One concept worth understanding in evidence-based work is the Woozle Effect.

It occurs when a claim gains the appearance of strong evidential support through repetition and citation, even though the original research did not clearly establish it.

- A preliminary or limited finding is published.
- Later summaries describe it with slightly more certainty.
- Secondary sources cite those summaries rather than the primary paper.
- Caveats, exclusions and uncertainty gradually disappear.
- Repetition creates familiarity.
- Familiarity is mistaken for reliability.
- The proposition becomes treated as established knowledge.

Eventually, the claim can feel settled simply because it has circulated widely enough.

The Woozle Effect is usually driven less by dishonesty than by repetition, assumption and uncritical citation. It often reflects ordinary human tendencies: confirmation bias, inherited beliefs, deference to consensus and failure to revisit primary sources.

The result is that non-facts can become common sense. In any field that relies on research, policy or expert opinion, that carries obvious risk.

The Woozle Effect is not merely about misinformation. It is about how intelligent people, acting in good faith, inherit certainty they did not build.

That is why disciplined analysis often begins with a deceptively simple question:

What did the original evidence actually show?

Repetition can amplify a claim but it cannot validate one.| 23 commentaires sur LinkedIn

Ils sont trois cents à s’être mobilisés.


À l’occasion de la semaine de la vaccination – du 27 avril au 3 mai 2026 –, et à l’initiative de l’Institut Pasteur, des personnalités issues de la recherche scientifique, de la médecine, de la culture, des médias et de la politique – dont de nombreux anciens ministres de la Santé – ont appelé à un « sursaut collectif face à la désinformation et aux attaques contre la science et la rationalité ».

Les idéologies “antivax” et les remous géopolitiques creusent les inégalités vaccinales à l’échelle mondiale et hypothèquent l’avenir de la recherche. Au centre des inquiétudes, les États-Unis. Superpuissance financière, politique et scientifique, le pays est devenu le maillon faible de la vaccination.

« L’arrivée au ministère de la Santé de Robert Kennedy Jr, un “antivax” qui accuse la vaccination de tous les maux, provoque une baisse de la couverture vaccinale dans le pays. Et cela fait extrêmement peur », estime le Dr Robert SEBBAG, médecin attaché dans le service des maladies infectieuses de l’hôpital Pitié-Salpêtrière, à Paris, et président de l’ONG ACTION CONTRE LA FAIM.

Depuis l’installation à la Maison Blanche de la nouvelle administration Trump, les fausses informations relatives à la vaccination passent désormais par les canaux officiels. En novembre 2025, la principale agence sanitaire des États-Unis, les CDC (Centres de prévention et de lutte contre les maladies) relayaient une indéboulonnable fausse théorie sur les liens supposés entre les vaccins et l’autisme.

https://l.lepoint.fr/Py4
Par Héloïse Rambert

"Let me start with a confession. I used to be the parent who gripped my child’s hand too tightly at the clinic and felt my stomach drop. This was not because of the needle but because of the stories. The whispers and warnings, the doubts about something unnatural entering a healthy body through a vaccine, unsettled me far more than the procedure itself.

I have learned that fear has a geography. In Nigeria, it is vast and varied. It exists in Makoko’s alleys, where a mother cannot miss a day of fish trading for the clinic. It lives in dusty Borno, where a young father’s trust in government is broken after seeing more violence than medicine. It is even found in air-conditioned Lagos living rooms, where educated couples debate the ethics of the HPV vaccine over snacks and drinks.

This is the landscape of World Immunisation Week, which is observed this year from April 24 to April 30. The global theme is “For every generation, vaccines work”. That phrase is not a slogan you paste on a banner and forget. It is a quiet declaration that the same needle that protected your grandfather from smallpox protects your newborn from rotavirus. It serves as a reminder that immunity does not go out of style or retire. It passes from arm to arm, from decade to decade, like a torch that must never drop.

Now, let me give you a figure that should unsettle you. The World Health Organisation estimates that one in five Nigerian children still misses out on routine immunisation. That is not a statistic. That is a child in Kaduna who will never see his fifth birthday because of measles. That is a baby girl in Ebonyi who contracts polio just as the country celebrates being polio‑free."

