Introduction
Our vaccination campaign at Marburg University Hospital started on Christmas 2020 to mitigate the regional impact of the COVID-19 pandemic. We thereby aimed to protect our high-risk patients namely elderly and immune-deficient patients as well as healthcare colleagues. In parallel, we were forced to treat an increasing number of patients suffering from long-term neurological, pneumatological, and cardiac symptoms following either severe or moderate SARS-CoV-2 infection called long-Covid or post-acute sequelae of COVID-19 (PASC). We established an interdisciplinary outpatient clinic in response to this increasing number of patients. From autumn 2021 onward, several patients appeared with typical long-Covid symptoms who never suffered from SARS-CoV-2 infections. We realized that these symptoms developed days to weeks after vaccination regardless of which vaccine was used (only BioNTech Pfizer, Moderna, and AstraZeneca were used at that time in Germany) and were changing over time (personal observation of more than 350 post-vaccination patients). Interestingly, the clinical presentation of these so-called post-vaccination (post-VAC) patients showed a strong symptom-overlap with long-Covid patients in terms of chest pain, fatigue, shortness of breath, and a variety of neurological disorders i.e., headache, pain, paresthesia, insomnia, and polyneuropathy. In addition, post-VAC patients often suffered from additional dermatological and gastro-intestinal disorders i.e., diarrhea, skin rush, and burning skin indicating that “hyper-allergic/hyperinflammatory affection” might also be involved. However, not all patients following SARS-CoV-2 infection and even significantly lesser patients post-VAC developed PASC so it is of outstanding interest to understand the underlying pathophysiology.
So far, it was the canonical understanding that using the sequence of an antigen, namely the SARS-CoV-2 spike protein for vaccination, might trigger the same pathways, but- under particular circumstances or an immunological environment- can result in the development of identical symptoms named long-Covid. Moreover, if this latter is true, are these pathways suitable targets for therapeutic interventions, and is post-VAC with its defined starting point, the clear onset of symptoms, and immunological responses a potential model to understand the pathophysiology of COVID-19? While writing this review, the manuscript by Trougakos et al. (1) was published discussing the spike protein hypothesis and potential pathways involved in adverse effects after COVID-19 vaccines. This molecular mimicry of immuno-inflammatory cascades resulting in symptoms ranging from shortness of breath, chest pain, migraine, headache, fever, and “brain fog” to other neurological symptoms which should be the target of future therapeutical interventions.
