There are readily available antibody tests that help determine if the human body has been exposed to the Sars-CoV-2 virus or exposed to a vaccine that generates antibodies to a subset of the actual virus (CDC Serology Testing). Based on many published scientific works having segregated antibodies from disease versus vaccines, it also appears feasible to determine if the body shows a reaction to the full virus, or a subset of the virus (reaction to a vaccine). This latter test is likely not readily available, but instead, available to medical researchers.

The above serology testing is based on detecting antibodies with specific properties that indicate their origin. The question I have is about having tissue samples tested, as opposed to blood or serum.

Is it feasible to have a tissue sample (a "biopsy") analyzed to check for the presence of Sars-CoV-2 spike protein? These proteins, produced by the human cellular machinery upon introduction of vaccine vector or by the disease itself are thought to be destroyed over time. To validate the speed and completeness of this destruction, is there a protocol to test a sample to ascertain the level of these proteins? If so, what researchers are doing this work?

Edit to add: The purpose of the test would be to validate the claim that the proteins generated by the vaccines do not persist in the human body.

  • What would be the purpose of such testing?
    – Carey Gregory
    Aug 31, 2021 at 14:31
  • "The purpose of the test would be to validate the claim that the proteins generated by the vaccines do not persist in the human body." No serious biologist would consider this a real concern. It sounds more like some kind of anti-vaxxer "concern". And "persist" for how long? It obviously persists for a while, or else you wouldn't get any antibodies. Aug 31, 2021 at 15:08
  • The question is not from a serious biologist perspective, nor an anti-vaxx perspective. The question was an attempt to discover human, in-vivo decay rates of the generated proteins from vaccination, just to validate the existing science associated with the decay. If it's a "dumb question" for serious biologists, then there we have it.
    – Dale
    Aug 31, 2021 at 15:43
  • 1
    If you want some estimates of spike protein lifetime, the Novavax vaccine studies are probably the best source since it doesn't use mRNA (or some viral vector) but directly the "subunit" spike protein. I'll see if I can dig up some number/study later on. Aug 31, 2021 at 15:44

2 Answers 2


It's unclear to me what tissue you expect to be sampled. SARS-CoV-2 is a respiratory virus and like similar viruses it's (differentially) diagnosed by "nasal" (more accurately: nasopharyngeal) swabs and PCR or at most by doing the same (PCR) on the more invasive (to obtain) BAL samples, which are more commonly used in pneumonia cases. (The latter samples are also used to detect bacterial co-infections etc.)

Actually, SARS-CoV-2 has some affinity for cells in the digestive tract as well, but while stool sampling can detect it, I haven't heard of it this method being very common, in practice. (As far as determining the aforementioned affinity, some duodenal biopsies were performed, but that would be way overkill/invasive for regular diagnostics.)

As for your question on the destruction of the spike protein from the vaccines... no that hasn't been tested at all in humans, as far as I know. During vaccine development, modified fluorescent proteins have been used in vitro to determine how the protein spreads and how long it lasts. (For some other vaccines, I do recall seeing full-mouse fluorescent images, but I'm not sure such studies have been for SARS-CoV-2 vaccines in particular, due to the speed of development during the pandemic.) For a state-of-the-art paper on fluorescence tracking of mRNA during delivery see e.g. https://pubs.acs.org/doi/10.1021/jacs.1c00014

Below is what a "kinetic biodistribution" study looks like. This one is for an experimental Chinese mRNA vaccine, using two different types on nanoparticles. (The point of the paper is to claim that their LPP is in some ways superior to "traditional" LNPs used in Western vaccines.)

enter image description here

The time-graph (e) is pretty badly rendered; there's larger version here, but from I can see, they've only tracked up to 240 hours, after which the mRNA was mostly gone (except maybe from the lungs), so they stopped.

These things are generally conducted for regulatory approval purposes, but not always published as papers in the academic press. For your purpose of knowing the trajectory of the spike protein rather than mRNA, a study like this on a protein subunit vaccine like Novavax's would be useful, but from their studies I know about, they haven't published something like the above.

  • So to be clear, in order for lifetimes of spike proteins to be measured, they would need to be of type that fluoresced, and since the sequence in the standard vaccines code for non-fluorescing type, there's not an easy way to identify these proteins in a tissue sample.
    – Dale
    Aug 31, 2021 at 15:00
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    @Dale: it's not clear to me for what purpose you want this measured (hence the snide-ish remark you've deleted in my answer). RNA decays and exogenous RNA is even attacked by the immune system instead of being translated, which is pretty hard to "fool" in that regard. Resulting spike proteins may be somewhat more stable decay-wise, but they also get attacked by the immune system. Aug 31, 2021 at 15:05

Yes, there is a way to test for presence of the spike protein in organ samples. This may not be possible in human biopsies / tissue samples with the standard vaccine, but it was done by Pfizer while testing BNT162, PF-07302048, as indicated in their own test data*. Done in rats (Wistar Han strain).

Mean total lipid concentration in rats over time, Pfizer Report 185350

The highest concentrations were found in: Injection site 165, Liver 24.3, Spleen 23.4, Adrenal glands 18.2, Ovaries 12.3, Bone marrow 3.77, Small intestine 1.47, Lymph (mesenteric) 1.37, Large intestine 1.34, Lung 1.09, Thyroid 1 µg lipid equivalent/g.

  • That graph measures/plots lipids not proteins; the former are the "shells" of the mRNA vaccines. (The graph is also not actually in the pdf you linked, as far as I can tell.) Sep 18, 2021 at 5:44
  • The graph you've posted does seem based on the table on "page 6" in pdf though...which in the 16th page in the pdf actually as it appears to be a concatenation of two different documents. Sep 18, 2021 at 5:52

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