The Post-Acute COVID-19-Vaccination Syndrome in the Light of Pharmacovigilance.

Clinical studies show that SARS-CoV-2 vaccination sometimes entails a severe and disabling chronic syndrome termed post-acute-COVID-19-vaccination syndrome (PACVS). PACVS shares similarities with long COVID. Today, PACVS is still not officially recognised as a disease. In contrast, long COVID was registered by health authorities in December 2021. Here, we address possible reasons for that discrepancy. We analyse whether common symptoms of PACVS have been registered by European pharmacovigilance as adverse vaccination reactions and which consequences have been drawn thereof. (i) PACVS is distinguished from normal vaccination reactions solely by prolonged duration. (ii) Symptom duration is poorly monitored by post-authorisation pharmacovigilance. (iii) PACVS-specific signals were faithfully recorded by pharmacovigilance systems but have not prompted appropriate reactions of health authorities. (iv) The most widely applied SARS-CoV-2 mRNA-vaccine has been modified after roll-out without renewed phase III evaluation; the modification has increased DNA contaminations suspected to extend the spectrum of adverse events. (v) Crossing of pharmacovigilance data with corresponding estimates of applied vaccine doses suggest a PACVS prevalence of 0.003% in the general population. In contrast, occupational surveillance studies suggest a PACVS prevalence of 0.9% in young and middle-aged persons. (a) Denial of official recognition of PACVS is unjustified. (b) PACVS seems to target preferentially young and middle-aged persons. (c) Without official disease recognition, access to public healthcare and welfare services is made difficult for PACVS-affected persons, which creates considerable socio-economic problems. (d) Without official disease recognition, development and evaluation of PACVS therapies is impaired.