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Marc Lipsitch

@mlipsitch.bsky.social
1.9K followers 461 following 70 posts

Professor of Epidemiology Harvard Chan SPH, Director, @ccdd-hsph.bsky.social. Views my own.

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Marc Lipsitch @mlipsitch.bsky.social · 06/10/2025
cisac.fsi.stanford.edu/content/cisa... In my new role at @stanfordcisac.bsky.social, I'm recruiting for a postdoc to define how benefits of risky research should be evaluated. w Tony Mills of @notredame.bsky.social . #philsci #biosecurity #scipolicy
cisac.fsi.stanford.edu
CISAC Fellowship Program
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Marc Lipsitch @mlipsitch.bsky.social · 09/09/2025
Key points: A popular "hazard difference" estimator for averted outcomes is biased, but an unbiased one can be calculated from status-based aggregated data (knowing y/n vaccinated for those with and without the outcome). For avertible outcomes, this doesn't work; need to know dates of vaccination.
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Marc Lipsitch @mlipsitch.bsky.social · 09/09/2025
New preprint reporting a large piece of work by Katherine Jia to define estimands and estimators for direct impact of vaccines with arbitrary rollout schedules arxiv.org/abs/2509.05508 with Alyssa Bilinski, @chrisboyer.bsky.social and me
arxiv.org
Defining and Estimating Outcomes Directly Averted by a Vaccination Program when Rollout Occurs Over Time
During the COVID-19 pandemic, estimating the total deaths averted by vaccination has been of great public health interest. Instead of estimating total deaths averted by vaccination among both vaccinat...
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Christophe Fraser's Group @christophraser.bsky.social · 26/08/2025
New paper: we argue that a promising approach for studying mpox vaccine effectiveness in Central Africa to incorporate mpox vaccination + testing data into existing cohort studies, especially those for HIV/STIs. www.thelancet.com/journals/ebi...
thelancet.com
Clade I mpox vaccination: strategies for deployment and evaluation
Clade I mpox continues to spread in Central Africa with no sign of abating,1 however very few doses of vaccine have been deployed. Mpox vaccination strategies using either of the licenced vaccines, MV...
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Marc Lipsitch @mlipsitch.bsky.social · 26/08/2025
There is surely some basic biology benefit to gain. But the 100s of millions spent were justified with pandemic prevention/response as part of it, and the vaccine part of that doesn't hold water.
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Marc Lipsitch @mlipsitch.bsky.social · 26/08/2025
The fact that WIV1 and HKU1 were used by Moderna doesn't mean that they were central to the science; I'm no patent expert but I guess patent applicants want to cover as many applications (eg viruses) as possible for commercial reasons. Unclear to me if using them fundamentally changed conclusions.
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Marc Lipsitch @mlipsitch.bsky.social · 26/08/2025
On the substance of your points, I am not sure about the "not dangerous because the worst viruses are already at the interface" -- depends if ecological encounter opportunities are rate-limiting, which I think we often don't know.
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Marc Lipsitch @mlipsitch.bsky.social · 26/08/2025
one argument supporting a type of research may be weak while another is stronger, or research may be both dangerous and useful (or safe and not useful) and taking points one at a time helps to keep the questions separate.
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Marc Lipsitch @mlipsitch.bsky.social · 26/08/2025
Thanks @acritschristoph.bsky.social for these thoughtful comments. Apart from space and time, one reason we didn't address the other arguments was that I think it's important to consider arguments separately to reduce pressure to form "sides" -- ...
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
There may be other justifications for the expense and risk incurred by such prospecting efforts, but vaccine development is not a strong one. Pathogen identification at the human interface (in spillover cases) and efforts to avoid or remediate human drivers of spillover risk may be more efficient.
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
For Marburg, a reservoir is known, but serious efforts at countermeasures have been spurred by human outbreaks. We conclude that virus prospecting is neither necessary, sufficient, nor particularly feasible as a driver for medical countermeasure (at least vaccine) development.
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
Last, we take a look at detailed timelines of human and animal isolation of filoviruses (ebolavirus spp. and Marburg) and note that in ebolaviruses, animal reservoirs have not been confirmed but countermeasure development has followed large human outbreaks.
