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A selected view does not represent the real world of SARS-CoV-2 vaccination outcomes

Published:November 25, 2021DOI:https://doi.org/10.1016/j.cmi.2021.11.013

      Key words

      Letter to the Editor
      We read with interest the article by Shasha et al. about real world safety data for the Pfizer vaccine BNT162b2 in a large cohort of 394609 participants [
      • Shasha D.
      • Bareket R.
      • Sikron F.H.
      • Gertel O.
      • Tsamir J.
      • Dvir D.
      • Mossinson D.
      • Heymann A.D.
      • Zacay G.
      Real-world safety data for the Pfizer BNT162b2 SARS-CoV-2 vaccine, historical cohort study.
      ]. Four diagnoses, respectively symptoms were used as outcome parameters, Bell’s palsy, herpes zoster, Guillain-Barre syndrome (GBS), and numbness and tingling [
      • Shasha D.
      • Bareket R.
      • Sikron F.H.
      • Gertel O.
      • Tsamir J.
      • Dvir D.
      • Mossinson D.
      • Heymann A.D.
      • Zacay G.
      Real-world safety data for the Pfizer BNT162b2 SARS-CoV-2 vaccine, historical cohort study.
      ]. It was found that numbness and tingling occurred more frequently among vaccinees than in controls but not the other three outcome variables. [
      • Shasha D.
      • Bareket R.
      • Sikron F.H.
      • Gertel O.
      • Tsamir J.
      • Dvir D.
      • Mossinson D.
      • Heymann A.D.
      • Zacay G.
      Real-world safety data for the Pfizer BNT162b2 SARS-CoV-2 vaccine, historical cohort study.
      ]. It is the merit of this study, that at least a small spectrum of possible adverse reactions were addressed, but concerns remain.
      One limitation of the study is that the endpoints were identified by visit diagnoses. The authors themselve admit that this method of data acquisition might lead to “partial or inaccurate” diagnoses [
      • Shasha D.
      • Bareket R.
      • Sikron F.H.
      • Gertel O.
      • Tsamir J.
      • Dvir D.
      • Mossinson D.
      • Heymann A.D.
      • Zacay G.
      Real-world safety data for the Pfizer BNT162b2 SARS-CoV-2 vaccine, historical cohort study.
      ]. Diagnosing GBS, for example, requires application of the Brighton criteria. Application of the Brighton criteria implies that patients with suspected GBS undergo cerebro-spinal fluid (CSF) investigations and nerve conduction studies (NCSs) in addition to history and clinical exam. It would be interesting to know if the patient with GBS in the investigated cohort fulfilled the Brighton criteria or not.
      Another limitation is that the cause of sensory symptoms was not sufficiently explored, which admittedly, is inherent to the retrospective design. Anyhow, attributing sensory symptoms of the face to anxiety is unsupported by the presented data as various differentials were not excluded. Since sensory symptoms (numbness and tingling) were “mainly on one side of the face”, small fiber neuropathy (SFN) is rather unlikely the cause of these symptoms given the fact that SFN usually manifests in the feet and the hands [
      • Raasing L.R.M.
      • Vogels O.J.M.
      • Veltkamp M.
      • van Swol C.F.P.
      • Grutters J.C.
      Current View of Diagnosing Small Fiber Neuropathy.
      ]. Attributing sensory symptoms of the face to processing of reports in mass media about a suspected association between SARS-CoV-2 vaccinations and facial palsy is misleading as sensory abnormalities of the face rather suggest affection of the trigeminal than the facial nerve. Since mono- or polyneuritis cranialis is a confirmed complication of SARS-CoV-2 infections [
      • Finsterer J.
      • Scorza F.A.
      • Scorza C.
      • Fiorini A.
      COVID-19 associated cranial nerve neuropathy: A systematic review.
      ] and since SARS-CoV-2 vaccinations imitate the infection, it is warranted that mono-neuritis of a clinically affected cranial nerve is appropriately excluded. Sensory disturbances in the face can be, for example, the initial manifestation of a zoster infection.
      A further limitation is that 41% of the eligible vaccinees were excluded for reasons of matching. Though inclusion of these 41% might bias the evaluation, valuable information could be achieved as well. Particularly, it would be interesting to know if comparison of the entire cohort of eligible vaccines with the control cohort results in conclusions at variance from those reported. Matching for the number of comorbidities but not the type of comorbidity is a bias as well.
      Selection of only four outcome parameters “of concern” was established by identifying outcomes by clinical visits. However, more than four outcome parameters can be assessed upon clinical visits. Considering only the neurological side effects of SARS-CoV-2 vaccinations, the spectrum of adverse reactions is much broader, including headache, myalgia, venous sinus thrombosis (VST), transverse myelitis, SFN, immune encephalitis, and others in addition to GBS and facial palsy. Headache is by far the most prevalent of the neurological side effects and can be easily assessed by clinical visits as well as myalgia. We should know why only four outcome measures were selected although the MHMO database offered more options.
      The term Bell’s palsy is inaccurate. Bell’s palsy stands for facial nerve palsy of undetermined cause. If facial palsy is attributed to a reaction against the vaccination, the term Bell’s palsy should be avoided.
      Overall, the interesting study has limitations which challenge the results and their interpretation. Real world data rather indicate that the spectrum of side effects to any of the commercially available SARS-CoV-2 vaccinations is broader than anticipated, underreported, and played down. Side effects need to be thoroughly elaborated to draw more real pictures than those frequently sold. Real world is more unsafe than its propagated image.

      Ethical approval and consent to participate

      not applicable.

      Consent for Publication

      not applicable.

      Availability of data and material

      all data reported are available from the corresponding author.

      Competing interests

      none.

      Funding

      none received.

      Author contribution

      JF: design, literature search, discussion, first draft, critical comments, FS: literature search, discussion, critical comments, final approval.

      Acknowledgements

      none.

      References

        • Shasha D.
        • Bareket R.
        • Sikron F.H.
        • Gertel O.
        • Tsamir J.
        • Dvir D.
        • Mossinson D.
        • Heymann A.D.
        • Zacay G.
        Real-world safety data for the Pfizer BNT162b2 SARS-CoV-2 vaccine, historical cohort study.
        Clin Microbiol Infect. 2021 Sep 27; (S1198-743X(21)00538-3)https://doi.org/10.1016/j.cmi.2021.09.018
        • Raasing L.R.M.
        • Vogels O.J.M.
        • Veltkamp M.
        • van Swol C.F.P.
        • Grutters J.C.
        Current View of Diagnosing Small Fiber Neuropathy.
        J Neuromuscul Dis. 2021; 8: 185-207https://doi.org/10.3233/JND-200490
        • Finsterer J.
        • Scorza F.A.
        • Scorza C.
        • Fiorini A.
        COVID-19 associated cranial nerve neuropathy: A systematic review.
        Bosn J Basic Med Sci. 2021 Aug 11; https://doi.org/10.17305/bjbms.2021.6341

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