Vaccination Status and Number of Vaccine Doses Are Independently Associated with the PaO2/FiO2 Ratio on Admission in Hospitalized COVID-19 Patients

Elisabetta Zinellu; Angelo Zinellu; Michela Merella; Arduino A Mangoni; Maria Carmina Pau; Sara S Fois; Alessandro G Fois; Ciriaco Carru; Pietro Pirina

doi:10.3390/vaccines10091424

Vaccination Status and Number of Vaccine Doses Are Independently Associated with the PaO₂/FiO₂ Ratio on Admission in Hospitalized COVID-19 Patients

Vaccines (Basel). 2022 Aug 29;10(9):1424. doi: 10.3390/vaccines10091424.

Authors

Elisabetta Zinellu¹, Angelo Zinellu², Michela Merella³, Arduino A Mangoni^{4

5}, Maria Carmina Pau³, Sara S Fois³, Alessandro G Fois^{1

3}, Ciriaco Carru², Pietro Pirina^{1

3}

Affiliations

¹ Clinical and Interventional Pneumology, University Hospital of Sassari (AOU), 07100 Sassari, Italy.
² Department of Biomedical Sciences, University of Sassari, 07100 Sassari, Italy.
³ Department of Medicine, Surgery and Pharmacy, University of Sassari, 07100 Sassari, Italy.
⁴ Discipline of Clinical Pharmacology, College of Medicine and Public Health, Flinders University, Bedford Park, SA 5042, Australia.
⁵ Department of Clinical Pharmacology, Flinders Medical Centre, Southern Adelaide Local Health Network, Bedford Park, SA 5042, Australia.

Abstract

Introduction: Coronavirus Disease-19 (COVID-19) vaccines reduce the risk of severe disease and mortality. However, the association between vaccination status and number of doses and the PaO₂/FiO₂ ratio, a clinical measure of hypoxemia associated with an increased risk of intensive care treatment and mortality, has not been investigated.

Methods: We retrospectively assessed a consecutive series of 116 patients admitted to hospital with a primary diagnosis of COVID-19 between January and April 2022. Demographic, clinical, and laboratory data were collected within 24 h from admission.

Results: There was a significant positive relationship between the number of vaccine doses and the PaO₂/FiO₂ ratio (r = 0.223, p = 0.012). This association remained significant after adjusting for confounders. Vaccinated patients had significantly higher PaO₂/FiO₂ ratios than the unvaccinated (median: 250; IQR: 195-309 vs. 200; IQR: 156-257, p = 0.013).

Conclusion: These results highlight the importance of the number of vaccine doses received in reducing the degree of hypoxia on admission in hospitalized COVID-19 patients.

Keywords: COVID-19; P/F ratio; hospitalized patients; vaccine doses received.

Grants and funding

This research received no external funding.