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Background：

The U.S. Centers for Disease Control and Prevention (CDC) will hold a two-day meeting of the Advisory Committee on Immunization Practices (ACIP) this week (September 18-19). The meeting will cover topics including epidemiological updates on routine vaccines and COVID-19 vaccines, vaccine effectiveness, safety updates, and economic analyses. Regarding the COVID-19 vaccine agenda, discussions may address 25 cases of child deaths potentially linked to vaccination. Because the topic involves child safety, pandemic prevention policies, and public health measures, it has attracted significant attention from international media and could potentially raise public concerns about vaccination, underscoring the need for comprehensive scientific information.

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ACIP Information

What is the current COVID-19 situation in Taiwan? If you have previously received a COVID-19 vaccine or have been diagnosed with COVID-19, do you still need to get the new vaccine? Does Taiwan have a vaccine safety monitoring system? The Taiwan Science Media Center has invited experts to provide insights on how the public should understand the relationship between vaccines and death cases.

Expert reaction:

September 16, 2025

Ruey-Hong Weng, Professor, Department of Public Health, Chung-Shan Medical University / Chairman, Taipei Public Health Specialists Association

1. Current COVID-19 Situation and the Necessity of Vaccination 

Currently, the COVID-19 epidemic in Taiwan is at a low level of transmission, but it has not yet been entirely eradicated. According to Taiwan Centers for Disease Control data, during the first week of September (9/2–9/8), there were 16 new severe cases and two deaths, mainly among the elderly or patients with chronic illnesses. So far this year (2025), there have been a total of 1,652 severe cases and 381 deaths (statistics as of September 17), with over 80% of these individuals not having received the latest JN.1 vaccine. Such highlights the importance of vaccination in reducing risk. Because the virus continues to mutate, protection from past infections or older vaccines diminishes over time. Therefore, even those who have been previously vaccinated or infected are still advised to receive the new vaccine booster, especially the elderly and those with chronic conditions, as it can effectively reduce the risk of severe illness and death.

 2. Epidemiological Interpretation of Vaccine-Related Death Causality 

Determining whether a vaccine causes death cannot be based solely on individual cases or intuition; it requires systematic analysis. Clinical and autopsy investigations can confirm the immediate cause of death, but are insufficient to establish the vaccine as a proximate cause. Accurate causal inference/assessment requires comparing mortality rates between vaccinated and unvaccinated groups in comparable populations. If the death rate in the vaccinated group is significantly higher, this may indicate a vaccine-related risk; otherwise, a causal relationship is not supported. Interpretation should follow principles of causal inference, including temporality, biological plausibility, consistency, and dose-response relationships. In other words, while individual deaths can reveal causes of death, vaccine causality must be assessed based on large-scale studies and surveillance data.

 3. Taiwan’s monitoring system

Taiwan maintains an adverse-event reporting and injury compensation program, with expert panels assessing the causality of injuries. For COVID-19 vaccines, of nearly 8,000 applications since 2021, about 3% were determined to have a causal link to vaccination. Most deaths were attributable to pre-existing conditions; a small number were associated with rare events such as vaccine-induced immune thrombotic thrombocytopenia (VITT) following adenoviral-vector vaccines. The system is comprehensive and transparent, enabling fair communication and international comparison.

4. Communicating to sustain public trust in vaccines

Trust depends on transparent data, candid communication, and institutional safeguards. Authorities should publish adverse-event data alongside baseline mortality rates and clearly explain benefits and risks in accessible, empathetic language. Clinicians, public-health specialists, and experts should communicate findings to counter misinformation. Compensation and monitoring mechanisms should be visible so people know where to seek help if problems arise. Combining transparent data, expert explanation, empathetic communication, and system-level protections can strengthen public confidence.

September 18, 2025

Chen-I Kuan, Associate Professor, Institute of Health Behavior and Community Sciences, College of Public Health, National Taiwan University

According to information obtained by The Washington Post from internal government sources, officials within the Trump administration are expected to raise a motion concerning the “potential association between COVID-19 vaccines and the deaths of 25 children in the United States” at the upcoming meeting of the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices (ACIP), scheduled for September 18 (10:00 a.m. EST) and September 19 (8:30 a.m. EST).

The ACIP has long served as an established review mechanism within the CDC’s vaccine governance structure. It convenes three regular meetings annually and, when necessary, calls additional sessions. At these meetings, the committee examines the latest scientific data, invites input from civil society organizations and individuals, and deliberates publicly on matters of vaccine policy. Decisions are ultimately made through committee votes, which determine whether specific vaccines are recommended. Literature on vaccine hesitancy underscores that transparent and open responses to public concerns are crucial for strengthening societal trust in immunization. Indeed, during the height of the COVID-19 pandemic in 2020 and 2021, the ACIP held multiple hearings on the efficacy and safety of COVID-19 vaccines. These “marathon-style” discussions, each lasting three to five hours or longer, were seen as a demonstration of the government’s willingness to address public concerns, facilitating the rollout of the COVID-19 vaccine in December 2020 and its rapid global dissemination, which ultimately saved countless lives.

The forthcoming ACIP meeting, however, has already sparked controversy. Concerns arise from a series of politically charged events in recent months, ostensibly carried out in the name of “restoring public trust.” Notably, the Secretary of Health, who has consistently signaled strong anti-vaccine positions, dismissed all 17 ACIP members in late June, claiming that conflicts of interest within the committee were the primary barrier to public trust. Several new appointees included prominent vaccine skeptics. Moreover, the Secretary has published a statement contradicting with that of a former CDC director. The current CDC director was dismissed last month after refusing to endorse a contested vaccine policy. More alarmingly, the Secretary unilaterally revoked certain vaccine recommendations for individuals with specific health conditions, despite a lack of compelling scientific evidence. Against this backdrop, uncertainty and apprehension now surround the impending ACIP proceedings.

