Zach Most, MD, MSc retweeted
My resignation letter from CDC.
Dear Dr. Houry,
I am writing to formally resign from my position as Director of the National Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention (CDC), effective August 28, 2025, close of business. I am happy to stay on for two weeks to provide transition, if requested.
This decision has not come easily, as I deeply value the work that the CDC does in safeguarding public health and am proud of my contributions to that critical mission. However, after much contemplation and reflection on recent developments and perspectives brought to light by Secretary Robert F. Kennedy Jr., I find that the views he and his staff have shared challenge my ability to continue in my current role at the agency and in the service of the health of the American people. Enough is enough.
While I hold immense respect for the institution and my colleagues, I believe that it is imperative to align my professional responsibilities to my system of ethics and my understanding of the science of infectious disease, immunology, and my promise to serve the American people. This step is necessary to ensure that I can contribute effectively in a capacity that allows me to remain true to my principles.
I am unable to serve in an environment that treats CDC as a tool to generate policies and materials that do not reflect scientific reality and are designed to hurt rather than to improve the public’s health. The recent change in the adult and children’s immunization schedule threaten the lives of the youngest Americans and pregnant people. The data analyses that supported this decision have never been shared with CDC despite my respectful requests to HHS and other leadership. This lack of meaningful engagement was further compounded by a “frequently asked questions” document written to support the Secretary’s directive that was circulated by HHS without input from CDC subject matter experts and that cited studies that did not support the conclusions that were attributed to these authors. Having worked in local and national public health for years, I have never experienced such radical non-transparency, nor have I seen such unskilled manipulation of data to achieve a political end rather than the good of the American people.
It is untenable to serve in an organization that is not afforded the opportunity to discuss decisions of scientific and public health importance released under the moniker of CDC. The lack of communication by HHS and other CDC political leadership that culminates in social media posts announcing major policy changes without prior notice demonstrate a disregard of normal communication channels and common sense. Having to retrofit analyses and policy actions to match inadequately thought-out announcements in poorly scripted videos or page long X posts should not be how organizations responsible for the health of people should function. Some examples include the announcement of the change in the COVID-19 recommendations for children and pregnant people, the firing of scientists from ACIP by X post and an op-ed rather than direct communication with these valuable experts, the announcement of new ACIP members by X before onboarding and vetting have completed, and the release of term of reference for an ACIP workgroup that ignored all feedback from career staff at CDC.
The recent term of reference for the COVID vaccine work group created by this ACIP puts people of dubious intent and more dubious scientific rigor in charge of recommending vaccine policy to a director hamstrung and sidelined by an authoritarian leader. Their desire to please a political base will result in death and disability of vulnerable children and adults. Their base should be the people they serve not a political voting bloc.
I have always been first to challenge scientific and public health dogma in my career and was excited by the opportunity to do so again. I was optimistic that there would be an opportunity to brief the Secretary about key topics such as measles, avian influenza, and the highly coordinated approach to the respiratory virus season. Such briefings would allow exchange of ideas and a shared path to support the vision of “Making America Healthy Again.” We are seven months into the new administration, and no CDC subject matter expert from my Center has ever briefed the Secretary. I am not sure who the Secretary is listening to, but it is quite certainly not to us. Unvetted and conflicted outside organizations seem to be the sources HHS use over the gold standard science of CDC and other reputable sources. At a hearing, Secretary Kennedy said that Americans should not take medical advice from him. To the contrary, an appropriately briefed and inquisitive Secretary should be a source of health information for the people he serves. As it stands now, I must agree with him, that he should not be considered a source of accurate information.
The intentional eroding of trust in low-risk vaccines favoring natural infection and unproven remedies will bring us to a pre-vaccine era where only the strong will survive and many if not all will suffer. I believe in nutrition and exercise. I believe in making our food supply healthier, and I also believe in using vaccines to prevent death and disability. Eugenics plays prominently in the rhetoric being generated and is derivative of a legacy that good medicine and science should continue to shun.
The recent shooting at CDC is not why I am resigning. My grandfather, who I am named after, stood up to fascist forces in Greece and lost his life doing so. I am resigning to make him and his legacy proud. I am resigning because of the cowardice of a leader that cannot admit that HIS and his minions’ words over decades created an environment where violence like this can occur. I reject his and his colleagues’ thoughts and prayers, and advise they direct those to people that they have not actively harmed.
For decades, I have been a trusted voice for the LGBTQ community when it comes to critical health topics. I must also cite the recklessness of the administration in their efforts to erase transgender populations, cease critical domestic and international HIV programming, and terminate key research to support equity as part of my decision.
Public health is not merely about the health of the individual, but it is about the health of the community, the nation, the world. The nation’s health security is at risk and is in the hands of people focusing on ideological self-interest.
I want to express my heartfelt gratitude for the opportunities for growth, learning, and collaboration that I have been afforded during my time at the CDC. It has been a privilege to work alongside such dedicated professionals who are committed to improving the health and well-being of communities across the nation even when under attack from within both physically and psychologically.
Thank you once again for the support and guidance I have received from you and previous CDC leadership throughout my tenure. I wish the CDC continued success in its vital mission and that HHS reverse its dangerous course to dismantle public health as a practice and as an institution. If they continue the current path, they risk our personal well-being and the security of the United States.
