Marc Veldhoen
@marcveld.bsky.social
Professor of Immunology 🇳🇱 🇬🇧
Lisbon, 🇵🇹
#Immunology
Time for Science, not silence
https://scholar.google.co.uk/citations?user=7vG1jLIAAAAJ&hl=en
https://orcid.org/0000-0002-1478-9562
threads.net/@marc_veld
mastodon.online/@marc_veld
Lisbon, 🇵🇹
#Immunology
Time for Science, not silence
https://scholar.google.co.uk/citations?user=7vG1jLIAAAAJ&hl=en
https://orcid.org/0000-0002-1478-9562
threads.net/@marc_veld
mastodon.online/@marc_veld
Pinned
Marc Veldhoen
@marcveld.bsky.social
· Nov 29
What will population immunity to SARS-CoV-2 look like in a post-vaccine world?
An updated outlook (2025)
marcveldhoen.substack.com
Five years of COVID taught us one thing: immunology didn’t fail, our public discourse did. My new Substack cuts through the noise with evidence, not ideology. If you want facts over fear, and science over spin, join here:
marcveldhoen.substac...
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marcveldhoen.substac...
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Reposted by Marc Veldhoen
New Substack: the myth that SARS-CoV-2 causes “premature ageing” of T cells.
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
The myth of SARS-CoV-2-induced premature T cell ageing
A critical look at the evidence
open.substack.com
January 17, 2026 at 2:13 PM
New Substack: the myth that SARS-CoV-2 causes “premature ageing” of T cells.
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
Reposted by Marc Veldhoen
A new preprint is being used to claim “persistent immune damage” after COVID. I’ve written a detailed scientific review explaining why that conclusion does NOT follow. Small cohort. Descriptive data. Big claims. This matters
open.substack.com/pu...
1/4
open.substack.com/pu...
1/4
Persistent Immune Dysregulation in Long COVID? A new pre-print
The preprint “Persistent Immune Dysregulation during Long COVID is Manifested in Antibodies Targeting Envelope and Nucleocapsid Proteins” by Rehman and colleagues (2025) proposes that individuals with Post-Acute Sequelae of SARS-CoV-2 infection (PASC or Long COVID) exhibit long-lasting alterations in humoral and cellular immunity characterised by elevated IgG against SARS-CoV-2 Envelope (E) and Nucleocapsid (N) proteins, skewed immune cell profiles, and an inflammatory cytokine milieu persisting up to six months post-infection.
open.substack.com
January 17, 2026 at 8:26 PM
A new preprint is being used to claim “persistent immune damage” after COVID. I’ve written a detailed scientific review explaining why that conclusion does NOT follow. Small cohort. Descriptive data. Big claims. This matters
open.substack.com/pu...
1/4
open.substack.com/pu...
1/4
Reposted by Marc Veldhoen
Now the US is bullying the EU to try and steal land, it is time for the EU to show its economic strength @vonderleyen. Match US tarifs on all goods and double it (20% now). Don´t stop, keep responding with doubling the tariffs. Ths US is no longer a friend, don´t treat it as one
January 17, 2026 at 5:51 PM
Now the US is bullying the EU to try and steal land, it is time for the EU to show its economic strength @vonderleyen. Match US tarifs on all goods and double it (20% now). Don´t stop, keep responding with doubling the tariffs. Ths US is no longer a friend, don´t treat it as one
Logical first response. The US . EU trade deal to be put on hold.
January 17, 2026 at 9:34 PM
Logical first response. The US . EU trade deal to be put on hold.
Two Rebulican Senetors are saying things against Trump, and they are correct.
Will they do anything to rein him in though?
Will they do anything to rein him in though?
January 17, 2026 at 9:26 PM
Two Rebulican Senetors are saying things against Trump, and they are correct.
Will they do anything to rein him in though?
Will they do anything to rein him in though?
