And we're off!

Kudos to @malar0ne for organizing this.
First up: a discussion of the "let the virus" rip strategy pushed by the Great Barrington Declaration.

GBD wanted herd immunity from natural infection.
They influenced policy:

"From Oct 2020-Jan 2021, we allowed 270,000 people to die in the US," said Prof Lauren Ancel Meyers
Fascinating discussion of "overshoot," as described by @CT_Bergstrom & @nataliexdean. Prof Meyers says that Britain's strategy of regular testing is valuable in this context.…
Prof Meyers shows data on Austin, Texas, showing that communities with higher social vulnerability have a higher attack rate AND are less likely to have vaccination access & high coverage. She says we need to tackle this inequity to reach vaccine herd immunity.
Dr Meyers discussed a study she co-authored. GBD is based in part "on unpublished research that suggests low herd immunity thresholds (HITs) of 10-20%. We re-evaluate these findings & correct a flawed assumption leading to COVID-19 HIT estimates of 60-80%"…
Next speaker is Prof Julie Parsonnet, who discusses historical studies on herd immunity, in humans & other animals.
Herd immunity against several infectious diseases in the US was only achieved by high efficacy vaccines, says Dr Parsonnet (smallpox, polio, measles).
"I can't think of any disease where on a large scale we've achieved herd immunity without a vaccine," says Prof Parsonnet.
She now pivots to the global picture.

"We live in a world where there are a LOT of unvaccinated people," says Prof Parsonnet.

We won't end the pandemic unless we address this.
Next up is Prof Marc Lipsitch. He'll discuss "Herd immunity: necessary, sufficient or possible?"
He kicks off by saying that while we often focus on R0 (which could be up to 6 in some settings for COVID-19), we should also be considering vaccine effectiveness against transmission.
Here he answers his questions:
Vaccines work very well in the most at-risk (e.g. elderly), which he says makes reaching herd immunity itself less important. The study in Israel that he co-authored is very encouraging:…
Prof Lipsitch notes that the data so far show that vaccines do reduce transmission, which is very encouraging.

But to reach vaccine herd immunity, based on what we know so far about the magnitude of this reduction in transmission, we *may* need to vaccinate everyone, he says:
Even if we reach the herd immunity threshold in the US and other rich nations, the virus will continue to circulate worldwide, says Prof Lipsitch. So it won't be enough JUST for the US to reach the HIT.
Global inequity in vaccination; vaccine hesitancy; evolution; and immune waning, he says, will be ongoing challenges to reaching global vaccine herd immunity.
Last panel presentation is from Prof Rustom Antia.

He notes that for endemic human coronaviruses (which don't tend to cause severe disease), immunity from natural infection wanes over time.…
Prof Antia et al's Science paper:

"The transition from epidemic to endemic dynamics is associated with a shift in the age distribution of primary infections to younger age groups, which in turn depends on how fast the virus spreads."
"Longer-lasting sterilizing immunity will slow the transition to endemicity. Depending on the type of immune response it engenders, a vaccine could accelerate establishment of a state of mild disease endemicity."
His key unknowns for the transition to benign endemicity:

Q1. Is Brazil's push for herd immunity through natural infection (the GBD approach) the right strategy?

Prof Lipsitch: 1 flaw is that we don't know how protective herd immunity from natural infection is; natural immunity is accomplished with a lot of deaths
Q2. On CATS and herd immunity😿

"Cats are sociopaths and want to kill us," says Dr Parsonnet

(hey, I am just the MESSENGER of this panel).

She was joking. She's not worried about cats getting in the way of humans reaching vaccine herd immunity.
Q3. Do superspreader events affect the HIT?

Dr Meyers: they can make it difficult for our interventions to be effective. It's a challenge to mitigation. It depends on the REST of the population (i.e. are these isolated events but on top of little background transmission?)
Q4. Cross-protection against other coronaviruses: could this help us get to herd immunity for COVID-19?

Marc Lipsitch: there's no evidence that past infection with a different coronavirus provides reliable protection against COVID-19 infection
Q5. Do variants of concern mean that the herd immunity threshold is now higher?

Dr Lipsitch: if VOC is more transmissible (e.g. B.1.1.7), yes, the HIT is higher
Dr Meyers: HIT does have modifiers e.g. durability of immunity, evolution of variants, etc.
Dr Meyers: masking is crucial. Keep masking as it will allow us to get to herd immunity faster. Testing can be HUGELY helpful (e.g. see the UK's approach) as it can reduce transmission *if* people isolate & are supported to isolate (@BillHanage has made this point too).
Dr Parsonnet: we need to "press ahead" and vaccinate folks as fast as possible. The mRNA vaccines may be adaptable to variants. We have a window right now to really push to get folks immune. Use masking to reduce susceptibility while also scaling up vaccines. Protect people now!
Q. What's the value of testing?

Dr Meyers: there are lots of really great examples of using testing to stop cases at the school gate! We published a study on testing & isolation: when R0 is over 1, this is VERY cost effective.

Here's her study:…
Q. What's the biggest misconception you've seen about herd immunity?

Dr Lipsitch: when people talk about reaching herd immunity, they think it is 'yes' or 'no,' but every little helps and it is not about being on or off. Lower transmission is better! Herd immunity is continuous
Dr Parsonnet: people think the vaccines will solve all problems & nil else will benefit. This is false. We need a "whole toolbox" of efforts: need to wear masks, avoid superspreader events, etc. The vaccine is also not perfect.
Dr Antia: vaccines can be very effective even if they don't engender vaccine herd immunity, as they reduce transmission.

Dr Meyers: we have 'hot seasons' of COVID-19 in the future, & we may need periods of interventions e.g., masks in winter if cases rise.
Dr Meyers: vaccines are going to transform COVID-19 into an endemic illness, like seasonal flu.