Right wing influencers aligned with MAHA, like Jeffrey Tucker at the Brownstone Institute, are calling for the elimination of the FDA. It’s all recycled “health freedom” revisionist history and ahistorical nonsense long peddled by libertarians like Zach Weissmueller, Nick Gillespie, and Ronald Bailey at Reason. The real goal is to eliminate the FDA, thereby giving quacks their long-desired freedom from pesky laws and regulation protecting the public. https://lnkd.in/euQ_U3NM

Two rigorous new studies reach the same conclusion: delaying the hepatitis B birth dose means hundreds more infant infections, more liver cancer, more deaths, and millions of dollars in added costs. The evidence for the birth dose has always been strong. These studies make it even stronger. https://lnkd.in/gp4EszHb

More than 30 million doses. Over 1 million zero-dose children reached. In collaboration with the International Rescue Committee and with funding from Gavi, partners are helping deliver routine and catch-up vaccination in some of the world’s most fragile and conflict-affected settings. This milestone shows what’s possible when immunisation delivery models are designed for crisis contexts. Read more: https://bit.ly/4cJrMwx #WorldImmunizationWeek    

Vaccines have long been considered by experts to be among the most studied medical interventions, and on the whole, Americans are still broadly supportive of them.

But during President Donald Trump’s second term, the agency that makes recommendations about vaccines—the U.S. Centers for Disease Control and Prevention (CDC)—has, without new scientific evidence, cast fresh doubt on their safety and resurfaced the disproven link between vaccines and autism.

I’m really grateful to share that I passed my DPhil viva at the University of Oxford 🎓

My thesis explored how changes to immunisation programmes are understood and experienced across different global health contexts - moving beyond vaccine acceptance and hesitancy, to how individuals navigate uncertainty, trust, and change amidst evolving health systems and policy.

A huge thank you to my examiners, Tracey Chantler and Sally Frampton FRHistS, for an incredibly enjoyable viva, as well as Prof. Patricia Kingori, Trish Greenhalgh, and Simon Drysdale, who have assessed the work at the various stages of the DPhil.

A special thank you to my supervisors: Sir Andrew Pollard, Samantha Vanderslott, Dr Sam M., and Katrina Pollock for support throughout.

And to the many collaborators, mentors, colleagues, friends, and participants who made this work possible - thank you. There are too many to name, but this work is as much yours as it is mine!

And somehow, it feels especially meaningful that this comes at the end of World Immunization Week! 🎉

University of Oxford | Oxford University Department of Paediatrics | Reuben College, University of Oxford | Oxford Vaccine Group | 80 comments on LinkedIn

Anti-vaccine activists are not looking for informed consent. In the term used by David Gorski, they want their followers to refuse vaccines because they feed them misinformation - they look for misinformed refusal.
[Kennedy] "... told everyone that the “hepatitis B vaccine was not safety tested. It had a four-day test with no placebo. We don’t know what the risk profile is. Parents are allowed to ask that question.”

Do you see the problem?

Parents listening to him are actually not being allowed informed consent because they are being scared and guided with misinformation!

The hepatitis B vaccine clinical trial lasted for over six months and did include a placebo!"

Weekendavisen fortsætter sin kampagne – fokus flyttes nu fra forskning til personangreb

Weekendavisen fortsætter sin serie om vores forskning – nu med et tydeligt skifte fra faglig kritik til framing af personer, relationer og motiver - måske fordi det ikke lykkedes at påvise faglige fejl. Men fremgangsmåden er den samme: WA benytter sig af få håndplukkede kilder, som først og fremmest er kendt for deres meninger, ikke argumenter, og i strid med de presseetiske retningslinjer, gives vi ikke reel mulighed for at komme til orde.

Det sker på trods af, at vi på 11. måned har en verserende klage i Pressenævnet. Nu sender vi en ny. Vi accepterer ikke kampagnejournalistik, der i sidste ende bidrager til mindre sikre vacciner, øget mistillid og udskamning af vaccineskadede.

WA sendte seks omfattende anklagepunkter mandag eftermiddag med svarfrist onsdag kl. 9. Vi påpegede, at én arbejdsdag var en meget kort frist. Det blev afvist. Vi nåede derfor kun at gennemgå ét punkt i dybden – det om GAVI – og kunne klart dokumentere, at fremstillingen dér er fejlagtig og ensidig.

Jeg deler her (se billede) den mail, vi sendte, med:
• en samlet kommentar
• et konkret, dokumenteret svar på GAVI-punktet

Men vores input var åbenlyst ikke ønsket. For i WA artiklen er der:
1) Forkert gengivelse: WA skriver, at jeg ikke ønsker, at de citerer mig. Det er forkert. Vi bad om fuld gengivelse.
2) Manglende sammenhæng mellem angreb og svar: I strid med presseetiske retningslinjer - hvor angreb og svar bør bringes i sammenhæng og på samme måde - har WA ikke trykt vores svar sammen med artiklen.
3) Selektiv brug af svar: Kun dele af vores GAVI-svar gengives. Linket til “hele svaret” fører ikke til dette svar, men til en anden tekst. Vores centrale indsigelser er udeladt. WA viderebringer dermed kritik, som vi allerede har tilbagevist.
4) Manglende kontekst: Det fremgår ikke, at vi havde én arbejdsdag til at svare på seks komplekse anklager, og derfor kun kunne nå at gennemgå ét punkt.

