back to #carehomes from hospitals, was SAGE not concerned?
Ferguson: I don't remember it being discussed in SAGE. I only became aware of it later.
Ferguson: I don't remember it being discussed in SAGE. I only became aware of it later.
Q: academic work suggests lockdowns have not influenced virus curves:
Ferguson: huge spikes in all cause mortality across many countries [no response about lockdown here]
Ferguson: huge spikes in all cause mortality across many countries [no response about lockdown here]
Prof Keeling disagrees that models were based on flu, says model was designed specifically for COVID. Couldn't get data about care homes to include in the model.
[in March] "we didn't even know how many people were in care homes"
[in March] "we didn't even know how many people were in care homes"
Q: models' interactions between people based on survey data. How does that feed into the models?
Prof Keeling: can't model very granular things e.g. going for a haircut. Longer, closer interactions are higher risk, but after that much of what we do is just matching to avail data
Prof Keeling: can't model very granular things e.g. going for a haircut. Longer, closer interactions are higher risk, but after that much of what we do is just matching to avail data
Ferguson: if we want to maintain control of transmission, there are only a certain number of [social] contacts that can be permitted, and then it is a policy makers decision, if they want to keep R below one, of which types of contact to prioritise
Keeling: getting R just below 1 is not enough, needs to be as low as possible. Minimising interactions as much as possible to minimise risk
Q to Ferguson: your model puts human activity into v broad categories; home, school, work, and then other. Could we have been more sophisticated in this? Could have helped care homes situations?
Ferguson: we are doing this
Questioner: now?
Ferguson: now.
Questioner. Yeah.
Ferguson: we are doing this
Questioner: now?
Ferguson: now.
Questioner. Yeah.
Q: there was early evidence from US that virus getting into care homes would have devastating effects: I'm surprised there wasn't more effort put into getting this info.
Keeling: "Hindsight is a great thing. We were all focused on outbreak doubling every 3days, concerned about..
Keeling: "Hindsight is a great thing. We were all focused on outbreak doubling every 3days, concerned about..
...losing control in the NHS, about ICU becoming full, and I think there was only so much of us and only so much time, and, we were all focused on one area and probably we y'know it was mentioned we thought about it sort of oh yeah care homes are important and we thought...
...they were being shielded, and we probably thought that was enough and maybe we should have been, jumping up and down saying 'had anyone checked care homes'?"
Ferguson: what clarified need for lockdown was not modelling but that this was an epidemic that we thought at the time was doubling every 4days, and 0.5-1.5% of people infected would die, and it was [inaudible] up of those numbers &the fact that the NHS wouldn't be able to cope..
...that really, instigated that decision.
Q: did you think given severity, and disease spreading more quickly than expected, were you disappointed that it took 9 days to make that decision?
Q: did you think given severity, and disease spreading more quickly than expected, were you disappointed that it took 9 days to make that decision?
Ferguson: "I said earlier that in retrospect I would have much preferred to have been taken a week earlier given that many lives would have been saved"
Ferguson: we had always hoped that we would be able to replace lockdown with more targeted measures, after you get past the first wave of transmission, but until we have a vaccine, yes, we will have to permanently be putting out fires with this virus and stopping large epidemics
Q: probably the best policy for the UK was halfway between what we did and the Swedish model?
Keeling: bit of an awkward question... you're asking us to balance multiple aspects here, we're all epidemiological modellers with experience in public health, and hat I think you're...
Keeling: bit of an awkward question... you're asking us to balance multiple aspects here, we're all epidemiological modellers with experience in public health, and hat I think you're...
...asking for is a balance between public health measures and also the economy and social welfare, and I don't think that's ever been made clear by anybody as how we actually try and balance those multiple elements together
Ferguson: report 9 models were short of what was actually implemented, lockdown was more draconian, we actually assumed more people would still be going to work for instance, with some social distancing...
Q about direct and indirect deaths:
Ferguson: SPI-M investigating this now. Only now we're getting the data to allow us to quantify those contributions to deaths...
Ferguson: SPI-M investigating this now. Only now we're getting the data to allow us to quantify those contributions to deaths...
