SARS Lessons Unlearned: Critical Questions About the Long-Term Effects of Vaccination and Repeated Viral Exposure

Dr. Philip McMillan, John McMillan

In 2011, at a quiet animal research facility in Galveston, Texas, scientists carefully administered experimental SARS vaccines to six- to eight-week-old female mice. Their research, conducted between rows of cages separated by barrier filters, was part of a global effort to develop vaccines against the newly emerged SARS coronavirus that had caused a global panic in 2003. Other facilities on other continents diligently carried out similar experiments on ferrets, mice, and non-human primates to develop effective solutions against future pandemics.

Uneventful weeks of careful monitoring went by until the moment of truth β€” the “challenge study,” where the vaccinated animals were exposed to live SARS virus. Everything seemed fine, at first. The animals displayed no obvious symptoms and appeared to be protected from infection. However, subsequent autopsy analysis confirmed that the very vaccines meant to be a protective shield had sensitized their immune systems, leading to a dangerous overreaction when faced with the real virus. These experiments indicated that the path to a safe SARS vaccine was going to be far more complex than anyone had imagined. The findings of this trial, published in 2012, should have served as a cautionary tale for future coronavirus vaccine development, especially for the catastrophic pandemic that would erupt just eight years later.

COVID-19: A Real-World Challenge Study

The ongoing COVID-19 pandemic has raised critical questions about the long-term effects of vaccination and repeated viral exposure. In the past, human “challenge studies,” where vaccinated individuals are deliberately exposed to a virus multiple times, might have been used by the scientific community to study these effects and identify potential future issues.

Serendipitously, high circulation of the virus in heavily vaccinated regions effectively creates a real-world challenge study scenario. The critical question is whether this will lead to problems in the future, particularly regarding immune responses and potential hypersensitivity reactions. This concern isn’t limited to vaccinated individuals. Contrary to popular belief, unvaccinated individuals may be at equal or even higher risk of developing hypersensitivity responses compared to their vaccinated counterparts, albeit through a different mechanism.

The Exosomal Shedding Hypothesis

The concept of lipid nanoparticle or exosomal shedding introduces a vector that has not been adequately considered. Exosomes, naturally produced by cells to transmit information, could potentially carry vaccine-related materials such as mRNA or spike proteins. Theoretically, vaccinated individuals could shed these exosomes through saliva or respiratory droplets. If an unvaccinated person inhales these particles and has been previously primed, they could experience hypersensitivity responses similar to allergic reactions to pollen.

While this phenomenon is not yet proven, it could manifest as unusual symptoms such as headaches, coughing, or sneezing upon exposure to vaccinated individuals. As the virus continues to circulate, we may face a surge in respiratory diseases, complicated by exosomal hypersensitivity responses.

Current COVID-19 vaccines differ significantly from those used in the animal SARS-CoV studies. This is especially true of mRNA vaccines, which stimulate the production of IgG4, a tolerant antibody that may reduce the likelihood of immune pathology in the lungs upon re-exposure to the virus. However, this protective effect may be restricted to the lungs only, leaving other parts of the body vulnerable.

The “COVID Storm” and Future Implications

This vulnerability brings us to the concept of the “COVID storm,” a phenomenon that occurs when the virus re-enters the bloodstream upon re-exposure, potentially causing various types of immune pathology throughout the body. This concept extends beyond lung involvement and raises questions about the broader systemic effects of repeated viral exposure in vaccinated individuals.

It’s crucial to understand that even without overt symptoms, the virus can still enter the airway and attempt to infect epithelial cells. A strong mucosal response may limit the infection, but this doesn’t mean there’s no risk. Similar to pollen allergies, mere exposure to viral particles or spike proteins could potentially trigger hypersensitivity responses.

Despite these concerns, there is currently no substantial research being conducted on this topic. Ideally, “challenge studies” would involve exposing vaccinated participants to the virus and examining their lung pathology through biopsies or bronchoalveolar lavage. The apparent lack of interest in pursuing this research is worrying, given the potential long-term implications.

The situation is particularly concerning in highly vaccinated populations. Unlike regions with low vaccination rates, where there is typically strong mucosal immunity that can stop the virus before it spreads, highly vaccinated areas may see repeated infections. This puts both vaccinated and unvaccinated individuals at risk of continuous exposure to different virus variants.

As the COVID-19 pandemic continues to evolve, it’s essential that we look out for these potential risks and develop strategies to mitigate them if they occur. Ongoing scientific exploration, asking difficult questions, and reflecting on the pathology that could affect everyone are crucial steps in staying ahead of these challenges.

We must remain vigilant about potential long-term effects of repeated viral exposure in both vaccinated and unvaccinated populations. The complex interplay between vaccination, natural immunity, and repeated viral exposures can only be understood through continued research and open discussion. Only in this way can we hope to be prepared for future challenges in the face of evolving viral threats.

 

More information:
Tseng CT, Sbrana E, Iwata-Yoshikawa N, et al. Immunization with SARS coronavirus vaccines leads to pulmonary immunopathology on challenge with the SARS virus. PLoS One. 2012;7(4):e35421. doi:10.1371/journal.pone.0035421
https://pubmed.ncbi.nlm.nih.gov/22536382/
Bolles M, Deming D, Long K, et al. A double-inactivated severe acute respiratory syndrome coronavirus vaccine provides incomplete protection in mice and induces increased eosinophilic proinflammatory pulmonary response upon challenge. J Virol. 2011;85(23):12201-12215. doi:10.1128/JVI.06048-11
https://pubmed.ncbi.nlm.nih.gov/21937658/

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