I bedste fald er det mangelfuldt journalistisk håndværk. I værste fald en bevidst vinkling. Når svar ikke får plads, er det ikke journalistik. Så er det en fortælling med et på forhånd valgt resultat.

Det mest problematiske er måske dette: Når forsøg på at forstå og håndtere mulige vaccinebivirkninger fremstilles som “antivax”, skubbes en sårbar patientgruppe yderligere ud i marginalen.

Jeg er ikke vaccinemodstander. Jeg er forsker i vacciners samlede sundhedseffekter. Faglig dialog – også med uenige – er en forudsætning for videnskab. At fremstille det som noget andet er misvisende.

Offentligheden kan med rette spørge, hvem der står bag denne type framing. Konsekvensen er færre vaccineforskere, mere selvcensur og mindre viden. Det skader både vaccinesikkerheden, vaccinetilliden, og borgerne. Cui bono? | 35 comments on LinkedIn

📍 Polio | World Immunization Week
 
Wild poliovirus type 1 (WPV1) remains endemic in Pakistan and Afghanistan—the only two countries where endemic transmission has not been sustainably interrupted. This persistence reflects a critical gap in global health equity and poses an ongoing risk to health security worldwide.
 
Polio is highly contagious and entirely vaccine-preventable, yet gaps in access mean transmission continues. While most infections are asymptomatic or mild, the virus can spread undetected—yet about 1 in 200 infections leads to irreversible paralysis, primarily affecting young children. There is no cure.
 
As long as WPV1 circulates anywhere, no country is fully protected from the risk of importation. Recent detections of poliovirus in environmental samples in high-income countries underscore this reality.
 
At the Canadian Association for Global Health (CAGH), we emphasize that global eradication of polio is within reach—but the final steps require sustained investment, equity-driven strategies, and global solidarity to reach every child, everywhere.
 
Read the full story: https://lnkd.in/etBbVQEE

#Polio #GlobalHealth #HealthEquity #VaccinesWork #PolioEradication #CAGH

The hantavirus conspiracy theories are coming! Peter McCullough is already pushing the use of Ivermectin for Hantavirus infections. https://lnkd.in/gyhfHcYQ

"In February 2025, Robert F Kennedy Jr began his tenure as secretary of the Department of Health and Human Services (HHS) with an unusual message for the federal department responsible for protecting public health.

America’s greatest challenge, he said, was not just chronic disease but a “spiritual malaise”, a kind of soul-sickness derived from America’s moral decline.

“Spiritual and physical maladies thrive on one another,” Kennedy told HHS employees in his first address. The solution, he said, “must begin with a spiritual question”, of personal responsibility and inward vigilance against the dark forces that would keep Americans “sedated” and “compliant”.

Weeks later, the White House moved to cut 20,500 jobs across the very agency tasked with protecting public health.

This March, as the US faced its worst measles resurgence in 34 years – one he has largely ignored – Kennedy again warned the nation of the same nebulous threat.

This time, he took a more militant tone. “Malevolent forces”, he told an audience of doctors-in-training, must be met with “spiritual warfare”, waged through the “sacred ritual” of eating dinner together as a family.

Now over a year into his tenure, Kennedy champions personal discipline while casting institutional science as a dark force in a cosmic struggle against the light. He has promoted pseudoscientific or unproven remedies, including vitamin A for measles, peptides for longevity and the nutritional benefits of raw milk, while sowing doubt about the safety and efficacy of vaccines.

Because of his granola aura as a former environmental advocate, Kennedy’s invocation of the “spiritual” can initially sound benign – more hippy than doctrinaire.

Yet his repeated references to spiritual forces are more than run-of-the-mill wellness vernacular. They are a signal that the Christian nationalist movement that helped propel Trump into office is now reshaping the public health agency from the inside.

The effect is corrosive, eroding the nation’s shared epistemological reality – like a worm working its way through brain tissue."
https://lnkd.in/dGzK6pq8

Recent research highlights the potential of "freedom framing" in public health messaging to address vaccine hesitancy. Survey data indicate that individuals with higher vaccine concerns are more receptive to messages emphasizing personal autonomy, compared to mandates or appeals to social responsibility. This approach resulted in a six percentage point increase in willingness among hesitant respondents. These findings suggest that tailoring communication strategies to align with individual values may be more effective than universal messaging. Further behavioral studies are planned to assess the impact of this framing on actual vaccination rates in real-world settings.