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
Then we identify the large number of targets for which vaccines are arguably more urgent than for any virus known only in non-human hosts: the 26 families of viruses known to infect humans. Among these, there are no vaccines approved for even a single member of 10 of the 26 families.
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
Then we note that most major virus outbreaks of the 21st century have been caused by viruses first discovered in humans. Next, we show that recent priority pathogen lists for countermeasure development have contained known human pathogens but shown little relationship to virus discovery in wildlife.
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
First we note that historically, finding a novel virus in animals before the first known human outbreak did not in any case spur countermeasure development. Poignant examples are Zika (1947 in animals, 1952 in humans, vaccines only much later) and monkeypox (1958-1970, vaccine R&D only recently).
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
In it we asked if prospecting for novel viruses in wildlife is justified, as often asserted, as a means to speeding the development of countermeasures against emerging infections. We find little evidence that it is.
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Marc Lipsitch @mlipsitch.bsky.social · 25/08/2025
Very pleased to share this newly published work with Aishani Aatresh, part of her exceptional Harvard undergrad thesis. journals.asm.org/doi/10.1128/... .
journals.asm.org
What is the relationship between viral prospecting in animals and medical countermeasure development? | mBio
Sampling in animal populations to detect novel viruses before they infect humans has been a major activity justified by several considerations, notably by the idea that finding such viruses will stimu...
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Marc Lipsitch @mlipsitch.bsky.social · 14/08/2025
Good to get them <65 in advance of Medicare denying payment for progressives
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CCDD @ccdd-hsph.bsky.social · 21/07/2025
Check out "Are We Prepared for the Next Pandemic?"- CCDD Director, @mlipsitch.bsky.social's conversation with Sam Harris, host of the Making Sense podcast. www.samharris.org/podcasts/mak...
samharris.org
Sam Harris | #425 - Are We Prepared for the Next Pandemic?
Sam Harris speaks with Marc Lipsitch about pandemic preparedness.
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Elizabeth Warren @warren.senate.gov · 30/06/2025
Republicans, before you vote to close 1 of 4 nursing homes, can you update us on where those people will go? Maybe call a few seniors in your state and go over plans for where they go next? Or call the son whose dad has dementia and tell him how he can be a full-time caregiver?
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CCDD @ccdd-hsph.bsky.social · 24/06/2025
A new study by Julia Deichmann, @mlipsitch.bsky.social and collaborators at the Sheba Medical Center, Israel uses mathematical modeling to predict antibody kinetics and duration of protection against SARS-CoV-2 following vaccination using sparse serological data. Read it here at bit.ly/43XY9mK
bit.ly
Predicting antibody kinetics and duration of protection against SARS-CoV-2 following vaccination from sparse serological data
Author summary Vaccination against SARS-CoV-2 has played a key role during the COVID-19 pandemic to lower transmission rates and reduce the number of severe cases. This is due to a vaccine-induced ris...
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CCDD @ccdd-hsph.bsky.social · 25/06/2025
New tool for pangenome analysis! CLARC refines bacterial gene clusters using functional annotation + linkage—not just sequence. New publication by @indragon.bsky.social & collaborators, advised by @mlipsitch.bsky.social & @billhanage.bsky.social. Read more at bit.ly/4ek0Y51
bit.ly
Linkage-based ortholog refinement in bacterial pangenomes with CLARC
Abstract. Bacterial genomes exhibit significant variation in gene content and sequence identity. Pangenome analyses explore this diversity by classifying g
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Marc Lipsitch @mlipsitch.bsky.social · 20/06/2025
Deeply affecting article by an @hsph.harvard.edu PhD student denied the opportunity to graduate due to blanket exclusion of Sierra Leone citizens by the US Government. A very particular example of pointless cruelty by the US Government. www.theguardian.com/global-devel...
theguardian.com
What it’s really like … to know I’m going to miss my Harvard graduation because of Trump’s travel ban
Like many other international students I have had my educational dreams suspended without reason – and learned plenty about racism and resilience
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Marc Lipsitch @mlipsitch.bsky.social · 09/06/2025
There is a link for non-NIH individuals to sign in support. Already several Nobelists and others have
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Marc Lipsitch @mlipsitch.bsky.social · 09/06/2025
Remarkable open letter to the director from NIH staff on the health, financial,academic freedom, and other impacts of changes at the agency. www.standupforscience.net/bethesda-dec...
standupforscience.net
Bethesda Declaration — STAND UP FOR SCIENCE
Support NIH Staff Now!
