I've always found it very unhelpful that 'self-isolation' is used to refer to both isolation and quarantine, but the distinction is now becoming increasingly important... 1/
To recap, isolation is for people who are confirmed to be infected; quarantine is for people who currently seem healthy but may be infected. A stay-at-home order is basically a large, untargeted quarantine (some countries even call it 'community quarantine'). 2/
As vaccines reduce infections/transmission, countries are re-evaluating approaches to disruptive quarantine, whether for travellers or contacts of cases (e.g. in US: cdc.gov/coronavirus/20…). However, we need to be careful about jumbling isolation and quarantine together... 3/
Getting tested & isolating and when you have symptoms is one of biggest ways to reduce overall transmission. If done well, it's one of the most efficient, because it's targeted only at people known to have the virus. And crucially, it can flag emergence of new variants. 4/
If the message becomes 'fully vaccinated people don't need to self-isolate', there's a real risk that we'll see a notable increase in transmission - and lose vital situational awareness about variants - in the confusion between isolation and quarantine. 5/5

• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Adam Kucharski

Adam Kucharski Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @AdamJKucharski

2 Jul
Schools, workplaces, pings from COVID app… Having high UK case numbers over summer will have huge implications for quarantine burden. A few thoughts… 1/ bbc.co.uk/news/business-…
Because vaccines reduce onwards transmission, contacts are becoming less risky on average - which means that for a given value of R, each case will typically have far more contacts than they would have had last year. 2/
Under pre-pandemic contact patterns, a typical case will have 25+ contacts while infectious (thelancet.com/journals/lanin…). That’s a lot of people who could potentially be quarantined per case. 3/
Read 4 tweets
18 Jun
Any discussion of daily testing vs quarantine for contacts of cases in schools needs to address the key epidemiological question: if a child in a school tests positive, what do you do next? 1/
Encouraging ventilation etc. to reduce transmission risk is important, but you still have to decide what to do about a positive result. Do you quarantine their contacts or not? 2/
If you decide to abandon quarantine because you think ventilation etc. has sufficiently reduced risk, then this still means accepting higher transmission risk than if quarantine had remained in place. 3/
Read 8 tweets
11 Jun
How long could UK cases continue to rise? And how might hospitalisations increase alongside? A thread... 1/
Despite relatively high vaccination rates compared to other countries, cases are growing and in many areas R is now above 1.5. Remember, immunity is already 'priced in' to this number - without vaccination and the social distancing still in place, R would be *much* higher. 2/
If R is 1.5 and contacts/control remain the same, then we'd need remaining part of the population who could potentially spread COVID to shrink by at least 33% before R drops below 1 & epidemic peaks. This would require additional immunity, either from infections or vaccines. 3/
Read 9 tweets
5 Jun
A common Q: “how can COVID hospitalisations in UK still grow if vaccine % high?” Answer: look at the data. Average was ~120 daily COVID admissions over past week. These would have been infected about 2-3 weeks earlier, when case numbers ~2000 per day. This shows two things... 1/
First, there was still a group at risk of hospitalisation a few weeks ago. And second, this risk was large enough to show up as hundred of admissions in recent data, even though cases were at relatively low levels. 2/
So the key question here: if case numbers were to grow X times larger, why wouldn’t hospitalisations also grow X times larger? 3/
Read 4 tweets
25 May
One thing that has hugely shaped countries' response to COVID, and which I don't think gets enough discussion: genuine constraints and perceived constraints. A thread... 1/
Some apparent local constraints have persisted throughout the pandemic. For example if you look globally, there are still notable differences in approaches to surveillance and quarantine... 2/

It's worth reading these papers on the response in Taiwan (jamanetwork.com/journals/jama/…) and Korea (jamanetwork.com/journals/jama/…). Should more countries include these data-intense approaches in future pandemic plans? Or does reluctance to date reflect an immovable constraint? 3/
Read 9 tweets
23 May
Preliminary UK data on vaccine effectiveness against B.1.617.2 (originally detected in India) now available: khub.net/documents/1359…. A few things to note... 1/
First and foremost, it’s another reminder that *second doses matter*. By Aug/Sep, UK will be in much better position against B.1.617.2, but there’s a risk of substantial transmission in meantime as things reopen. 2/

Also remember that when vaccine effectiveness high, small absolute differences can have big effect. E.g. a drop from 95% to 90% would double number at risk (and probably more than double outbreak size given non-linear nature of transmission). 3/
Read 6 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!