Pregnant women’s mental imagery, what they see when thinking about vaccines, can meaningfully shape their decisions.

Our latest research shows positive imagery predicts earlier vaccination, while negative imagery aligns with hesitancy. A reminder that vaccine communication isn’t just about facts; it’s also about emotions and imagination.

Proud of the interdisciplinary team behind this work. https://lnkd.in/g_4tnEKG

I had my Digital Health class do informal content analyses of the top 10 most viewed TikTok videos on a health topic of their choice. Students (N=100 undergrads) are mostly allied health science majors---our future healthcare professionals! I wanted them to understand what type of health content the algorithm rewards and the importance of science communication. What they found was fascinating and occasionally horrifying. ⬇️ ⬇️

Obesity – the top videos were of two types: healthcare professionals debunking misinformation (yay!) and fat phobic influencers (UGH!). It was a shame to see the algo promoting such mixed messages.

Diabetes – top videos were dominated by healthcare professionals and influencers and contained mixed messages about diet and causes of diabetes. Diabetes content had more misinformation than other topics.

Breast cancer – the misinformation on this subject was bad. One top video was of a patient with breast cancer discouraging people from traditional therapies (e.g., chemo, radiation) and another was of an influencer promoting breast cream that "prevents" cancer. Thankfully, half of the top videos were by healthcare professionals providing evidence-based education about prevention and treatment.

Skin cancer – this was the topic in which the experts were leading the narrative. Nearly all top videos were docs showing folks what different types of skin cancer look like and how to prevent and treat them. Gross pics get views! Go derms! 💚

Depression and ADHD: patients dominated the top videos. Mental health professionals rarely appeared. Patients did a great job of debunking myths and destigmatizing these conditions. Go patients! ❤️

Key issues:

❓ Creator confusion: Students sometimes confused who the creator was because the person in the video was not always the person who posted it. Influencers often used expert and patient voices to elevate and legitimize their content.

💲 HCPs were the most likely to be selling stuff:  Promotional content was almost always by healthcare professionals and they were typically peddling supplements and peptides. Students who noticed the creator was selling something downgraded their credibility, but many students did not notice that the creator was selling something.

❌ Evidence for claims was rare: Healthcare providers almost never provided evidence or links to evidence for their health claims. This made it difficult for students to assess the credibility of claims made.

🤡 Who dis? Some top videos were from accounts with cryptic bios and cartoon profile pics that made it impossible to know the identity of the creator.

🏥 Where’s public health? Of many hundreds of top videos, only ONE was from a public health org (WHO). 😮 | 22 comments on LinkedIn

This study provides the first cost-effectiveness analysis of chikungunya vaccines in an endemic middle-income setting. Both the live-attenuated and recombinant vaccines were cost-effective compared with no vaccination, with the live-attenuated vaccine yielding greater NMB under base-case assumptions. However, given ongoing postmarketing safety evaluations of the live-attenuated product, policy decisions should weigh comparative effectiveness alongside emerging safety data and population-specific risk profiles. Overall, our findings indicate that chikungunya vaccination represents a potentially scalable cost-effective strategy to reduce the long-term health and economic burden of disease in endemic settings.
https://lnkd.in/dcZtd7xg

When you don’t understand anything…
EVERYTHING is a conspiracy. | 14 comments on LinkedIn

À venir en mai ! 📆

Nous espérons que vous avez passé un agréable weekend du 1er mai ! Avec les congés et ponts, notre agenda est un peu moins chargé (on vous laisse souffler !) mais nos membres pourront profiter de ces activités :

- 22 mai : Formation sur les bases immunologiques avec le Professeur Jean Daniel Lelièvre (Vaccine Research Institute)

- 26 mai : Apéro débat sur le thème de "Décliner ses sujets" (plus d'informations prochainement !)

- 26 mai : Visite à Paris à l'Institut de Myologie

Joyeux mois de mai à toutes & tous et au plaisir de vous croiser lors de ces événements !

Peter Marks (formerly of the FDA) met with individuals reporting vaccine-related injuries in 2022, where they shared personal impact statements. The meeting was intended to raise concerns and push for change, but participants saw little follow-up afterward.

Steve Wenger shared that within a week of receiving his vaccine, he couldn’t walk safely. After 98 days in the hospital, he was diagnosed with CIDP, a serious neurological condition.

On Wednesday, Ron Johnson will hold a hearing titled “Unmasked: How Biden Health Officials Purposely Turned a Blind Eye Toward COVID-19 Vaccine Safety Signals.”

