Thread by @AppgCoronavirus

🗣Dr.Claire Steves continued:
“Looking in the national core studies, from cohort studies across the UK we’ve looked at 10 different longitudinal studies. Our best estimates are that about 5% of middle aged people are experiencing long term.. 27/
#APPGCoronavirus #LongCovid

“..symptoms that are lasting about 12 weeks that are affecting their ability to function as normal. It’s less in younger populations, about 1.2% of 20 year olds. Overall that leads to approximately about 3% of the population that have had coronavirus, have had symptoms.. 28/

“..that affect their life for more than 12 months. I think personally that’s probably about where I’d sit the best estimate. But these things are difficult to really determine. So here’s our projection, while I’m saying it may be slightly less than what ONS said.. 29/

“..what’s happened since their data was collected was of course the Omicron surge. So we, in ZOE have been producing this estimate of the number of cases everyday that is being produced as it were by the pandemic curve. Because we’ve seen in our previous data, that there is.. 30/

“..a very close correlation between the incidents of Covid and then subsequent development of Long Covid symptoms within the app. Using that best estimate of 5% in the higher age group and 1.2 in the lower age group we’ve computed this and you can see the real spike.. 31/

“..that we’ve just seen in Omicron, that because the numbers of people affected by Omicron was so high, that assuming Omicron has the same rate as Long Covid, which we don’t know yet. The numbers will be quite significant to go on to get Long Covid now.” 32/

“The other thing is vaccination, so this graph takes account of the reduced risk which I’m just about to talk about, that we’ve identified after vaccination. But the booster vaccination we think that probably has an additional helping affect to reduce the effect of Long Covid”33/

“And that’s not taken into account in this graph, even if Omicron was half as likely to lead to Long Covid as Delta, even if the booster vaccination has some effect. We’re still going to see really substantial numbers of people with Long Covid going forward.” 34/

“The story is certainly not over. Putting these together I think it likely that the 1.3 million estimate may have been a slight overestimate in December, but right now it’s probably going to be an underestimate. The numbers are still going to be very large.. 35/

“..and will almost certainly have increased with Omicron. Do we know if vaccines reduce the risk of Long Covid? We published a paper last October looking at the first couple of months after the second vaccination and comparing to people who are unvaccinated.” 36/

“So we took a case control analysis and saw a reduced odds ratio approximately halving risk in people who were double vaccinated, compared to matched unvaccinated controls. That’s taking account of quite a number of other factors that we think affect Covid risk like age etc” 37/

“Since then we’ve published that paper, we’ve been looking quite carefully at what happens over time with the second vaccine and we have seen some instances which we haven’t published yet, of a slight waning of that protectiveness of the second vaccine, over time.” 38/

“Not diminishing back to baseline. Then we’ve looked at boosters and we haven’t published this yet but we see that the booster vaccination appears to be reducing the risk again, at least with Delta but we can’t say yet with Omicron.” 39/

“I think that it’s really good we’ve had a vaccine rollout in terms of prevention on Long Covid is going to be really super important and we encourage everyone to come forward for their booster vaccination for this purpose.” 40/

“The last question that you’ve asked is - is there a difference in recovery between those who were hospitalised and those who were not? That’s something which is clearly evident from the papers you can see that are reviewing the literature that there’s a significant risk.. 41/

“I just thought I’d show you this study from one of the national core studies which is cohorts with TwinsUK. Within our cohort we’ve got 1627 people with Covid across the pandemic so far. As Danny’s pointed out there are different waves, different strains, things like that.” 42/

“But we can divide them off. Roughly we can’t see major differences here in that. About 30 of them were hospitalised (2%) that’s about the right rate. And you can see it’s much greater risk of having symptoms for more than 12 weeks in hospitalised groups than in.. 43/

“..non-hospitalised groups. In fact, much greater risk than in having more than 12 months of symptoms for people who were hospitalised. I think it’s undoubted that that’s a key factor, as I said at the beginning. 44/

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