Old Age is an Independent Risk Factor for Pneumonia Development in Patients with SARS-CoV-2 Omicron Variant Infection and a History of Inactivated Vaccine Injection

Xuecheng Tong; Zeyu Huang; Xiujun Zhang; Guocan Si; Huifen Lu; Wei Zhang; Yuan Xue; Weibin Xie

doi:10.2147/IDR.S380005

Old Age is an Independent Risk Factor for Pneumonia Development in Patients with SARS-CoV-2 Omicron Variant Infection and a History of Inactivated Vaccine Injection

Infect Drug Resist. 2022 Sep 21:15:5567-5573. doi: 10.2147/IDR.S380005. eCollection 2022.

Authors

Xuecheng Tong^{1

2}, Zeyu Huang¹, Xiujun Zhang^{1

2}, Guocan Si², Huifen Lu², Wei Zhang², Yuan Xue^{1

2}, Weibin Xie³

Affiliations

¹ Institute of Hepatology, the Third People's Hospital of Changzhou, Changzhou, People's Republic of China.
² Department of Infectious Diseases, the Third People's Hospital of Changzhou, Changzhou, People's Republic of China.
³ Department of Anesthesiology, the Third People's Hospital of Changzhou, Changzhou, People's Republic of China.

Abstract

Objective: Analyzing the risk factors for pneumonia development in breakthrough cases with a history of inactivated vaccine injection is important. The present study aimed to investigate the risk factors for pneumonia development during Omicron variant infection.

Design and methods: The clinical data were retrospectively collected from 187 patients who previously received inactivated vaccine and were infected by the Omicron variant.

Results: Among the 187 patients, 73 had 2 doses of inactivated vaccine injection and the remaining 114 had 3 doses; 19 patients had pneumonia at admission. The univariate logistic analysis showed that age, baseline platelet count, D-dimer level, and CD8⁺ T lymphocyte count were associated with pneumonia development at admission. The multivariate analysis showed that only age was the independent risk factor for pneumonia development (odds ratio = 1.046, 95% confidence interval: 1.003-1.091, P = 0.04). With an optimal cutoff value of 46, 4.4% (4/91) patients in the age <46 years group and 15.63% (15/96) patients in the age ≥46 years group had pneumonia (χ ² = 6.454, P = 0.01). Moreover, age negatively correlated with CD8⁺ T cell count, B cell count, and albumin and uric acid levels (all P < 0.01), while age positively correlated with the glucose level (P < 0.01).

Conclusion: Old age was the only independent risk factor for pneumonia development in patients with Omicron variant infection and a history of inactivated vaccine injection.

Keywords: COVID-19; Omicron; SARS-CoV-2; glucose; pneumonia.

Grants and funding

This study was supported by the 333 High-level Talents Project of Jiangsu Province (LGY2020032), the Science and Technology Project of Changzhou (CJ20200057), Qingmiao Talents Cultivation Project of Changzhou Health Commission (CZQM2020089), Project of High-quality Education Resources of Nanjing Medical University (2021H049).