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Michael Baym @baym.lol · 31/05/2025
The goal is plainly and literally to cut the number of people involved in basic science in the US by 70%
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Ferric Fang, MD @fangferric.bsky.social · 31/05/2025
"The policy’s narrow-mindedness will make America small again.” I am simply at a loss to express how stupid this is. www.nytimes.com/2025/05/30/b...
nytimes.com
Denying Visas to Chinese Students Could Backfire on America
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Marc Lipsitch @mlipsitch.bsky.social · 29/05/2025
Great piece by @hsph.harvard.edu colleague Maitreyi Mazumdar about how NIH's evisceration of overseas research collaborations harm the US as well as the partner countries www.bostonglobe.com/2025/05/29/o...
bostonglobe.com
NIH cuts have doomed my research in Bangladesh — but US citizens will pay too - The Boston Globe
Global partnerships have led to major scientific breakthroughs and saved millions of lives. Now, those collaborations are in jeopardy.
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Marc Lipsitch @mlipsitch.bsky.social · 28/05/2025
Thanks Dani Blum @nytimes.com for breaking down the science on kids, pregnant people, and COVID shots www.nytimes.com/2025/05/27/w...
nytimes.com
The C.D.C. Now Says Healthy Kids Don’t Need Covid Shots. Is That True?
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Marc Lipsitch @mlipsitch.bsky.social · 27/05/2025
US health agencies like CDC and NIH and FDA remain full of dedicated and exceptional scientists and health professionals doing the right thing for public health. But this example shows they can be overruled by an exceptionally unqualified secretary of HHS.
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Marc Lipsitch @mlipsitch.bsky.social · 27/05/2025
I'm fortunate to live in a state with a high-quality health department that provides information based on science. For those who don't I recommend Canadian www.canada.ca/en/public-he... or UK www.gov.uk/government/o... advice.
canada.ca
Public Health Agency of Canada - Canada.ca
Public Health Agency of Canada
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Marc Lipsitch @mlipsitch.bsky.social · 27/05/2025
As the quality of health advice becomes more politicized and arbitrary, and less science-based Americans are going to have to turn to state health officials (some of them) or other countries for good advice.
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Marc Lipsitch @mlipsitch.bsky.social · 27/05/2025
The Department of Health and Human Services has a process for making and updating recommendations like this, using expert scientists and clinicians. RFK is deliberately putting Americans' health at risk and sidestepping good science for political reasons.
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Jasmin Abdel Ghany @jasminabdelghany.bsky.social · 26/05/2025
The Demographic and Health Survey (DHS) Program was central in improving the evidence base for health policies and interventions, particularly in Sub-Saharan Africa and Central & Southern Asia - figure by @aasli.bsky.social. Our preprint on the termination of the DHS Program: osf.io/preprints/so...
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Bailey Bowcutt @baileybowcutt.bsky.social · 22/05/2025
I'm a current Harvard graduate student and I found out today that I had my NSF GRFP terminated without notification. I was awarded this individual research fellowship before even choosing Harvard as my graduate school
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Marc Lipsitch @mlipsitch.bsky.social · 22/05/2025
Please consider a comment today if you are in the US. See the advice (shared from an email I received) in the follow-up posts below this one. Tomorrow is the deadline. This is an important part of scientific freedom in this country.
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Marc Lipsitch @mlipsitch.bsky.social · 22/05/2025
If thousands of scientists say that political interference with grants assessment is going to destroy the scientific integrity of federal grants, the agency will have to explain why the rule doesn’t do that (which it can’t because this is precisely why the new regulation is being instituted).
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Marc Lipsitch @mlipsitch.bsky.social · 22/05/2025
The agency must act in a rational way, providing reasons for not taking particular objections into account and justifying its proposal in ways that are legally acceptable.
