Meaghan Kall Profile picture
Epidemiologist @UKHSA, mom, wife. Born 🇺🇸 Migrated 🇬🇧. Tweet about HIV & COVID-19. #Nature10 scientist. 🏳️‍🌈 Personal account, obvs.
Dec 6, 2023 5 tweets 2 min read
NEW: @UKHSA COVID-19 Variant Prevalence and Growth Rates

✅ JN.1 has been designated variant V-23DEC-01 due to increasing sequence prevalence in the UK and internationally.

gov.uk/government/pub…
Image JN.1 is a BA.2.86 sub-lineage (BA.2.86.1.1), which contains the L455S mutation in Spike, known to aid immune evasion.

There are currently 223 cases in England. Image
Aug 18, 2023 11 tweets 4 min read
NEW: @UKHSA variant risk assessment just published

⚠️ BA.2.86 designated a variant V-23AUG-01

gov.uk/government/pub…
Image Been a while since I have done a Friday night data drop thread!

But important to note this is a risk assessment, rather than a data report, due to limited numbers of sequences (6 cases in 4 countries at time of publication)
Aug 2, 2023 6 tweets 3 min read
NEW: @UKHSA COVID-19 Variant Prevalence and Growth Rates published

EG.5.1 is declared a variant (V-23JUL-01)

https://t.co/gqVsvmqD63gov.uk/government/pub…
Image EG.5.1 is a derivative of the Omicron XBB lineage, the currently dominant strain in the UK.

A variant is declared if it is growing in prevalence and is considered significant enough to justify further characterisation. Image
Apr 26, 2023 14 tweets 7 min read
ICYMI: @UKHSA published a new COVID-19 variant technical briefing

🧬 XBB.1.16 update and designated variant V-23APR-01

assets.publishing.service.gov.uk/government/upl… Image Current variant landscape🇬🇧

🔺XBB lineages dominate, now over 70% of sequenced cases

🔺XBB.1.5 led the takeover of BQ.1 and CH.1.1 earlier this year

🔺 XBB.1.16 (in pink below) is a small but increasing fraction

(Context will be relevant later on...) Image
Jan 27, 2023 13 tweets 7 min read
ICYMI: 🏴󠁧󠁢󠁥󠁮󠁧󠁿 GOV.UK Dashboard has changed how it presents COVID-19 deaths

@ONS death certificates are now the leading measure, replacing deaths within 28 days

This is because 28-day deaths is no longer a good proxy for COVID-19 deaths. A short thread🧵 This stems from a joint analysis between @UKHSA and @ONS, led by the brilliant @giulia_seghezzo

We have been monitoring how closely the 28-day deaths tracks COVID-19 death certificates.

khub.net/documents/1359…
Jan 16, 2023 18 tweets 10 min read
NEW: @UKHSA Variant Technical Briefing 49

🔘 XBB.1.5 and CH.1.1 designated variants

🔘 BQ.1 severity and VE estimates

assets.publishing.service.gov.uk/government/upl… Start with overall variant picture for England to 1 Jan:

This is Omicron soup. 🍜 Each colour a different Omicron lineage.

BQ.1.1 in light purple 🟣 is the most common at 51% of cases

CH.1.1 in yellow 🟡 is 20% and growing

XBB.1.5 in dark red 🔴 is 4.5% and growing
Jan 15, 2023 20 tweets 5 min read
Did healthy young people ever die suddenly before the COVID-19 vaccine? Someone should look into this. Just asking questions. #truthseeker I did my own research.

The answer is yes.

You just didn’t see it in the news.
Jan 10, 2023 5 tweets 3 min read
With so much vaccine misinfo on Twitter these days, remember 💭

Nobody denies that vaccines can have serious side effects.

The question is how severe and how often they occur compared to effects of infection.

For adults COVID vaccines have always been safer than infection.💉 The benefit of COVID vaccines for kids (esp under 12) has been hotly debated because it’s not crystal clear that the benefits outweigh potential risks.