Everytime you hear this weeks US report, the worse it is, what a terrible situation: the presidential troops acting with full immunity, not the perpertaror of a shoorting but the victim´s wife investigated, the wish to cancel the elections, the tuggish behaviour to get the Nobel Peace medal....
Saturday call for my "American Week", which I'm delighted to say more than 220,000 people have now watched or heard on-demand since yesterday. You can find it here:
📺: www.youtube.com/watch?v=WuKc...
🎧: audioboom.com/posts/883595...
📺: www.youtube.com/watch?v=WuKc...
🎧: audioboom.com/posts/883595...
'Trump's mafia-style extortion' | Simon Marks' American Week
YouTube video by LBC
www.youtube.com
January 17, 2026 at 8:44 PM
Everytime you hear this weeks US report, the worse it is, what a terrible situation: the presidential troops acting with full immunity, not the perpertaror of a shoorting but the victim´s wife investigated, the wish to cancel the elections, the tuggish behaviour to get the Nobel Peace medal....
"We don´t want Russia as neighbours"
🤦♂️
🤦♂️
January 17, 2026 at 8:40 PM
"We don´t want Russia as neighbours"
🤦♂️
🤦♂️
A new preprint is being used to claim “persistent immune damage” after COVID. I’ve written a detailed scientific review explaining why that conclusion does NOT follow. Small cohort. Descriptive data. Big claims. This matters
open.substack.com/pu...
1/4
open.substack.com/pu...
1/4
Persistent Immune Dysregulation in Long COVID? A new pre-print
The preprint “Persistent Immune Dysregulation during Long COVID is Manifested in Antibodies Targeting Envelope and Nucleocapsid Proteins” by Rehman and colleagues (2025) proposes that individuals with Post-Acute Sequelae of SARS-CoV-2 infection (PASC or Long COVID) exhibit long-lasting alterations in humoral and cellular immunity characterised by elevated IgG against SARS-CoV-2 Envelope (E) and Nucleocapsid (N) proteins, skewed immune cell profiles, and an inflammatory cytokine milieu persisting up to six months post-infection.
open.substack.com
January 17, 2026 at 8:26 PM
A new preprint is being used to claim “persistent immune damage” after COVID. I’ve written a detailed scientific review explaining why that conclusion does NOT follow. Small cohort. Descriptive data. Big claims. This matters
open.substack.com/pu...
1/4
open.substack.com/pu...
1/4
Reposted by Marc Veldhoen
My breaking news report for LBC on Donald Trump‘s decision to hit the UK, Denmark and their allies with punitive tariffs over Greenland.
🎧: audioboom.com/posts/883617...
🎧: audioboom.com/posts/883617...
Simon Marks Reporting / January 17, 2026 - AS IT BROKE: Trump hits UK, Denmark and allies with tariffs over Greenland
Simon's breaking news update for LBC, with Vanessa Feltz.
audioboom.com
January 17, 2026 at 5:19 PM
My breaking news report for LBC on Donald Trump‘s decision to hit the UK, Denmark and their allies with punitive tariffs over Greenland.
🎧: audioboom.com/posts/883617...
🎧: audioboom.com/posts/883617...
Now the US is bullying the EU to try and steal land, it is time for the EU to show its economic strength @vonderleyen. Match US tarifs on all goods and double it (20% now). Don´t stop, keep responding with doubling the tariffs. Ths US is no longer a friend, don´t treat it as one
January 17, 2026 at 5:51 PM
Now the US is bullying the EU to try and steal land, it is time for the EU to show its economic strength @vonderleyen. Match US tarifs on all goods and double it (20% now). Don´t stop, keep responding with doubling the tariffs. Ths US is no longer a friend, don´t treat it as one
Reposted by Marc Veldhoen
Because of agents of disinformation this needs to be investigated again. Funding and time wasted. A meta-analysis.
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
January 17, 2026 at 9:45 AM
Because of agents of disinformation this needs to be investigated again. Funding and time wasted. A meta-analysis.
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
New Substack: the myth that SARS-CoV-2 causes “premature ageing” of T cells.
