Report on the Advisory Committee on Immunization Practices Meeting and Thimerosal Safety

Introduction

On June 25-26, 2025, the Advisory Committee on Immunization Practices (ACIP), an expert committee advising the Centers for Disease Control and Prevention (CDC) on vaccines, convened for the first time since Health Secretary Robert F. Kennedy Jr. replaced its 17 members with eight hand-picked members on June 11, 2025. The committee’s agenda included discussions and votes on vaccines for COVID-19, human papillomavirus, influenza, and other infectious diseases, as well as a presentation and vote on the use of thimerosal in influenza vaccines.

Emphasis on Sustainable Development Goals (SDGs)

• SDG 3: Good Health and Well-being – Ensuring the safety and efficacy of vaccines supports global health and prevents infectious diseases.
• SDG 4: Quality Education – Providing accurate, evidence-based information about vaccine safety combats misinformation and promotes informed health decisions.
• SDG 17: Partnerships for the Goals – Collaboration between public health experts, regulatory agencies, and international organizations like WHO strengthens vaccine policies and public trust.

Thimerosal: Definition and Use

Thimerosal, also known as thiomersal, is a preservative used in some drug products since the 1930s to prevent microbial contamination. In the human body, it metabolizes into ethylmercury, which studies show is rapidly eliminated from the bloodstream, distinguishing it from the toxic methylmercury found in the environment.

Key Facts About Thimerosal

1. Used as a preservative to prevent contamination in vaccines and other drug products.
2. Metabolized into ethylmercury, which is quickly cleared from the body.
3. Not to be confused with methylmercury, a neurotoxin linked to brain development issues.

Controversies Surrounding Thimerosal

Concerns about thimerosal’s safety stem from two main sources:

1. The 1998 discredited study by Andrew Wakefield falsely linking vaccines to autism, which did not involve thimerosal and was later retracted.
2. Confusion between ethylmercury in thimerosal and methylmercury, leading to unfounded fears about autism and developmental disorders.

Impact of Misinformation

• Damaged public trust in vaccines, particularly the MMR vaccine.
• Increased vaccine hesitancy, posing challenges to achieving SDG 3 by hindering disease prevention efforts.

Scientific Evidence on Thimerosal Safety

Extensive research has found no evidence linking thimerosal to autism or other developmental disorders. Key findings include:

• A 1999 FDA review found no harm from thimerosal except rare allergic reactions.
• The American Academy of Pediatrics and U.S. Public Health Service recommended removing thimerosal from vaccines as a precautionary measure.
• By 2001, thimerosal was removed from almost all childhood vaccines in the U.S.
• The 2004 Institute of Medicine review of over 200 studies concluded no causal relationship between thimerosal-containing vaccines and autism.
• Subsequent CDC and FDA reviews confirmed the absence of links between thimerosal and neuropsychological delays.

Contribution to SDGs

• Supports SDG 3 by ensuring vaccine safety and maintaining public health.
• Promotes SDG 4 through dissemination of scientifically validated information.

Current Use of Thimerosal

Today, thimerosal is primarily found in multidose vials of influenza vaccines used in large-scale immunization efforts. It is not present in modern childhood vaccines in the U.S., and single-dose vaccine options without thimerosal are available for those who prefer them. The World Health Organization continues to endorse the safety of thimerosal-containing vaccines worldwide.

Relevance to Sustainable Development Goals

• SDG 3: Facilitates widespread immunization by preserving vaccine availability and safety.
• SDG 17: Reflects global health partnerships ensuring vaccine access and safety standards.

Conclusion

The ACIP meeting underscores the ongoing commitment to vaccine safety and public health, aligning with the Sustainable Development Goals by promoting well-being, combating misinformation, and fostering international cooperation. Scientific evidence consistently supports the safety of thimerosal in vaccines, reinforcing trust in immunization programs critical to global health.

1. Sustainable Development Goals (SDGs) Addressed or Connected

1. SDG 3: Good Health and Well-being
   • The article focuses on vaccine safety, immunization practices, and public health concerns, which directly relate to ensuring healthy lives and promoting well-being for all ages.
2. SDG 4: Quality Education
   • By addressing misinformation and promoting scientific evidence about vaccines, the article supports informed decision-making and education on health topics.
3. SDG 16: Peace, Justice, and Strong Institutions
   • The article touches on scientific integrity, ethical standards in research, and public trust in health institutions, which relate to building effective, accountable institutions.

2. Specific Targets Under Those SDGs

1. SDG 3: Good Health and Well-being
   • Target 3.3: End the epidemics of communicable diseases including vaccine-preventable diseases.
   • Target 3.8: Achieve universal health coverage, including access to quality essential health-care services and safe, effective vaccines.
   • Target 3.b: Support the research and development of vaccines and medicines for communicable and non-communicable diseases.
2. SDG 4: Quality Education
   • Target 4.7: Ensure that all learners acquire knowledge and skills needed to promote sustainable development, including health literacy.
3. SDG 16: Peace, Justice, and Strong Institutions
   • Target 16.6: Develop effective, accountable and transparent institutions at all levels, including scientific advisory bodies.
   • Target 16.10: Ensure public access to information and protect fundamental freedoms, which includes combating misinformation.

3. Indicators Mentioned or Implied to Measure Progress

1. SDG 3 Indicators
   • Immunization coverage rates for vaccines such as influenza, COVID-19, and human papillomavirus (HPV) vaccines.
   • Incidence and prevalence rates of vaccine-preventable diseases.
   • Monitoring adverse events following immunization to ensure vaccine safety.
2. SDG 4 Indicators
   • Levels of public knowledge and awareness about vaccine safety and effectiveness.
   • Reduction in misinformation related to vaccines as measured by surveys or studies.
3. SDG 16 Indicators
   • Transparency and accountability measures of health advisory committees (e.g., composition and functioning of the Advisory Committee on Immunization Practices).
   • Public trust in health institutions and scientific recommendations.
   • Incidence of misinformation or disinformation campaigns related to vaccines.

4. Table of SDGs, Targets, and Indicators

Source: theconversation.com