But remember — that’s because severe COVID-19 AND vaccine complications are VERY RARE in kids.
Jan 6, 2023 5 tweets 2 min read
New @CDCgov variant data is out

A good time to remind everyone the last 3 WEEKS numbers are a ‘nowcast’ (modelled, not real data)

Last wk 41% estimate of XBB.1.5 has been revised down to 18% (to 31 Dec)

The curse of the overestimated early growth rate strikes AGAIN. CDC has update the page with a nice clear explainer of their nowcasting methods ➡️ cdc.gov/coronavirus/20…
Jan 5, 2023 5 tweets 1 min read
Too busy to tweet so yeah that’s how covid and flu are going at the moment 😔 I kid you not an hour after tweeting this my son did this…

It’s gonna be a long night. 🥱 Image
Dec 29, 2022 5 tweets 2 min read
When people ask, will the next COVID variant come from China? This is my answer👇

A variant borne of high transmission in a naive population will not be immune evasive. It does not need to be. It will not succeed in a population with lots of immunity of different flavours. A new immune-evasive variant, eg borne of chronic infection or zoonoses has a fair chance emerging from a high transmission setting BUT takes 6-18 months to appear.

In fact, such a variant could come from anywhere w/community transmission & immunosuppression or animal reservoir.
Dec 23, 2022 14 tweets 8 min read
NEW: COVID-19 and Flu surveillance report (+ respiratory viruses!) 🦠

This week worth a thread🧵

Loads of bugs circulating in England at a time when NHS is under immense strain

COVID-19 is ⬆️
Flu is ⬆️
hMPV is ⬆️
Strep A is ⬆️
RSV is ⬇️

assets.publishing.service.gov.uk/government/upl… This is no surprise if you’ve been following UK winter viral data, or… left the house.

Now a sort of crescendo approaches.

We are concerned about a twindemic but reality is more complex with multiple viruses co-circulating at higher than normal levels for this time of year.
Dec 21, 2022 6 tweets 4 min read
NEW: @UKHSA study on #StrepA in kids ⤵️

Nasal flu vaccine DOES NOT increase risk of strep A in kids 💉

Flu infection can cause strep A as secondary infection. 🦠

Flu vaccine can prevent flu, and indirectly prevent strep A infection. #GetVaccinated

medrxiv.org/content/10.110… You may have seen rumours circulating widely on TikTok, Facebook and Twitter

That nasal flu vaccine (the live attenuated vaccine [LAIV]) used in children causes strep

These unfounded rumours do nothing but stoke fear in responsible parents who want to protect their children
Dec 16, 2022 13 tweets 5 min read
This week The Sun reported that Wales is a scarlet fever ‘danger spot’ 🚨‼️

But all is not what it seems. Why?

Tl;dr: don’t trust case numbers alone.

A mini infectious disease surveillance Tweetorial 🧵 ImageImage As an infection metric, case data should not be interpreted in isolation.

Especially for an illness caused by a common infection that is rarely formally diagnosed.

As scarlet fever is usually mild & self-limiting, these cases are a small fraction of the true number of cases.
Oct 20, 2022 20 tweets 10 min read
Do you know an older person (50+) who is hesitant about getting COVID-19 and Flu jabs this winter? 💉

It’s important that they do - and here’s what they should know.

Spread the word ⤵️ Start with some facts.

First, COVID-19 hasn’t gone away.

Ok. Twitter knows this. But in real life people constantly ask me if it is still a thing? Because it’s not in the news anymore.

COVID-19 is here, for good.

In fact, the predicted winter wave of COVID-19 is underway… Image
Oct 16, 2022 5 tweets 1 min read
The fact is that COVID-19 transmission dynamics are a lot more complicated than they used to be.

Population immunity profile is heterogenous+++

Modellers must be quite brave (or foolish) to attempt predictions at this stage. Time was, a new variant just be more transmissible to succeed.

Now, with
• ~90% of the UK population ever infected
• 90% vaccinated (age 12+)
• 70% boosted (age 12+)

A new variant has a much more complicated immune landscape to overcome
Oct 7, 2022 15 tweets 8 min read
NEW: @UKHSA COVID-19 Variant Technical Briefing 46

🔘 Update on Omicron lineages BA.2.75*, BF.7, BQ.1*

assets.publishing.service.gov.uk/government/upl… Eagle eyed variant watchers 🔎 have recently spotted a handful of Omicron lineages emerging from a deep field of runners.

Among these are:
• BQ.1 (+ child BQ.1.1)
• BA.2.75 (+ child BA.2.75.2)
• BF.7

Catchy names, I know, but bear with me…