WASHINGTON — The Centers for Disease Control and Prevention’s Immunization Safety Office (ISO) carried out scientifically robust, timely, and effective monitoring and evaluation of vaccine risks throughout the COVID-19 pandemic, says a new report from the National Academies of Sciences, Engineering, and Medicine. The office’s proactive identification of emerging vaccine risk concerns informed critical public health decisions.

The report identifies ongoing challenges related to public trust, transparency, and the perception of ISO’s independence, however. The perceived overlap between ISO’s risk monitoring activities and CDC’s broader efforts to encourage vaccine use continues to raise public concerns about the objectivity of risk assessments.

ISO should clearly distinguish its role from CDC’s efforts to encourage vaccination, the report says. 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.

“The COVID pandemic underscored ISO’s critical role in vaccine risk monitoring and evaluation,” said Jane Henney, chair of the committee that conducted the study. “ Moving forward, enhancing transparency and distinguishing ISO’s role from broader CDC efforts to encourage vaccination will be essential to address emerging vaccine risk challenges and to maintain public trust.”

Complementary systems performed well

During the pandemic, ISO used a suite of systems designed to detect, evaluate, and report potential problems associated with COVID-19 vaccines. The Vaccine Adverse Event Reporting System (VAERS) enabled clinicians, patients, and manufacturers to report signals of possible safety problems. The Vaccine Safety Datalink (VSD) offered rapid assessments and in-depth targeted analysis using electronic health records. V-safe, a new smartphone-based tool developed by CDC, let members of the public report how they felt after receiving a COVID-19 vaccine. Additional systems include the Clinical Immunization Safety Assessment (CISA) Project and the COVID-19 Vaccine Pregnancy Registry.

These platforms, each with strengths and limitations, together enabled layered and comprehensive monitoring, the report says. For example, VAERS produced the first U.S. alerts of myocarditis after mRNA vaccination in May 2021, which prompted deeper analysis in the Vaccine Safety Datalink. CISA conferences, which provided technical expertise and clinical guidance to evaluate rare or complex cases, helped shed light on the problem of blood clots linked to the Johnson & Johnson COVID-19 vaccine, which informed a decision by a CDC advisory committee to temporarily pause use of that vaccine. V-safe helped capture signals for further evaluation, such as menstrual irregularities.

While ISO’s staff and systems performed well during the public health emergency, the office should take steps to enhance transparency and continually refine its methodologies, the report says. For example, the criteria ISO used for elevating, deferring, or ceasing work on a specific safety signal were not fully explained publicly. The report urges greater transparency around those prioritization decisions.

The report also offers a set of principles and recommendations that should guide vaccine risk monitoring and evaluation going forward. For example, the office should develop and make public a strategic plan that encompasses input from health professionals, policymakers, and the public. The office should also incorporate continuous quality improvements, maintaining current systems while incorporating advances in informatics, vaccinology, and epidemiological and statistical methods.

Protecting independence and improving communication

Public comments during the National Academies’ study revealed that some people fear the safety of vaccines because of a perception that risk research and communications are biased by CDC’s efforts to increase vaccination, the report says. CDC should provide its vaccine monitoring and evaluation office with the organizational independence and resources to directly disseminate its information to health care professionals, policymakers, and the public — supports the vaccine monitoring and evaluation office currently lacks.

In addition, the office should regularly publish detailed explanations of its monitoring and evaluation systems, research methodologies, strengths, limitations, and key findings, the report says. Making these materials publicly available, along with accessible, easy-to-understand summaries and standardized risk reporting tailored for nonexpert audiences, will enhance transparency and improve public understanding and trust.

The study — undertaken by the Committee to Review the Centers for Disease Control and Prevention’s COVID-19 Vaccine Safety Research and Communications — was sponsored by the Centers for Disease Control and Prevention. The National Academies of Sciences, Engineering, and Medicine are private, nonprofit institutions that provide independent, objective analysis and advice to the nation to solve complex problems and inform public policy decisions related to science, engineering, and medicine. They operate under an 1863 congressional charter to the National Academy of Sciences, signed by President Lincoln.

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