EFFECT OF FULL VACCINATION AND POST-COVID OLFACTORY DYSFUNCTION IN RECOVERED COVID-19 PATIENT. A RETROSPECTIVE LONGITUDINAL STUDY WITH PROPENSITY MATCHING

  1. Bumi Herman
  2. Pramon Viwattanakulvanid
  3. Azhar Dzulhadj
  4. Aye Chan Oo
  5. Karina Patricia
  6. Sathirakorn Pongpanich

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Abstract

Symptoms after COVID-19 infection affect the quality of life of its survivor especially to the special senses including olfactory function. It is important to prevent the disability at an earlier stage. Vaccination as key prevention has been proven to be effective in reducing symptomatic disease and severity. However, the effects of vaccination on post COVID symptoms have not been evaluated. This study aimed to evaluate the possible protection of full vaccination and the occurrence of post-COVID olfactory dysfunction, specifically anosmia and hyposmia in patients who were diagnosed with COVID19.

Method

A longitudinal analysis using the retrospective cohort of the Indonesian patient-based Post-COVID survey collected from July 2021 until December 2021, involving COVID-19 Patients confirmed by RT-PCR and/or Antigen test. Variables including demography, comorbidities, health behavior, type of vaccine, symptoms, and treatment were collected through an online questionnaire based on the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS). Participants were matched (1:1) using propensity matching score into two exposure statuses, infected 1)>14 days of full vaccination and 2)<14 days or incomplete or unvaccinated. The olfactory dysfunction was assessed two weeks and four weeks after negative conversion with PCR using a self-measured olfactory questionnaire (MOQ). The Generalized Estimating Equation (GEE) was performed to assess the effect of full vaccination on post-COVID olfactory dysfunction. The Receiver Operating Characteristic determined the sensitivity and specificity of the cutoff value of the days from fully vaccinated to diagnosis and the olfactory dysfunction.

Results

A total of 442 participants were extracted from the cohort and inoculated with the inactivated viral vaccine (99.5%). The prevalence of olfactory dysfunction in two weeks was 9.95% and 5.43% after four weeks. Adjusted by other variables, people who were infected >14 days after being fully vaccinated had a 69% (adjusted OR 0.31 95% CI 0.102-0.941) probability of developing olfactory dysfunction. Longer days of fully vaccinated to infection associated with increased risk (adjusted OR 1.012 95% CI 1.002-1.022 p-value 0.015). A cut-off of 88 days of full vaccination-to-diagnosis duration has Area Under Curve (AUC) of 0.693 (p=0.002), the sensitivity of 73.9%, and specificity of 63.3% in differentiating the olfactory dysfunction event in two weeks after COVID with a crude odds ratio of 4.852 (95% CI 1.831-12.855 p=0.001)

Conclusion

After 14 days of full vaccination, the protective effect could reduce the chance of post-COVID olfactory dysfunction although a longer full vaccination-to-diagnosis duration increases the risk. It is important to consider a booster shot starting from 89 days after the last dose in those who received the inactivated viral regimen.

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    SciScore for 10.1101/2022.01.10.22269007: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: Ethical Approval: This study was approved by The Research Ethics Review Committee for Research Involving Human Research Participants, Faculty of Medicine Hasanuddin University (Approval number of full review UH21110687).
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power AnalysisThe sample size is calculated considering 5% type I error, 95% power, with equal sample size between two groups and two repeated measures, assuming the correlation between measurements is 0.5.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    This is the reason why this study conducted a self-assessment for olfactory dysfunction, which addressed as a limitation. The Quick Olfactory Sniffin’s Stick test is one of the objective assessments to confirm the olfactory dysfunction using certain strong scents put at the distance of 1-2 cm from nostrils and it has a good performance in identifying the olfactory dysfunction in COVID 19 patients(28). But the Self-MOQ underwent validation through Sniffin’s stick test and shows a good discriminant ability(25). Missing at random in outcome assessment was likely occurred as the entire questionnaire is long and the proposed analysis using GEE will introduce bias if the cases with missing data are included. Analysis and Effect of Vaccination: Aside from occupation, this study also considers island as important demographic factors due to distribution and procurement of vaccine which affect the allocation of exposure status, and the distribution of dominant SARS-Cov2 strains wherein Java during the second wave, Delta variant was the most prevalent strain, and small percentage Alpha and Beta were found in Sumatera and Java(29). Mutation of SARS-Cov2 leads to different clinical manifestations(30) due to different abilities to attach to the host cell or the ability to escape from the immune response. Furthermore, Indonesia experience two COVID-19 waves where the first wave was dominated by wild type variant followed by Alpha and Beta. Several studies indicate the decremental vaccine ef...

    Results from TrialIdentifier: We found the following clinical trial numbers in your paper:

    IdentifierStatusTitle
    NCT05060562RecruitingPost Coronavirus Disease (COVID-19) Syndrome Indonesian Popu…

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

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  2. Version published to 10.1101/2022.01.10.22269007v1 on medRxiv