The Senate Permanent Subcommittee on Investigations is also expected to release a large volume of records examining whether officials were aware of limitations in a key vaccine safety monitoring system. Stay tuned for streaming details.

💉 Dernier jour de la Semaine de la vaccination
Dans le cadre de la Semaine européenne de la vaccination, la SFI Société Française d'Immunologie a partagé ces derniers jours plusieurs éclairages sur les enjeux de la vaccination et son impact en santé publique.
👉 Si cette semaine touche à sa fin, elle ne marque pas celle de notre mobilisation : la vaccination reste une priorité, bien au-delà de cette semaine.
👉 Pour conclure, place à un focus essentiel : la protection des populations les plus vulnérables.

🚨 Le paradoxe vaccinal : ceux qui en ont le plus besoin sont souvent ceux qui y répondent le moins bien.
À l'horizon 2050, le vieillissement de la population s'accompagnera inévitablement d'une hausse des maladies chroniques et de la fragilité. Face aux infections, les seniors et les personnes immunodéprimées sont en première ligne.

Comment adapter nos stratégies face aux défis posés par un système immunitaire affaibli ? Voici 4 grands axes :

📉 1. Le défi de l'immunosénescence: Avec l'âge, notre système immunitaire décline et s'accompagne d'une inflammation chronique ("inflammaging"). Conséquence : la réponse aux vaccins est moins intense. Pourtant, le bénéfice clinique reste majeur. Même imparfaitement efficace, le vaccin antigrippal chez les seniors réduit drastiquement les hospitalisations, la mortalité (ils représentent 90 % des décès liés à la grippe) et protège même contre les événements cardiovasculaires !

🔬 2. L'innovation pour des vaccins "sur-mesure": La vaccination des seniors n'est pas un simple "copier-coller" de l'adulte jeune. Pour compenser la baisse d'immunité, la science s'adapte : vaccins à haute dose, adjuvants ciblés (MF59, AS01) pour booster la présentation antigénique, ou encore plateformes ARNm. L'objectif ? Stimuler des réponses immunitaires robustes, notamment cellulaires (lymphocytes T).

🛡️ 3. La stratégie de bouclier pour les immunodéprimés: Pour ces patients au risque infectieux décuplé, l'efficacité vaccinale est souvent diminuée. La stratégie repose sur l'anticipation (vacciner avant une chimiothérapie ou une greffe) et l'intensification (schémas avec doses additionnelles). Et quand le vaccin ne suffit pas ou est contre-indiqué, la prophylaxie par immunoglobulines prend le relais.

🤝 4. L'immunité de groupe : la protection indirecte La protection des plus fragiles passe aussi par les autres ! Vacciner les enfants contre le pneumocoque ou la grippe a un impact direct sur l'incidence de ces infections chez les seniors. De la même manière, vacciner l'entourage ("cocooning") est vital pour les patients immunodéprimés qui ne peuvent pas recevoir certains vaccins vivants atténués.

La vaccination des populations vulnérables nécessite une approche spécifique et de précision. Elle s'inscrit dans une stratégie globale d'avenir : ne plus seulement ajouter des années à la vie, mais ajouter des années en bonne santé.
#Vaccination #Immunologie #Gériatrie #SantéPublique #Prévention #InnovationMédicale

On ne laissera pas le terrain aux complotistes, aux antivax. Ce qu'il se passe aux États-Unis est un sacré avertissement pour l'Europe.

Retour dans Ouest-France sur mon parrainage aux côtés du Dr Dr François Sarkozy et le lancement de l'Alliance « Immunisation et Prévention des Infections » à l'Assemblée nationale. Une alliance inédite réunissant les Académies de médecine et de pharmacie, des sociétés savantes, des associations de patients, des économistes.

Le constat est clair : 150 € par an et par personne consacrés à la prévention en France, contre 450 € en Allemagne. La prévention n'est pas une dépense, c'est un investissement sur l'avenir des Français.

Je porterai une proposition de loi reprenant les préconisations de la mission Molimard : observatoire de la désinformation en santé et cellule de riposte rapide.

Face aux marchands de doute, c'est un combat politique.

Je salue l'engagement des membres du comité stratégique : Pr Elisabeth Botelho-Nevers (infectiologie), Pr Olivier Guerin (gériatrie), Pr Hervé Haas (pédiatrie), Pr Antoine Flahault (épidémiologie), Pr Ariel Cohen (cardiologie), Pr Yvon LEBRANCHU (immunologie), Dr Pierre-Yves Chambrin (pharmacie), Catherine SIMONIN-BÉNAZET et Dr Jean-François Thébault (patients).

→ https://lnkd.in/eheeYuxV | 19 comments on LinkedIn