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
The myth of SARS-CoV-2-induced premature T cell ageing
A critical look at the evidence
open.substack.com
January 17, 2026 at 2:13 PM
New Substack: the myth that SARS-CoV-2 causes “premature ageing” of T cells.
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
I break down basic T-cell biology, telomeres, why acute-phase studies mislead — and what longitudinal data actually show.
open.substack.com/pu...
1/2
Reposted by Marc Veldhoen
My "American Week" for @tomswarbrick.bsky.social's programme on the UK's @lbc.co.uk.
This week: Trump threatens to seize Greenland, gives ICE licence to kill, suggests there's no need for midterms and purloins a Nobel Peace Prize.
🎧: audioboom.com/posts/883595...
This week: Trump threatens to seize Greenland, gives ICE licence to kill, suggests there's no need for midterms and purloins a Nobel Peace Prize.
🎧: audioboom.com/posts/883595...
January 16, 2026 - "American Week": Trump threatens Greenland, and gives ICE licence to kill
Simon's weekly chronicle of events in the United States for Tom Swarbrick's drivetime programme on the UK's LBC. Listen live every Friday at 5:50pm, or find it here on-demand afterwards.
audioboom.com
January 16, 2026 at 8:36 PM
My "American Week" for @tomswarbrick.bsky.social's programme on the UK's @lbc.co.uk.
This week: Trump threatens to seize Greenland, gives ICE licence to kill, suggests there's no need for midterms and purloins a Nobel Peace Prize.
🎧: audioboom.com/posts/883595...
This week: Trump threatens to seize Greenland, gives ICE licence to kill, suggests there's no need for midterms and purloins a Nobel Peace Prize.
🎧: audioboom.com/posts/883595...
It cannot be claimed it was only Trump, or RFK Jr. All these politicians are trying to undermine reality. They do it the only way possible: by lying.
Why? To undermine reality, the truth that people experience. Then they can undermine it with "their thuth".
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Why? To undermine reality, the truth that people experience. Then they can undermine it with "their thuth".
1/2
January 17, 2026 at 11:27 AM
It cannot be claimed it was only Trump, or RFK Jr. All these politicians are trying to undermine reality. They do it the only way possible: by lying.
Why? To undermine reality, the truth that people experience. Then they can undermine it with "their thuth".
1/2
Why? To undermine reality, the truth that people experience. Then they can undermine it with "their thuth".
1/2
Reposted by Marc Veldhoen
Framing everyone as not having “Long COVID yet” is not science, it’s fear marketing. Risk is heterogeneous, evidence for inevitability is absent, and most people have no lasting issues. Public health needs precision, not deterministic claims that collapse uncertainty into doom.
January 17, 2026 at 9:56 AM
Framing everyone as not having “Long COVID yet” is not science, it’s fear marketing. Risk is heterogeneous, evidence for inevitability is absent, and most people have no lasting issues. Public health needs precision, not deterministic claims that collapse uncertainty into doom.
Reposted by Marc Veldhoen
The paper “COVID-19 is ‘Airborne AIDS’” is activism, not science. It uses fear-laden imagery to provoke emotion. No peer-reviewed data support a functional parallel between HIV’s chronic immune destruction and SARS-CoV-2 acute infection.
open.substack.com/pu...
1/5
open.substack.com/pu...
1/5
The abuse of science: the anti-science movement using cherry-picking to pretend SARS-CoV-2 has similar effects to HIV
How the "World Health Network" and all associated have lost even the last bit of credibility
open.substack.com
October 19, 2025 at 10:19 AM
The paper “COVID-19 is ‘Airborne AIDS’” is activism, not science. It uses fear-laden imagery to provoke emotion. No peer-reviewed data support a functional parallel between HIV’s chronic immune destruction and SARS-CoV-2 acute infection.
open.substack.com/pu...
1/5
open.substack.com/pu...
