The LISTEN Study

The study was led by esteemed professors Dr. Harlan Krumholz, a cardiologist, and Dr. Akiko Iwasaki, an immunologist, both of whom have made notable contributions to their fields. Their leadership in a study addressing vaccine safety concerns warrants attention.

Named LISTEN (Listen to Immune, Symptom and Treatment Experiences Now), the research focused on 241 adults who self-reported symptoms of post-vaccination syndrome (PVS) after receiving Covid-19 vaccinations from May 2022 to July 2023.

Among the participants, 55% received Pfizer’s mRNA vaccine, 37% received Moderna’s mRNA vaccine, and the remaining 8% were administered AstraZeneca’s DNA, Johnson & Johnson’s DNA, or Novavax’s subunit vaccines. The median participant age was 46, predominantly female and White, with over 80% hailing from the U.S. Notably, 34% had a prior Covid-19 infection.

Participants were asked to fill out a thorough survey about their symptoms. The median duration from vaccination to survey response was 595 days (approximately 19.5 months), with a range of 40 to 1,058 days.

Key findings from the survey include:

• Mental Health: In the week leading up to the survey, 98% reported feeling fatigued, 93% experienced unease, and substantial numbers reported feelings of fear, anxiety, and depression. Many indicated a lack of social support and feelings of loneliness.
• Physical Symptoms: The median time from vaccination to the onset of symptoms was 3 days, with participants reporting an average of 22 symptoms. The most common included exercise intolerance (71%), fatigue (69%), and brain fog (63%). A significant 86% reported that these symptoms affected their daily lives.
• New Diagnoses: Among the participants, 36% were diagnosed with anxiety, 33% with neurological issues, and 30% with gastrointestinal problems.
• Treatment Attempts: Participants explored a total of 209 different treatments, with probiotics and vitamins being the most common. Despite these efforts, many reported a diminished quality of life.

The LISTEN study stands out as the largest to characterize a possible new condition called post-vaccination syndrome (PVS). The short interval between the onset of PVS symptoms and Covid-19 vaccination strongly suggests a potential link.

The authors emphasized that participants had no other medical conditions that could clarify their symptoms, and those with long-Covid were specifically excluded from the analysis.

They concluded, “Individuals reporting PVS post-Covid-19 vaccination in this study are significantly symptomatic, face poor health outcomes, and have engaged in various treatment options with limited success.” They highlighted the urgent need to understand PVS to develop effective prevention, diagnosis, and treatment strategies.

The Broader Context: Causality

As acknowledged by the study's authors, “This observational study of self-referred individuals cannot determine causality or provide estimates of the incidence and prevalence of PVS.”

Observational studies inherently lack the ability to confirm cause-and-effect relationships; this capability is reserved for randomized clinical trials. Such trials ensure a balanced distribution of known and unknown variables, allowing researchers to attribute observed effects to the intervention rather than external factors.

Furthermore, the absence of control groups in the LISTEN study weakens its findings. Without a comparison group, we cannot ascertain whether vaccinated individuals are at a greater risk of developing PVS than their unvaccinated counterparts. Thus, the LISTEN study resembles a case series — a collection of case reports — rather than a robust cohort study.

Even if control groups had been included, proving that Covid-19 vaccination is the root cause of reported health issues remains challenging.

Long-Covid faces similar dilemmas.

In a previous article on Medium, I discussed how long-Covid diagnostic criteria often fall prey to the post hoc, ergo propter hoc fallacy, which suggests that if symptom X occurs after event Y (Covid-19 or vaccination), then Y must be the cause of X.

Specifically, long-Covid is diagnosed based on the persistence of symptoms for 12 weeks or longer after a Covid-19 infection, with no other explanations available. Questionnaires typically inquire if participants experienced any new symptoms lasting three months or more following their Covid-19 diagnosis.

This simplistic approach raises questions about the actual causative relationship between Covid-19 and chronic symptoms. While it is clear that individuals with long-Covid are experiencing real health issues, undiagnosed conditions or stress from the pandemic might also contribute to their symptoms.

A similar caution applies to post-vaccination syndrome (PVS). However, it is important to note that long-Covid is better supported by extensive research into its prevalence and underlying mechanisms, unlike PVS.

Dr. Jennifer Frontera, a neurocritical care expert at NYU Langone Health, expressed concern regarding the terminology of “post-vaccination syndrome,” noting that it inadvertently suggests causality.

The Broader Context: Confounding Factors

Several confounding factors may also play a role in the emergence of PVS. Confounders are variables that can obscure true associations and lead to misleading conclusions.

Dr. Frontera indicated that many participants reported pre-existing health conditions even before the pandemic. About 75% had at least one comorbidity, including gastrointestinal issues (28%), anxiety (25%), and depression (20%). While the study's authors claimed these conditions couldn't account for PVS symptoms, no specific tests were conducted to validate this assertion.

Additionally, Dr. Linda Geng, co-director of a long-Covid center at Stanford University, pointed out that PVS symptoms often overlap with those of long-Covid. Although the study excluded individuals with a long-Covid diagnosis, Geng noted that self-identification can be unreliable.

Confirming a long-Covid diagnosis is indeed complex, as no definitive medical test exists for it. Consequently, some individuals might have unknowingly contracted Covid-19, with asymptomatic cases potentially resulting in long-Covid. In the LISTEN study, 34% of participants reported a prior SARS-CoV-2 infection, but no serological tests were conducted to verify past exposure.

Lastly, we must consider the influence of other factors. Chronic fatigue has long affected a considerable portion of the population, even before the pandemic. The correlation between the 10-30% of Covid-19 survivors who develop long-Covid and pre-existing fatigue raises questions about potential overlapping causes.

Common contributors to fatigue include:

• Lifestyle: Poor sleep, substance use, and stress.
• Pre-existing conditions: Such as anxiety, depression, and chronic diseases.
• Unknown origins: Chronic fatigue syndrome (CFS), which may stem from viral infections or immune system changes.

Thus, the pre-existing fatigue may lead to misattributions of PVS or long-Covid diagnoses.

Research indicates that Covid-19 vaccines may protect against long-Covid and chronic fatigue. A 2023 meta-analysis involving over 546,000 unvaccinated individuals compared to 8,405 vaccinated found a 36% and 38% reduction in long-Covid and persistent fatigue risks, respectively.

Conclusion

A noteworthy aspect of the LISTEN study is the brief interval between Covid-19 vaccination and the onset of PVS symptoms, with a median of just 3 days. This correlation suggests a potential association that cannot be easily dismissed.

However, even this connection remains speculative. In the context of widespread vaccination, it is plausible that some individuals may develop unusual chronic conditions shortly after receiving their vaccine.

Ultimately, while the Yale LISTEN study highlights 241 individuals with self-reported PVS, its observational design and lack of control groups limit its applicability to the general population. The potential impact of other factors — pre-existing health issues, pandemic-related stress, and unrecognized infections — cannot be ignored.

Considering these elements, the actual number of individuals experiencing PVS attributable to Covid-19 vaccination may be significantly lower than 241. This does not undermine the genuine health concerns of those experiencing PVS; it simply highlights the uncertainty surrounding the causative role of the vaccine. Given the stakes involved, we should adopt a cautious approach, maintaining the principle of "innocent until proven guilty" regarding Covid-19 vaccines.

For further exploration of long-Covid topics, I have compiled a list of relevant articles on Medium.

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<h2>Long-COVID: What's Still Relevant</h2>

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<div><p>shinjieyong.medium.com</p></div>

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