How long does spike protein typically remain detectable after COVID-19 infection versus after mRNA or adenoviral vaccination?
Executive summary
Studies and reporting offer widely different timeframes for detectable SARS‑CoV‑2 spike protein after infection versus after vaccination: peer‑reviewed work from 2022 found spike detectable for about eight weeks after infection (available sources do not mention that exact 8‑week peer‑review citation), whereas recent preprints and non‑peer outlets report vaccine‑associated spike detection from months up to roughly 700–709 days in select cohorts — findings described in a 2025 Yale LISTEN preprint and repeated in media summaries [1] [2] [3]. Major outlets and experts interviewed stress uncertainty about frequency, clinical significance, and whether vaccine‑derived spike reflects persistent production vs. slow clearance of fragments [4] [5].
1. What the literature and reporting actually say about infection‑linked spike detection
Early, peer‑reviewed studies generally observed that viral proteins and viral RNA are detectable for weeks to a few months after acute SARS‑CoV‑2 infection, and many reviews treat post‑infection protein remnants as not unusual; Frontiers coverage and other scholarly pieces frame soluble S1 spike as implicated in post‑acute sequelae but do not assert years‑long persistence for most people [6] [7]. Available sources do not provide a single definitive, peer‑reviewed duration for spike after infection in every patient; rather, researchers report that soluble spike can play a role in PASC biology while emphasizing variability and remaining questions [6].
2. The Yale LISTEN preprint: long persistence reported in a selected cohort
Media coverage and some outlets highlight a Yale‑led LISTEN preprint that detected spike protein in some vaccinated people who lacked evidence of prior infection, with claims of detection “up to 700–709 days” after vaccination in that cohort [2] [3] [1]. The reporting makes clear the FINDINGS came from preprints or decentralized studies of people reporting post‑vaccine symptoms — not from broad population surveillance — and that the work had not been fully peer‑reviewed at the time of coverage [1] [4].
3. Conflicting measurements and smaller studies: months, not necessarily years, in other work
Other studies cited in available reporting find shorter but still substantial windows: one group detected the S1 portion of spike in circulating CD16+ monocytes up to 245 days after vaccination; a small clinical series reported vaccine‑associated spike in cerebral arteries at up to 17 months in select stroke cases [8]. These are narrower, specific findings from limited samples that reporters and fact‑checkers use to highlight heterogeneity in measurements [8].
4. Interpretation disputes and unresolved causal claims
Journalistic and fact‑check sources stress that detection of spike protein is not synonymous with active viral infection, nor does it by itself prove DNA integration or ongoing “endless production” of spike; such mechanistic claims were raised by commentators but are not established by the cited studies [4] [2]. Experts quoted in reporting note that protein fragments can linger and be cleared slowly and that vaccines also prime immune clearance — interpretations vary across sources [5].
5. Who was studied matters: cohort selection drives headlines
The Yale LISTEN work and similar reports focused on people with post‑vaccination syndrome or small clinical series, not representative population cohorts; media amplification sometimes omitted those caveats [1] [2]. Snopes and other fact‑checkers explicitly flagged that frequency, level and clinical significance of vaccine‑associated spike detection were unclear and that peer review was pending for key datasets [4].
6. Scientific and public‑health context: presence ≠ harm
Frontiers commentary and clinicians quoted in news pieces emphasize that detection of soluble spike or fragments can suggest biological activity worth studying, but does not by itself demonstrate that lingering spike causes disease across populations; clinical significance remains debated and unsettled in the cited sources [6] [5]. Some outlets and writers promote detox protocols or prognostic assertions, but science‑based critiques warn these are speculative and not established [9] [10].
7. Bottom line for readers weighing evidence
Available reports show that spike protein is often detectable for weeks to months after infection or vaccination, and a few targeted preprints and small studies report much longer detection in selected individuals — up to roughly 700–709 days in the Yale‑linked reporting — but those findings are from special cohorts or preprints and lack broad confirmation or settled clinical interpretation [2] [1] [8] [4]. Policymakers and clinicians quoted in coverage urge caution: detection alone does not prove harm, and larger, peer‑reviewed population studies are needed before revising safety conclusions [4] [5].
Limitations: this analysis uses only the provided sources; many primary peer‑reviewed studies and systematic reviews on spike persistence may exist beyond these links and are not included here (not found in current reporting).