Scientists warned in 2009 that Vaccinia virus in current Mpox vaccines impairs critical immune functions

Medical News: A Glimpse into the Past: The Warning That Went Unheeded
In 2009, a group of scientists from the Brody School of Medicine at East Carolina University-USA, led by Dr. Rachel L. Roper, raised alarm bells about the potential dangers of the Vaccinia virus (VACV) used in Mpox (previously known as monkeypox) and smallpox vaccines. Their groundbreaking research, published in a peer-reviewed journal, indicated that the virus might impair critical functions of the immune system, specifically targeting antigen-presenting cells (APCs). This Medical News report delves into their findings and the implications that continue to resonate today.


Scientists warned in 2009 that Vaccinia virus in current Mpox vaccines impairs
critical immune functions

It should be noted that while these vaccines were ‘seemingly ok’ in the past, we are currently in a different situation as we have huge populations of people already having immune dysfunction issues caused by COVID-19, SARS-CoV-2 reinfections and even by the COVID-19 mRNA vaccines. We also have growing populations of people with HIV and cancer and as such immunocompromised to a certain degree and also many who had been exposed to measles recently not forgetting that we are dealing with newer strains of Mpox now.
 
Understanding the Role of Antigen-Presenting Cells
Antigen-presenting cells are a crucial component of the immune system, responsible for detecting and presenting foreign antigens to T cells. This interaction is vital for initiating an effective immune response against pathogens. The study conducted by Dr. Roper and her team highlighted how VACV, the virus used in smallpox and Mpox vaccines, disrupts this critical process, potentially weakening the body's ability to fight off infections.
 
According to the research, VACV significantly decreases the presentation of major histocompatibility complex (MHC) class II molecules, which are essential for the activation of T cells. The virus also impairs the production of important cytokines and chemokines, further inhibiting the immune response. This article provides a detailed analysis of these findings and their potential implications for vaccine safety.
 
Key Findings of the Study
The study focused on how VACV interacts with different types of antigen-presenting cells, including macrophages, dendritic cells, and B cells. The researchers found that VACV infection led to a significant reduction in MHC class II antigen presentation across all these cell types. This reduction was linked to a decrease in the amount of antigenic peptide loaded into MHC class II molecules, which is essential for T cell activation.
 
The researchers discovered that VACV specifically targets macrophages and dendritic cells, inducing apoptosis (programmed cell death) in these cells. This apoptosis contributes to the impaired antigen presentation, further weakening the immune response. Interestingly, B cells were affected differently; while VACV reduced their ability to present antigens, it did not induce apoptosis in these cells, suggest ing a distinct mechanism of immune evasion by the virus.
 
Implications for Vaccine Safety
The findings of this study raise important questions about the safety and efficacy of vaccines that use VACV as a platform. While VACV-based vaccines have been highly effective in eradicating smallpox and controlling Mpox outbreaks, the potential for immune suppression poses a significant concern, especially for individuals with compromised immune systems.
 
The researchers noted that VACV's ability to impair antigen presentation could lead to reduced vaccine efficacy, particularly in individuals with pre-existing conditions or weakened immune systems. This impairment might also increase the risk of adverse reactions, such as disseminated poxvirus infections, which have been reported in some vaccine recipients.
 
The Broader Context: Immune Evasion by Poxviruses
Poxviruses, including VACV, are known for their ability to evade the host immune system. The study by Roper and her team adds to the growing body of evidence that these viruses employ multiple strategies to subvert immune defenses. In addition to impairing antigen presentation, VACV has been shown to block the production of nitric oxide (NO), a key molecule involved in antiviral defense. The virus also reduces the expression of MHC class II molecules on the surface of APCs, further hindering the immune response.
 
The study findings highlight the importance of understanding these immune evasion mechanisms, as they have significant implications for vaccine design and the development of antiviral therapies. The study findings underscore the need for continued research into the interactions between VACV and the immune system, particularly in the context of vaccine safety.
 
Expanding on the Study's Findings
The study conducted by the Brody School of Medicine at East Carolina University was comprehensive, employing various experimental models to investigate the effects of VACV on antigen presentation. The researchers used rat peritoneal macrophages, dendritic cells, and a mouse B-cell line to assess how VACV infection impacts the immune response.
 
Their experiments revealed that VACV infection significantly reduced the production of interleukin-2 (IL-2), a critical cytokine for T cell activation, in response to antigen presentation. This reduction was observed across different types of APCs, indicating that VACV has a broad impact on the immune system. The researchers also found that increasing the concentration of antigens could partially restore antigen presentation in infected cells, suggesting that VACV disrupts antigen processing rather than directly killing APCs.
 
The study also explored how VACV affects cytokine production in response to antigen presentation. The researchers found that VACV infection led to a significant decrease in the production of multiple cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), and macrophage inflammatory protein-1 alpha (MIP-1α). These cytokines play essential roles in coordinating the immune response and recruiting immune cells to the site of infection.
 
Conclusion: The Need for Caution and Further Research
The study's findings highlight the complex interplay between VACV and the immune system, raising important questions about the long-term safety and efficacy of VACV-based vaccines. While these vaccines have been instrumental in controlling poxvirus outbreaks, the potential for immune suppression cannot be overlooked.
 
As the world continues to grapple with emerging infectious diseases, the need for safe and effective vaccines has never been greater. This article underscores the importance of continued research into the immune evasion mechanisms employed by VACV and other poxviruses. Such research is crucial for developing next-generation vaccines that are both safe and effective, particularly for vulnerable populations.
 
The study findings were published in the peer-reviewed journal Immunology.
https://onlinelibrary.wiley.com/doi/10.1111/j.1365-2567.2009.03120.x
 
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https://www.thailandmedical.news/news/norwegian-doctors-warn-that-mpox-vaccines-can-cause-generalized-pustular-psoriasis-in-some
 
https://www.thailandmedical.news/news/danish-biotech-under-fire-for-alleged-profiteering-from-vaccines-amid-global-mpox-crisis