Sincerely,
Demetre C. Daskalakis MD MPH (he/his/him)
Zach Most, MD, MSc retweeted
BOTTOM LINE:
When “evidence” relies on phantom papers, misquotes, 48‑year‑old Soviet data, and math that doesn’t add up - while ignoring results from millions of kids - you’re not doing science; you’re spreading misinformation.
The IOM, CDC, FDA, WHO, and researchers from four countries have reviewed thimerosal repeatedly. Their conclusion is consistent:
No link to autism
No credible harm at vaccine‑level exposure
Vaccine policy must be driven by solid evidence, not paranoia or phantom studies.
Full breakdown with citations:
xitter.cf/jakescottMD/status/193…
It’s not easy to navigate the maelstrom of misinformation. Grateful to @megtirrell and @boulware_dr for cutting through it.
Slides prepared for ACIP this week by former CHD leader Lyn Redwood cited a 2008 Neurotoxicology study on thimerosal and “long-term brain harm.”
But the study doesn’t exist. The listed author says he never wrote it and his actual research found no such effect.
Debates should be grounded in evidence, not phantom citations.
Thimerosal has been thoroughly studied for decades. Here's what the evidence actually shows🧵👇
cnn.com/2025/06/24/health/cd…
Zach Most, MD, MSc retweeted
We cannot do the complex and serious work of protecting Americans from infectious diseases amid this chaos and confusion.
Our statement on April 1 HHS Job Cuts: idsociety.org/news--publicat…
Zach Most, MD, MSc retweeted
The removal of #HIV- and #LGBTQ-related resources from the websites of the @CDCgov and other health agencies is deeply concerning.
Access to this information is crucial for ID and HIV health care professionals.
Our full statement: bit.ly/3PYun9v
Zach Most, MD, MSc retweeted
Per @absteward's request, here are updated slides showing # new abx approved by 5 year periods, & table showing specific new Abx since 2009--green = meets unmet need; yellow = sorta maybe has some use; red = does not address unmet need. We continue to get new abx we don't need.
Zach Most, MD, MSc retweeted
🆕️⚡️ @jpidsociety
Retrospective Observational Assessment of the Impact of Cefepime Prophylaxis in Neutropenic Pediatric Patients With Acute Myelogenous Leukemia #IDXposts
academic.oup.com/jpids/advan…
Zach Most, MD, MSc retweeted
A great talk today by Dr. Mehgan Kidd at "Infectious Diseases and Geographical Medical Division Grand Rounds"
#IDtwitter #utsw #pedsid
Zach Most, MD, MSc retweeted
In addition to having the passion for treating infections, we love and appreciate art.
UTSW annual art display is on!
Our program director, Dr. Kahn is a talented photographer displaying one of his collections and one of our fellows, Dr. Rubbab with her acrylic art on canvas.
Zach Most, MD, MSc retweeted
Just facts!
# Not all of the positive urine cultures represent a UTI.
#IDtwitter
Zach Most, MD, MSc retweeted
FREE Mpox Vaccine Clinic‼️
Join us tomorrow at the Dallas Pride Festival @fairparkdallas to get vaccinated against Mpox. @dallasprideorg. Take action & protect yourself.
For more visit: bit.ly/41cAWcw
Zach Most, MD, MSc retweeted
Introducing our amazing Infectious disease family.
We all love to learn, teach, and take pictures.
Zach Most, MD, MSc retweeted
In children with COVID-19, preexisting comorbidities and residency in the Southern United States were positively associated with worse outcomes, whereas vaccination was negatively associated. @ZMostMD @SamehSalehMD @johnhannamd @IDInformaticsMD @robturer
publications.aap.org/hospita…
Zach Most, MD, MSc retweeted
#Viewpoint discusses increased rates in pediatric mortality by age and cause between 1999 and 2021. ja.ma/3nvKFMg
Zach Most, MD, MSc retweeted
Yet another one of those illustrations why (propensity score) matching might not do the job #EconTwitter
Zach Most, MD, MSc retweeted
Today, the AAP reaffirms our support for adolescents to receive comprehensive, evidence-based reproductive healthcare services, including abortion, within two new updated policy statements. 1/2
Zach Most, MD, MSc retweeted
Today’s Supreme Court decision to overturn Roe v. Wade means that the once Constitutionally protected right to access an abortion is no longer guaranteed nationwide. 1/3
Zach Most, MD, MSc retweeted
Lack of standard definitions of healthcare-associated respiratory viral infections (HARVI) make inter-hospital comparisons hard.
Authors experienced 0.98 HARVI per 1,000 patient days at one pediatric hospital
doi.org/10.1017/ice.2022.33
Zach Most, MD, MSc retweeted
TOGETHER randomized trial: 11% (79/741) of the fluvoxamine group needed hospital care, vs 16% (119/756) of the placebo group (probability of superiority of 99·8%). Mortality in the per-protocol analysis: 1 for fluvox, 12 for placebo. Encouraging results! doi.org/10.1016/S2214-109X(2…
Zach Most, MD, MSc retweeted
Day #9: How quickly can antibiotics turn blood cultures negative? Fast! The rate of pos blood cultures reduced by >50% just an hour after IV antibiotic Rx -- but many will still be positive, so getting cultures in septic pts still useful. doi.org/10.1093/ofid/ofz179