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Marc Lipsitch @mlipsitch.bsky.social · 22/05/2025
By law, the proposing agency (in this case, the office of personnel management headed by Project 2025 coordinator Russell Vought) must take comments into account and respond to them, thereby forming a record that can be challenged in subsequent litigation.
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Marc Lipsitch @mlipsitch.bsky.social · 22/05/2025
Time Sensitive: Public comment on Schedule F (removing civil service protections for many federal employees INCLUDING THOSE WITH AUTHORITY OVER GRANTS) ends tomorrow. Notice is here: www.govinfo.gov/content/pkg/... . Comment here (green button) www.federalregister.gov/documents/20... .
govinfo.gov
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Marc Lipsitch @mlipsitch.bsky.social · 22/05/2025
A partial solution is to post preprints of everything (so far still free). But the junior scientists who lead much of this work need peer-reviewed publications (and sadly the name of the journal still matters way too much in evaluations) so this solves only part of the problem.
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Marc Lipsitch @mlipsitch.bsky.social · 22/05/2025
An easily overlooked consequence of research funding cancellations: completed research these days requires hundreds to several thousand dollars to be published due to publication fees from journals. Without support for these fees many pieces of scientific work will be near invisible.
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Marc Lipsitch @mlipsitch.bsky.social · 21/05/2025
This is pure authoritarianism. www.nytimes.com/2025/05/21/u...
nytimes.com
If Justice Dept. Can’t Prosecute Trump’s Foes, It Will ‘Shame’ Them, Official Says
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Stand Up for Science! @standupforscience.net · 19/05/2025
🎓 The GOP’s reconciliation bill is a direct hit on higher ed: – $351B in cuts education & workforce programs – eliminating subsidized student loans – Taxes on scholarships & endowments – & more. ACE calls it a “full-out assault” on access to college. Read below ⬇️ www.acenet.edu/News-Room/Pa...
acenet.edu
House Reconciliation Bill Targets Higher Education with Deep Cuts and Tax Hikes
A budget reconciliation bill advancing in the House of Representatives proposes hundreds of billions of dollars in cuts to student aid, imposes new taxes on colleges and universities, and jeopardizes ...
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Linda Barlow @bizzarlow.bsky.social · 20/05/2025
Proposed cut to NIH for fiscal 2026- $18 billion www.whitehouse.gov/wp-content/u...
whitehouse.gov
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Marc Lipsitch @mlipsitch.bsky.social · 20/05/2025
Important public service reporting from @statnews.com on how people are getting their NIH grants reinstated www.statnews.com/2025/05/19/r...
statnews.com
Scientists are pushing to get their grants reinstated — and some are winning
The grant termination letters say there are no appeals. Yet dozens of appeals have succeeded as biomedical researchers lobby and sue to restore funding.
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Megan Behringer @megbehri.bsky.social · 09/05/2025
Given that there are 435 voting members of Congress, I would have hoped for more than 25% of House members to support American innovation in science and technology. 112? That’s it? No one else wants answers?!?!
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Marc Lipsitch @mlipsitch.bsky.social · 24/04/2025
here's the modely version of Cox and Chao europepmc.org/article/pmc/...
europepmc.org
Europe PMCEurope PMC
Europe PMC is an archive of life sciences journal literature.
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Marc Lipsitch @mlipsitch.bsky.social · 24/04/2025
Model-ish pubmed.ncbi.nlm.nih.gov/306628/ and its modern update pubmed.ncbi.nlm.nih.gov/37669395/ Also model-ish pubmed.ncbi.nlm.nih.gov/28568016/ pubmed.ncbi.nlm.nih.gov/26066486/ Haven't read but hear great things www.biorxiv.org/content/10.1... pubmed.ncbi.nlm.nih.gov/37312496/
pubmed.ncbi.nlm.nih.gov
Innate immune responses yield tissue-specific bottlenecks that scale with pathogen dose - PubMed
To cause infection, pathogens must overcome bottlenecks imposed by the host immune system. These bottlenecks restrict the inoculum and largely determine whether pathogen exposure results in disease. I...
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