I know people will accuse me of 'fearmongering', but I'm really concerned by the potential threat posed by Nu: Why? TL;DR
-The rapid growth to dominance/near dominance in multiple parts of SA
-growth accompanied by increase in R
-accumulation of mutations - many of concern
Yesterday, we heard about the detailed work done on surveillance and characterisation of this new variant from SA. It has far more mutations compared to the original variant compared to delta. Many of these are shared with other VOCs, while many are new:
Many of the mutations are associated with escape at least in laboratory studies (although we don't have data on this particular variant with all its mutations yet). But early data suggests mutations associated with higher transmissibility & escape.
From an epidemiological perspective the aspects that are most worrying are:
1. Rapid increase in frequency of this variant in Gauteng & other SA provinces against a delta background. While the sequencing data will be skewed (left), data from PCR testing shows rapid growth (right)
As this variant (like alpha) is detectable on PCR tests (it shows spike dropout- also called SGTF), we can look at changes in frequency across multiple provinces. It shows consistent rapid rises to dominance or near-dominance across all regions, although samples are small in some
Worth remembering that delta took 6 weeks or more to gain dominance in most regions. Here we're seeing a variant that's likely been detected early (given the signature on PCR tests) that's rapidly gone from 0% to 40-60% in a matter of weeks (2 wks or so). That is very worrying.
2. The rise in frequency is associated with an increase in R- this is something we saw with both alpha and delta, and once again suggests that it increases transmission, either through increased transmissibility, escape, or more likely both.
Gauteng current has an R of about 1.9, with the Nu variant being dominant, which again suggests a high effective R for this variant, and a considerable advantage over delta.
While this advantage might be different in different contexts (background transmission, background immunity), it does suggest a very high level of fitness relative to delta (escape/transmissibility/both) in the SA context currently.
For a variant to become dominant so quickly, we might expect a growth advantage of 2x or more against delta. Of course this isn't definitive in any sense, given we need to look at this in different contexts, but it is very concerning, even as we wait for more data.
Worryingly, it's spread quite rapidly across SA, which suggests that it's very likely spread to many other countries as well. We've already identified cases in Israel, Belgium, Malawi, and the extent of spread will be greater than we know.
Although there is much uncertainty, given the potential threat, it makes sense to assume a worst case scenario and plan for this, rather than respond too late. If the response turns out to be an overreaction, it can always be scaled back.
But missing early opportunities to contain a real threat will be fatal. As with delta. This means strict border restrictions- not just prospective red list bans, but more comprehensive mandatory quarantines across the board (given this is likely widespread).
PCR testing with TaqPath assays that are able to detect these variants in travellers and those quarantining, as well as retrospective identification across people who have travelled in from affected areas recently.
The holes in UK response concern me👇
Israel is already taking many of these measures, and other countries should follow:
Given it's very likely this variant may already be in the UK, given rapidity of spread, we also need to consider domestic measures to contain this, as Israel is doing. This variant is likely to outpace surveillance efforts given the sort of spread seen so far.
This means we can't rely solely on TTIS to contain it. We need to take measures like mask mandates (high grade-masks), and strict mitigations in classrooms, where spread of alpha and delta initially happened, and Nu will also likely happen if it does enter the community.
It also means speeding up vaccination efforts- boosting and vaccinating children - while the variant may show a degree of escape, every single layer is needed, and will help. Israel is putting HEPA filters in classrooms- we should speed this up in the UK as well.
Border restrictions are vitally important, even if the variant is present here already, because this can slow spread, which may give us vital time to prepare a response to protect the public and NHS maximally - particularly at a point the NHS is already in crisis.
Before I get accused of more fearmongering, I don't know if the variant will have all the properties above, but the signs aren't good, and so far it looks like a possible step change from delta. I hope I'm wrong about this, and that future research shows otherwise.
But it's best to plan for the worst, rather than get by on hope. Much better to overreact than underreact given the potential of this threat.

And signs so far suggest that the potential threat is high.
Just want to add this thread, as this seems to suggest the growth advantage relative to delta may be much higher than my earlier tweet suggests (5-6x higher than delta). We don't know yet, but either way, it's very worrying.