1/5
Reposted by Marc Veldhoen
Post-COVID-19 immune competence
A short reference for those facing arguments of immune damage, exhaustion, lymphopenia or immunodeficiency.
open.substack.com/pu...
A short reference for those facing arguments of immune damage, exhaustion, lymphopenia or immunodeficiency.
open.substack.com/pu...
October 20, 2025 at 12:53 PM
Post-COVID-19 immune competence
A short reference for those facing arguments of immune damage, exhaustion, lymphopenia or immunodeficiency.
open.substack.com/pu...
A short reference for those facing arguments of immune damage, exhaustion, lymphopenia or immunodeficiency.
open.substack.com/pu...
Reposted by Marc Veldhoen
Rates of infection with other pathogens after a positive COVID-19 test versus a negative test in US veterans (11/021, to 12/2023): a retrospective cohort study
No SC2 does not "damage your immune system. Some people are more susceptible to infection.
www.thelancet.com/jo...
1/7
No SC2 does not "damage your immune system. Some people are more susceptible to infection.
www.thelancet.com/jo...
1/7
Rates of infection with other pathogens after a positive COVID-19 test versus a negative test in US veterans (November, 2021, to December, 2023): a retrospective cohort study
Our results suggest that a positive test for COVID-19 (vs a negative test) was associated
with increased rates of diagnosis of various infections in the 12 months following
an acute SARS-CoV-2 infection. The putative long-term effects of COVID-19 on the immune
system and the propensity for infection with other pathogens should be further evaluated
in future studies.
www.thelancet.com
July 24, 2025 at 4:57 PM
Rates of infection with other pathogens after a positive COVID-19 test versus a negative test in US veterans (11/021, to 12/2023): a retrospective cohort study
No SC2 does not "damage your immune system. Some people are more susceptible to infection.
www.thelancet.com/jo...
1/7
No SC2 does not "damage your immune system. Some people are more susceptible to infection.
www.thelancet.com/jo...
1/7
Reposted by Marc Veldhoen
Long-term neutralization capacity of vaccine and breakthrough infection induced SARS-CoV-2 specific antibodies against omicron subvariants BA.2, XBB.1.5, and JN.1
Boosters and infectons induce high level neutralising antibodies against subvariants
www.sciencedirect.co...
1/10
Boosters and infectons induce high level neutralising antibodies against subvariants
www.sciencedirect.co...
1/10
Long-term neutralization capacity of vaccine and breakthrough infection induced SARS-CoV-2 specific antibodies against omicron subvariants BA.2, XBB.1.5, and JN.1
The long-term effectiveness of COVID-19 vaccines remains a critical area of study, especially with the emergence of new SARS-CoV-2 subvariants. In thi…
www.sciencedirect.com
October 30, 2025 at 1:51 PM
Long-term neutralization capacity of vaccine and breakthrough infection induced SARS-CoV-2 specific antibodies against omicron subvariants BA.2, XBB.1.5, and JN.1
Boosters and infectons induce high level neutralising antibodies against subvariants
www.sciencedirect.co...
1/10
Boosters and infectons induce high level neutralising antibodies against subvariants
www.sciencedirect.co...
1/10
Reposted by Marc Veldhoen
Persistent Attenuation of Lymphocyte Subsets After Mass SARS-CoV-2 Infection
A paper review.
I will make this formate more the focus in 2026. For requests of specific immunology papers or concepts, please put in a request. I will limit this to 1-2/week
A paper review.
I will make this formate more the focus in 2026. For requests of specific immunology papers or concepts, please put in a request. I will limit this to 1-2/week
Persistent Attenuation of Lymphocyte Subsets After Mass SARS-CoV-2 Infection
A paper review
marcveldhoen.substack.com
December 6, 2025 at 4:16 PM
Persistent Attenuation of Lymphocyte Subsets After Mass SARS-CoV-2 Infection
A paper review.
I will make this formate more the focus in 2026. For requests of specific immunology papers or concepts, please put in a request. I will limit this to 1-2/week
A paper review.
