Fact Check: COVID vaccines do not work

COVID Vaccines Do Not Work: A Detailed Examination of the Claim

Introduction

The claim that "COVID vaccines do not work" has circulated widely, particularly in discussions surrounding vaccine efficacy and public health policy. This assertion raises significant questions about the effectiveness of COVID-19 vaccines, especially in light of emerging variants and changing public health recommendations. This article aims to analyze the available evidence regarding the effectiveness of COVID-19 vaccines, focusing on recent data and expert opinions.

What We Know

1. Vaccine Recommendations: The CDC's Advisory Committee on Immunization Practices recommended updated COVID-19 vaccinations in September 2023 for all individuals aged six months and older to prevent severe disease caused by the virus 1.

2. Vaccine Effectiveness (VE): Recent studies indicate that the effectiveness of COVID-19 vaccines can vary significantly. For instance, a study published in August 2024 reported an estimated vaccine effectiveness of 42% before the JN.1 lineage became dominant and only 19% afterward 5.

3. Real-World Effectiveness: Another study highlighted that vaccines administered during the autumn 2023 campaigns showed clinically significant effectiveness against symptomatic SARS-CoV-2 infection for at least three months post-vaccination 6.

4. Waning Immunity: Data from the CDC indicates that vaccine effectiveness against hospitalization in immunocompromised individuals waned to nearly zero within four to six months after vaccination 3.

5. Population-Level Estimates: Vaccine effectiveness is often reported as a population-level estimate, which can be influenced by high rates of natural immunity due to previous infections 2.

6. Lack of Randomized Controlled Trials: The introduction of monovalent vaccines targeting the XBB.1.5 variant in September 2023 was not supported by randomized controlled trials, which raises questions about the robustness of the effectiveness data 4.

Analysis

The claim that COVID vaccines do not work can be dissected through various lenses, including the reliability of sources, the context of the data, and the methodology used to assess vaccine effectiveness.

Source Reliability

• CDC Reports: The CDC is a primary source for public health information in the United States. While it is generally considered a reliable source, it can be subject to political and public scrutiny, especially regarding its recommendations and data interpretations. The agency's reports are based on extensive data collection and analysis, but they may also reflect public health priorities that could influence how effectiveness is communicated.

• Peer-Reviewed Studies: Articles published in peer-reviewed journals, such as those referenced from PubMed and The Lancet, typically undergo rigorous evaluation, lending credibility to their findings. However, the context of the studies—such as sample size, population demographics, and the specific variants studied—must be critically assessed to understand the applicability of their conclusions.

Conflicting Evidence

• Some studies suggest that while vaccines may offer reduced effectiveness against certain variants, they still provide significant protection against severe illness and hospitalization 78. Conversely, other studies indicate a marked decline in effectiveness over time, particularly in immunocompromised populations 35.

• The interpretation of vaccine effectiveness can also be influenced by the prevalence of natural immunity in the population, which complicates the assessment of how well vaccines are performing in real-world scenarios 2.

Methodological Concerns

• The lack of randomized controlled trials for the latest vaccine formulations raises concerns about the strength of the evidence supporting their effectiveness 4. Observational studies can provide valuable insights but are often subject to confounding factors that may skew results.

• Additionally, the reliance on population-level estimates can obscure individual experiences and outcomes, leading to generalizations that may not apply universally.

Conclusion

Verdict: False

The claim that "COVID vaccines do not work" is assessed as false based on a comprehensive review of available evidence. While there are variations in vaccine effectiveness, particularly against emerging variants and in specific populations, substantial data indicate that COVID-19 vaccines continue to provide significant protection against severe illness and hospitalization. Recommendations from health authorities, such as the CDC, support the ongoing use of vaccines to mitigate the impact of COVID-19.

However, it is important to acknowledge the nuances in vaccine effectiveness. Studies indicate that effectiveness can wane over time, especially in vulnerable populations, and that the lack of randomized controlled trials for newer formulations raises questions about the robustness of some findings. Additionally, the influence of natural immunity complicates the overall assessment of vaccine performance.

Limitations in the available evidence, such as the reliance on observational studies and population-level estimates, mean that conclusions should be drawn with caution. Readers are encouraged to critically evaluate information and consider the broader context of public health recommendations and scientific findings.

Sources

1. Centers for Disease Control and Prevention. (2024). Interim Effectiveness of Updated 2023–2024 (Monovalent XBB.1.5) COVID-19 Vaccination. Retrieved from CDC
2. Centers for Disease Control and Prevention. (2024). Effectiveness of COVID-19 (2023-2024 Formula) vaccines. Retrieved from CDC
3. Centers for Disease Control and Prevention. (2024). COVID-19 vaccine effectiveness. Retrieved from CDC
4. PubMed. (2025). Effectiveness of the 2023-to-2024 XBB.1.5 COVID-19 Vaccines. Retrieved from PubMed
5. PubMed. (2024). Effectiveness of the 2023-2024 Formulation of the COVID-19 Vaccines. Retrieved from PubMed
6. PMC. (2024). Effectiveness of COVID-19 vaccines administered in the 2023 campaigns. Retrieved from PMC
7. CIDRAP. (2024). COVID vaccine efficacy against severe illness just under 50%. Retrieved from CIDRAP
8. The Lancet. (2023). Long-term effectiveness of COVID-19 vaccines against severe illness. Retrieved from The Lancet
9. ACP Journals. (2024). Effectiveness of the 2023-to-2024 XBB.1.5 COVID-19 Vaccines. Retrieved from ACP Journals.)
10. Yale Medicine. (2024). Comparing the COVID-19 Vaccines: How Are They Different? Retrieved from Yale Medicine