[Ferguson continued]:
..."it'll be several months before we see the potential negative consequences of restricted access to healthcare, excess cancer deaths will happen later, they haven't happened yet"
@ProfKarolSikora
..."it'll be several months before we see the potential negative consequences of restricted access to healthcare, excess cancer deaths will happen later, they haven't happened yet"
@ProfKarolSikora
Q about assumption that people's behaviour will return to pre-pandemic levels after lockdown
Keeling: people will perhaps make up for lost time and go and visit people they haven't seen, so we try to fit a halfway house making that assumption. Our work does look at more options
Keeling: people will perhaps make up for lost time and go and visit people they haven't seen, so we try to fit a halfway house making that assumption. Our work does look at more options
Keeling: R only just below one so it wouldn't take much of a return to normal for R to go above 1 and there be a second wave
(my own thoughts for a change: this makes a lot of assumptions about population susceptibility)
(my own thoughts for a change: this makes a lot of assumptions about population susceptibility)
Q about length of immunity:
Ferguson: reinforces going with lockdown, compared with mitigation, or herd immunity strategy and shield the elderly, relies on people being immune at the end. We think 8% of population have had coronavirus.
Ferguson: reinforces going with lockdown, compared with mitigation, or herd immunity strategy and shield the elderly, relies on people being immune at the end. We think 8% of population have had coronavirus.
Keeling: if immunity only ~6 months, vaccine only way to fully release lockdown and go back to normal.
Q: all models assume whole population is susceptible, but some research suggests exposure to other coronaviruses gives some immunity?
Ferguson: we allow for some variation in susceptibility, particularly in children, and variation in exposure.
Ferguson: we allow for some variation in susceptibility, particularly in children, and variation in exposure.
Ferguson continued: hypothesis around cross-immunity is interesting, argued to be mediated by T cells, immunologists tell me that's more likely to reduce risk of severe disease rather than whether someone will get infected, but may not transmit onward.
Ferguson continued: People with lower or no symptoms transmit less.
Q about superspreaders:
Keeling: aggregate view of UK, scaling up to entire population, superspreader effects get 'smeared out'
Keeling: aggregate view of UK, scaling up to entire population, superspreader effects get 'smeared out'
Davies: LSHTM models take account of superspreading.
Q: have limitations of models been communicated to the public?
Ferguson: I thin they have to policy makers, it's a challenge in terms of time, we do what we can in terms f public communication, more certainly could be done
Ferguson: I thin they have to policy makers, it's a challenge in terms of time, we do what we can in terms f public communication, more certainly could be done
Davies: models aren't perfect predictions of reality, they are a tool, I don't know whether that's been adequately communicated to the public.
Keeling: they're forecasts, the longer you go on the more uncertainty there'll be.
Keeling: they're forecasts, the longer you go on the more uncertainty there'll be.
Ferguson: test and trace mapping where transmission occurs is important for future steps.
Q related to an epidemiologist [not named] saying more views should be represented on SAGE?
Ferguson: SAGE evolved over time and is more diverse now, advice comes from a wide range of other sources too
Ferguson: SAGE evolved over time and is more diverse now, advice comes from a wide range of other sources too
Q Keeling said R rate should be as low as possible, lockdown permanently?
Keeling: we want fastest decline in cases we can, to get out of this, we can start lifting lockdown.
Keeling: we want fastest decline in cases we can, to get out of this, we can start lifting lockdown.
Ferguson:
"very rigorous and well established and sophisticated policy advice structure which exists within UK government in crises, may have led to a certain degree of caution in decision making, in balancing evidence, certainty and uncertainty, being very aware of costs...
"very rigorous and well established and sophisticated policy advice structure which exists within UK government in crises, may have led to a certain degree of caution in decision making, in balancing evidence, certainty and uncertainty, being very aware of costs...
...risks of second wave in which frankly I think in other countries policy makers weren't aware when they made decisions they made there almost certainly are lessons to learn in that"
END.
2.5 hours later...
You can see the whole video here, if you're so inclined: parliamentlive.tv/Event/Index/b2…
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2.5 hours later...
You can see the whole video here, if you're so inclined: parliamentlive.tv/Event/Index/b2…
✌️ Please share my work by retweeting first tweet in this thread, TY!
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