The Centers for Disease Control and Prevention (CDC) needs to up its game when it comes to monitoring vaccine safety and communicating that information to health professionals and the public, according to a new consensus report from the National Academies of Sciences, Engineering and Medicine (NASEM).

NASEM also urged the CDC to better distinguish between the role of its Immunization Safety Office (ISO) in monitoring vaccine risks and the agency’s broader efforts to promote vaccination. The overlap “continues to raise public concerns about the objectivity of risk assessments,” NASEM said in a press release.

“CDC should protect ISO’s independence, keeping the office operationally and administratively insulated from units in CDC that carry out promotion or policymaking activities, such as promoting vaccination,” NASEM concluded.

Children’s Health Defense (CHD) Chief Scientific Officer Brian Hooker, who has been advocating for a more transparent and robust vaccine safety monitoring system for decades, told The Defender the report was “too little, too late,” and “doesn’t go nearly far enough.”

“It is notable,” Hooker said, “that the assessment was headed up by Dr. Kathleen Stratton, who was instrumental in NASEM’s denial of the vaccine-autism link in the early 2000s.” Leaked documents showed that Stratton coordinated with the CDC to deny any links between vaccines and autism.

Hooker said the new NASEM report “is a word salad joke and represents the best efforts of Stratton to continue to lie and hide about the gross failures of the CDC to protect the public from vaccine injury. “

The report, “Vaccine Risk Monitoring and Evaluation at the Centers for Disease Control and Prevention” (2025), reviews the performance of the CDC’s ISO during the COVID-19 pandemic. The office is responsible for studying vaccine risks when vaccines are administered to the public.

During the pandemic, the office was headed by Dr. Tom Shimabukuro, best known for authoring a key paper and participating in public messaging claiming the COVID-19 vaccines were safe and effective for pregnant women.

The ISO was tasked with detecting, investigating and reporting potential COVID-19 vaccine safety concerns. The CDC commissioned NASEM to comprehensively assess ISO’s epidemiologic and statistical methods for vaccine safety monitoring, and its public-facing communication strategies.

The committee concluded that the ISO operates a robust and thorough system of vaccine surveillance, but there remain gaps in consistency, timeliness, and clarity that could delay detection of rare adverse events or weaken public confidence in the agency. However, the “gaps” they identified were minor, experts told The Defender.

No mention of ISO’s delays in reporting myocarditis signal

During the pandemic, ISO used established systems for vaccine safety monitoring — including the Vaccine Adverse Event Reporting System (VAERS), the Vaccine Safety Datalink and the Clinical Immunization Safety Assessment network — together with V-safe and the COVID-19 Vaccine Pregnancy Registry, newer tools introduced during the pandemic.

These systems are designed to detect safety signals — indications that an adverse event may be linked to a vaccine — and to investigate those possible associations and help guide public health decisions. NASEM identified several problems that emerged in that process.

The different surveillance systems sometimes didn’t communicate effectively, making it harder to triangulate signals or compare findings across databases. The lack of a permanent national reporting infrastructure, geographical fragmentation and inconsistent standards “hinder comprehensive, long-term surveillance,” NASEM said.

Public transparency was lacking around “the criteria for elevating, deferring, or ceasing work on a specific signal.” The ISO identified some key signals late, or didn’t prioritize them for rapid review, either due to a lack of resources or a failure to have proper procedures in place, according to the NASEM committee.

Problems integrating safety signal data across systems and the failure to transparently prioritize which signals mattered meant that emerging public concerns, such as menstrual changes, “often outpaced analytic response,” the report said.

However, the committee also lauded ISO’s early identification of side effects, including  thrombosis with thrombocytopenia syndrome, myocarditis and Guillain-Barré syndrome in ways they said “allowed for timely clinical guidance, reduced preventable morbidity, and informed risk–benefit assessments for distinct populations.”

But those statements contradict the findings by others, including CHD, that the CDC knew of the myocarditis risk months before it informed the public.

“As reported in the Congressional Record, the ISO lied about the myocarditis risk for 6 months after the first reports were made to them,” Hooker said. NASEM did not mention that in the report.

During NASEM’s public presentation on the report today, The Defender submitted a question asking why the report didn’t address the ISO’s delay in reporting myocarditis to the public, but NASEM declined the question.

A truly independent board likely would have shut down the vaccination campaign in January 2021

NASEM raised concerns that CDC’s messaging to the public and health professionals sometimes lacked clarity about the magnitude of risk associated with COVID-19 vaccines or the agency’s rationale for recommending the vaccines.

The report also noted that ISO’s scientific publications and CDC communications so consistently included strong messages about vaccine benefits that it fueled public perception that the ISO was biased in favor of the vaccines.

Dr. Peter McCullough, a cardiologist who sounded the alarm about vaccine-induced myocarditis early in the pandemic, said public comments about this issue were “spot on.” He added:

“Because the main goal of the CDC was to increase vaccination rates, the agency was biased and did not bring forward important safety information on a timely basis.

“The CDC should have installed an independent data safety and monitoring board to meet monthly during the campaign. Likely such a board would have shut down the CDC’s COVID-19 vaccine program for excess mortality in January 2021.”

Despite these critiques, NASEM lauded ISO’s pandemic work.

The ISO “carried out scientifically robust, timely, and effective monitoring and evaluation of vaccine risks throughout the COVID-19 pandemic,” NASEM concluded. “Its proactive identification of emerging vaccine risk concerns informed critical public health decisions.”

Recommendations focused on rebuilding confidence in the system

The NASEM committee expressed concern that its own focus in the report on the risks of the COVID-19 vaccines could detract from “the overwhelming evidence of their benefit.”

The committee offered recommendations for a more robust risk monitoring system in hopes that a better system would “increase understanding of and confidence in federal studies of vaccine risks.”

Recommendations included improving integration of the health data surveillance system, identifying and reviewing safety signals more quickly, clarifying communication, providing sufficient long-term budget and staffing to ISO, and encouraging methodological innovation.

The committee also encouraged transparency in communication and in the data used to make risk evaluations. Hooker said he agreed with those recommendations, and noted that researchers have been trying to get access to that data for decades.

All vaccine safety data should be deidentified and shared with independent researchers, Hooker said. McCullough and Hooker agreed that NASEM’s proposal — that ISO should be completely separated from the offices of the CDC that advocate vaccination — was important.

“This recommendation is notable as it separates vaccine safety and vaccine advocacy,” Hooker said. “We’ve been calling for this for 25 years, and it is high time that the ISO woke up and smelled the coffee.”