I will make this formate more the focus in 2026. For requests of specific immunology papers or concepts, please put in a request. I will limit this to 1-2/week
Framing everyone as not having “Long COVID yet” is not science, it’s fear marketing. Risk is heterogeneous, evidence for inevitability is absent, and most people have no lasting issues. Public health needs precision, not deterministic claims that collapse uncertainty into doom.
January 17, 2026 at 9:56 AM
Framing everyone as not having “Long COVID yet” is not science, it’s fear marketing. Risk is heterogeneous, evidence for inevitability is absent, and most people have no lasting issues. Public health needs precision, not deterministic claims that collapse uncertainty into doom.
Reposted by Marc Veldhoen
Vaccination against whooping cough, RSV and flu during pregnancy saves babies lives, but expectant parents are sometimes unsure.
How do I know it's safe? Will it protect my baby?
To answer these questions, we've created www.vaccinesinpregnancy.org
#ObGynSky #MedSky #ImmunoSky
1/
How do I know it's safe? Will it protect my baby?
To answer these questions, we've created www.vaccinesinpregnancy.org
#ObGynSky #MedSky #ImmunoSky
1/
Vaccines in Pregnancy, UK | Learn More About Vaccination Today
Comprehensive guide to vaccines during pregnancy in the UK, including timing and locations for vaccination. Essential information for expectant parents and healthcare providers.
www.vaccinesinpregnancy.org
January 16, 2026 at 10:02 AM
Vaccination against whooping cough, RSV and flu during pregnancy saves babies lives, but expectant parents are sometimes unsure.
How do I know it's safe? Will it protect my baby?
To answer these questions, we've created www.vaccinesinpregnancy.org
#ObGynSky #MedSky #ImmunoSky
1/
How do I know it's safe? Will it protect my baby?
To answer these questions, we've created www.vaccinesinpregnancy.org
#ObGynSky #MedSky #ImmunoSky
1/
Because of agents of disinformation this needs to be investigated again. Funding and time wasted. A meta-analysis.
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
January 17, 2026 at 9:45 AM
Because of agents of disinformation this needs to be investigated again. Funding and time wasted. A meta-analysis.
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
Prenatal paracetamol exposure and child neurodevelopment: a systematic review and meta-analysis
www.thelancet.com/jo...
1/2
Reposted by Marc Veldhoen
The [any] vaccine has an effect on herd immunity.
The concept of herd immunity is often presented as complicated, almost mystical, but its political use is anything but subtle. It sits at the very foundation of modern infectious disease control.
The concept of herd immunity is often presented as complicated, almost mystical, but its political use is anything but subtle. It sits at the very foundation of modern infectious disease control.
The [any] vaccine has an effect on herd immunity.
The concept of herd or group immunity is difficult
marcveldhoen.substack.com
January 4, 2026 at 7:01 PM
The [any] vaccine has an effect on herd immunity.
The concept of herd immunity is often presented as complicated, almost mystical, but its political use is anything but subtle. It sits at the very foundation of modern infectious disease control.
The concept of herd immunity is often presented as complicated, almost mystical, but its political use is anything but subtle. It sits at the very foundation of modern infectious disease control.
When you put just a few days together, recall the context, show the reality, show the footage..... and it is still not clear?
Extremely worrying and dangerous for all the world.
Extremely worrying and dangerous for all the world.
Jon on ICE's Killing of Renee Good and Trump's Model of Compliance for Protesters | The Daily Show
Jon Stewart digs into Trump announcing himself as Venezuela's acting president via Wikipedia, dividing Venezuela amongst cooperating oil companies, making a game-time decision to involve himself in Iran, and setting his sights on conquering Greenland so Russia can’t have it. Plus, Trump’s rules for
youtu.be
January 17, 2026 at 9:31 AM
When you put just a few days together, recall the context, show the reality, show the footage..... and it is still not clear?
Extremely worrying and dangerous for all the world.
Extremely worrying and dangerous for all the world.