Abstract This paper sets out an alternative theory of why COVID-19 struck the elderly so disproportionately hard — an account that departs from the official narrative of a single, wholly novel viral disease. Its genesis was not theoretical. It began as an intuition, drawn from an unexpected epidemiological pattern we observed in a Spanish healthcare sector in 2020; that pattern was later partially reproduced, at attenuated magnitude, at population scale and after extensive statistical adjustment, in a large peer-reviewed Catalan cohort; and what began as a hunch about a shared vaccine excipient has since gained independent mechanistic support from a growing body of published research on anti-PEG antibodies, most notably direct evidence of their cross-reactivity with human self-antigens. We present this convergence — an original field observation, independent epidemiological support in the same direction, and emerging mechanistic evidence — as a coherent alternative theory, not as a speculative aside to the official account. We argue that severe COVID-19 in the elderly was not the unprecedented disease entity it was widely taken to be, but essentially another instance of a recurring winter phenomenon that hospital physicians have long called "complicated flu" — a broad clinical label historically applied to severe respiratory decompensation in vulnerable patients during the winter respiratory season, regardless of which of several circulating microbes was the immediate trigger. The complication in these cases is not, in our view, the infecting agent itself, however named, but a pre-existing, immune-mediated iatrogenia: anti-PEG antibodies, generated by prior administration of polysorbate-containing vaccines and other polyethoxylated drugs, primed to react against phospholipid surfaces exposed once a winter respiratory infection — SARS-CoV-2 among them — causes local tissue damage. This document presents the field observation that first motivated our subsequent, more general work on excipient-mediated iatrogenic autoimmunity (1, 2). In 2019–2020, an epidemiological review of COVID-19 deaths in a Spanish healthcare sector found a marked, statistically significant excess of mortality among individuals who had received a polysorbate-adjuvanted influenza vaccine weeks earlier. That observation was publicly dismissed at the time by the Spanish Ministry of Health, on grounds we revisit in Section 2, without a competing analysis of the same data. Two years later, a large, independently conducted, adjusted Catalan cohort study reported a modest but statistically significant residual association in the same direction. That observation — presented here with corrected statistics, alongside this later, independent support — is, in our reading, the moment this underlying iatrogenic pattern became visible: a novel virus prompted scrutiny that routine winter mortality, absorbed for decades into the unexamined category of "gripe complicada", had never received. The mechanism we propose — anti-PEG IgM recognizing phospholipid surfaces exposed by tissue damage — has some direct experimental support (Section 4), though obtained with animal-raised rather than natural human antibodies; we treat this as an active, testable hypothesis, not a settled fact, and Section 8 states plainly what remains to be shown and what would falsify it. A fuller mechanistic development of the general anti-PEG/polyethoxylated-excipient framework is available in a companion document (2), to which this preprint is explicitly subordinate for mechanistic detail.
Añaños et al. (Fri,) studied this question.