We as scientists need to study: what would indicate to us that the disease has transitioned to low endemicity?
Dr Meyers: we as scientists can help guide and shape policy on things like masking & testing. We know these work, & can guide the community on when they are needed the most.
Marc Lipsitch: there's pretty good evidence that people with past infection make a great antibody response to a single dose of vaccine. That's why Israel is vaccinating those who were previously infected.
Q: what are you optimistic about?

Lipsitch: many nations eliminated COVID-19 without a vaccine. It can be done. It is implausible that the US can achieve this, he says, perhaps with the exception of Hawaii.

He says vaccines will at least 'defang' the pandemic in rich nations
Prof Meyers: I'm hopeful about vaccines. Locally, our hospitalization data suggests that lengths of stay have fallen, so it looks like we're already defanging it. Mortality rate has fallen.
Antia: eradication is not possible, but low endemicity is possible. We'll probably need 2 vaccinate adults repeatedly 4 low endemicity

Dr Parsonnet: the no. of patients in our hospital is way down. I'm hopeful because there's political will to deal with COVID-19, unlike in 2020
OK folks, that's it for me. I typed as fast as I could & did my best to find the papers that the panelists mentioned. Over 750 people listened in.

CONGRATS TO @malar0ne for a world class panel!

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More from @GYamey

8 Apr
The people have spoken! Y'all wanted a playlist of songs about immunology & vaccines 💉

I dedicate my list to the many immunologists & virologists who I've learned so much from during COVID-19, such as @VirusesImmunity @florian_krammer @andrew_croxford & @angie_rasmussen

1/11 Image
We begin with a special track arising from a @PENamerica campaign:

"Antibodies" by Vietnamese songwriter/activist Mai Khôi & Lebanese vocalist Hamed Sinno

They "navigated profound risks to share their voices for the song" []

Next up: the Oakland, California-based band Tower of Power giving us "Soul Vaccination."

This track is from their 1973 self-titled 3rd album.

"Soul vaccination say roll up your sleeve
Cuz if you ain't buggin' you might still got the disease"


Read 11 tweets
8 Apr
Very excited to have two guest lecturers from @RTI_Intl in my class today, Molly Chen & Elizabeth Fitch, who will discuss: "Measuring large-scale change: how to evaluate policy" 🔎

Interested in the readings for the class?📖📖📖

This thread has them 1/n
UN Resolution Highlighting Evaluation Capacity Building for the Achievement of Development Results at Country Level

WHO Framework and Standards for Country Health Information Systems, 2nd edition

USAID CLA Case competition finalist “Using CLA to Improve Malaria Data Quality and Decision Making in Guinea

Zambia National Health Strategy Plan (2017-2021)

USAID Evaluation Policy

Read 4 tweets
7 Apr
The American jazz trumpeter Freddie Hubbard was born on this day in 1938🎺

His beautiful music enriched our lives.

One of his masterpieces was Red Clay. I pay tribute by sharing my 5 favorite ever versions of this stone cold classic.

The original 1/5

Mark Murphy's vocal version 'On the Red Clay' is 🎆🎇🔥

From his '75 album Mark Murphy Sings.

Randy Brecker on🎺

"Scream door slappin' somewhere on a side porch
A sleepy morning way out in the boon docks
Stories are being told on the red clay"


Now a musical 'holy grail,' impossible to get hold of until Germany's Tramp Records reissued it.

This cover is by Gunn High School Jazz Reunion.

INTENSE soulful funk-adjacent jazz. That bass! The vocals by Randy Greer! Stanley Jordan guitar solo!

Read 5 tweets
6 Apr
Musical interlude.

I've been listening to a LOT of Abby Lincoln & Max Roach, one of the finest musical duos in history

It got me wondering: which other musicians who are/were in a romantic relationship produced great music? Let me know who I missed
Honestly, up there with Lincoln & Roach it HAS to be Doug & Jean Carn. Their 1973 album Revelation is one of my favorites of theirs. The title track is 🔥🔥🔥


Folks, I'm not going chronologically, I'm all over the map.

Next up is one of the world's best electronic duos, Matmos: Martin Schmidt & Drew Daniel.

I once interviewed them for a piece I wrote in @bmj_latest! (…)


Read 11 tweets
31 Mar
At the age of 80, Pharoah Sanders, one of the world's greatest living musicians, just released one of his finest ever albums, "Promises"

This got me wondering: who else born before 1950 is still crushing it musically?

A thread of 10 of my favorites 1/11
I had to start of course with Marshall Allen, who is 96. I saw him perform a few years ago with the Sun Ra Arkestra in London, @gillespeterson's Worldwide Awards. He was ON FIRE. In 2020 they put out a great new album (their first in over 20 years) 2/11
Am I the world's biggest Grace Jones fan or is it my kid brother, @YameyDesigns, who had posters of her all over his bedroom as a kid?

She's 72 & is rumored to be releasing a new album any day now. Her most recent album (her 10th), came out in 2008 3/11

Read 11 tweets
30 Mar
I gave a talk last night @DukeU on R&D for neglected diseases.

Mini-thread of reflections 🧵

20 years ago I teamed up with @ElsTorreele on an editorial for @bmj_latest called "The world's most neglected diseases" […]

Have things changed since then? 1/n
Yes, we still have a LONG way to go. Our team co-authored a new study of the pipeline of candidate products for neglected diseases. There are still VERY few candidates for diarrheal diseases, salmonella infections, helminths & kinetoplastid infections 2/n
BUT, there has been notable progress over the last 20 years:

💲 Since 2007, the research group @PCuresResearch has tracked annual financing of R&D for these diseases. In FY2007, there was $2.7B in funding. In FY2018, funding reached $4B, a new high. 3/n
Read 9 tweets

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