In sum, while transparent and inclusive discussion is indispensable for fostering public confidence in vaccines, research consistently demonstrates that the politicization of vaccine information and deliberation is one of the key drivers of vaccine hesitancy. The forthcoming deliberations within the United States therefore carry significant uncertainty and warrant close scrutiny.

September 18, 2025 

Chia-Yu Chi, Associate Research Fellow and Attending Physician, Institute of Infectious Diseases and Vaccinology, National Health Research Institutes

Between 2020 and 2024, COVID-19 vaccination saved an estimated 2.5 million lives worldwide, with especially strong effects in preventing severe disease and death among adults aged ≥60 years. As the virus has evolved, debates have emerged over target populations and vaccination mandates. Some experts emphasize that vaccines may also lower risks of long COVID, cardiovascular complications, and cognitive sequelae, and that irregular uptake among healthcare workers could increase transmission to immunocompromised patients. Others note that many benefit estimates come from observational studies subject to residual bias and confounding, arguing that randomized controlled trials (RCTs) are needed to more precisely quantify booster effectiveness.

Despite these debates, experts agree that high-risk groups should be prioritized for vaccination.

UK experience. Since 2023, the United Kingdom has limited vaccination to high-risk groups. In 2025, the Joint Committee on Vaccination and Immunisation (JCVI)—with adoption by the government and the National Health Service (NHS)—recommended priority vaccination for: (1) adults ≥75 years; (2) residents of care homes for older adults; and (3) individuals aged ≥6 months with severe immunosuppression. Vaccination is offered mainly in spring and autumn, using monovalent mRNA vaccines updated to circulating variants.

COVID-19 Vaccine Protection

Although COVID-19 activity is milder in 2025 than at prior peaks, the virus continues to circulate, and hospitalizations and deaths still rise in the fall and winter. Most infections are mild, but older adults and people who are immunocompromised remain at elevated risk of severe outcomes. Protection from prior vaccination or infection against infection and transmission typically wanes within approximately 3–6 months; protection against severe disease is more durable but also declines. Updated vaccines matched to circulating variants can restore immunity ahead of the fall and winter and reduce the risks of severe illness and death. This is especially important for adults aged 75 and older and those who are immunocompromised. Accordingly, high-risk groups are advised to receive updated boosters even after previous vaccination or infection.

Impact of COVID-19 Infection and Vaccination in Children

On September 1, 2025, the UK Health Security Agency updated the COVID-19 chapter in the Green Book, noting that most children who become infected experience asymptomatic or mild cases, especially following the spread of the Omicron variant. Severe hospitalizations are rare, and deaths are even more uncommon.

According to research reports, individuals aged 25 and under—particularly males—have a higher reported rate of myocarditis and pericarditis after receiving mRNA vaccines. However, these cases generally occur within a few days after vaccination; most are mild and recover well. Other rare reported symptoms include temporary, non-severe changes in menstrual flow, localized swelling at the injection site, and hives.

Because severe illness in children is extremely rare, the UK government updated its vaccination recommendations for children in 2025. Booster doses are still advised for clinically high-risk groups, such as children aged six months and older with severe chronic illnesses, immunodeficiencies, or Down syndrome with immunosuppressed condition.

Impact of Infection and Vaccination on Pregnant Women

Pregnant individuals face higher risks of severe COVID-19 than non-pregnant peers, including increased ICU admission, invasive ventilation, and ECMO, with additional risks associated with obesity, diabetes, and age ≥35 years. Although Omicron tends to be less severe than Delta, unvaccinated pregnant people remain at higher risk than those vaccinated. The UK therefore prioritizes pregnant individuals in seasonal programs to reduce severe maternal illness and adverse outcomes (e.g., preterm birth, stillbirth). The Medicines and Healthcare products Regulatory Agency (MHRA) and UKHSA jointly run the UK Vaccine in Pregnancy surveillance program; to date, no safety signals specific to pregnancy have emerged. Regulators in the WHO, United States, Canada, and the European Union report similar findings. In the United States, more than 100,000 pregnant individuals—mostly receiving mRNA vaccines—have been vaccinated without identified safety concerns. Pfizer-BioNTech and Moderna mRNA vaccines are preferred in pregnancy. mRNA of vaccine strain is not detected in breast milk, whereas protective antibodies are, suggesting potential passive infant protection; breastfeeding is compatible with vaccination.

Contraindications

True contraindications are rare. People should avoid the same vaccine product if they experienced: (1) anaphylaxis to a prior dose; (2) a known severe allergy to a vaccine component (e.g., PEG in mRNA vaccines); or (3) myocarditis/pericarditis after a prior dose. Those with a high fever or active COVID-19 infection should defer vaccination until recovery.

References：

1. Pappas, G. et.al. (2025) An Evidence-Based Approach to Covid-19 Vaccination. New England Journal of Medicine. doi: 10.1056/NEJMc2507760

2. Gandhi, M. (2025) COVID-19 Vaccination Saved Lives and This Matters in 2025. JAMA Health Forum. 6(7), e252237. doi: 10.1001/jamahealthforum.2025.2237

3.  Guidance－The safety of COVID-19 vaccines when given in pregnancy.