Worth remembering that this growth rate doesn't really tell us about Ro or transmissibility, because both escape and transmissibility confer an advantage, and we still don't know who is susceptible to Nu, and the level of cross-protection from delta and other variants.

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More from @dgurdasani1

27 Nov
Today's briefing appears to be an exercise in doing the bare minimum while seeming to signal that our response is in someway proportionate to the potential threat. Let's be clear- this response doesn't even go far enough to deal with delta, far from dealing with anything beyond🧵
Let's remember we're entering a period of uncertainty and high *potential* threat with our NHS already under unsustainable pressure (something that doesn't seem to have been discussed at all during the briefing)! Ambulances are on black alert with emergency services struggling.
We've been having excess deaths and very high transmission for months, and are currently at 50K cases or so a day, and rising, esp in children. This has been accompanied by huge rises in self-reported long COVID in young people- something not addressed at all in the briefing.
Read 20 tweets
27 Nov
For 19 months, I've been constantly attacked for advocating for elimination, and saying SARS-CoV-2 isn't a virus we can and should live with. It's been evolving in one direction from the start- greater transmissibility, escape & virulence. 🧵
But the hopium on 'benign endemicity' has been widespread- the idea that it'll magically become the common cold when all evidence has been pointing the other way for 19 months. Unfortunately, early signs don't look good. Image
So, I'll say this again. And trolls and my 'colleagues' can and will attack - but progressive coordinated and supported global elimination was the only way to really deal with this threat. And with every new variant, it gets harder to do this.
Read 10 tweets
27 Nov
61 people on a flight of 600to the Netherlands tested positive for COVID-19 on screening flights from SA - variant status now being assessed. Not imposing mandatory quarantine from all regions including SA is a huge failure of UK policy. This variant is very likely widespread.
Even if it's here (which I think it likely is), we need to slow spread- and we seem to be doing nothing in the face of what is a fast changing situation. Why? This is precious time for acting, and planning next steps, to protect the public in an evolving situation.
We need comprehensive mandatory border quarantines from all regions, mask mandates (high-grade masks), mitigations in schools (masks, ventilation, bubbles, quarantine for contacts), caps on large gatherings, and speed up of boosters, vaccines to kids.
Read 5 tweets
25 Nov
The document that's being shared in this picture by @ALewerMBE is by @DrJBhattacharya an architect of the Great Barrington Declaration that advocated for 'herd immunity by infection'. Jay was disallowed as an expert witness in court due to misrepresentation of evidence on masks!!
Major flaws were highlighted in his testimony by multiple judges, with one concluding that he wasn't qualified to be an expert witness, and others suggesting his testimony was problematic. This is the person whose advice our govt ministers are sharing?
Read 4 tweets
24 Nov
Will the tsunami of misinformation coming from the Telegraph ever stop? No, depression is not 'ordinary unhappiness', & stigmatising prescribing or taking anti-depressants isn't helpful. I've been on ADs for 9 yrs & my only regret in is not taking them sooner. 🧵
I, for years, despite being a medic, and having prescribed ADs to patients and seeing them getting loads better didn't take them myself, because I felt I should be able to control it somehow and get myself better. I lost entire decades of my life to it.
I shouldn't have. I did psychotherapy as well, which was incredibly useful, but ADs alongside made a huge difference to my life. Please don't suggest depression is just normal sadness due to 'life'. It isn't. It's hard to imagine depression if you haven't experienced it.
Read 8 tweets
24 Nov
It's not a choice between vaccines & mitigations - lockdowns represent a failure to control transmission pre-emptively. What's needed is a multilayered approach of vaccines + boosters + mitigations (high-grade masks, school mitigations, ventilation, test, trace, isolate)
We must separate out lockdowns & mitigations. Lockdowns are only needed again and again if we don't have robust mitigations in place. Many of these don't require a huge sacrifice, but are highly effective (masks indoors, ventilation). There needs to be strong messaging about this
It's not right to say 'restrictions' will be needed for a long time because it will prevent build up of population immunity by infection. Immunity by infection is not desirable- because it's by infection! - which we're trying to prevent! Vaccines do this safely & effectively.
Read 11 tweets

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