Inactivated vaccines prevent severe COVID-19 in patients infected with the Delta variant: A comparative study of the Delta and Alpha variants from China.

The Delta variant has gradually replaced the Alpha variant as the major strain of SARS-COV-2 infection worldwide. We extracted the clinical characteristics and outcomes information about 381 hospitalized patients infected with Delta variant and compared them with 856 patients diagnosed with Alpha variant infection in Zhejiang Province. The majority (85.3%) of patients infected with the Delta variant had received inactivated vaccine. The patients' condition was generally mild. Most of them were mild (35.7%) and common (62.7%) types. Only six patients (1.5%) were severe/critical types. During the follow-up period, patients infected with the Delta variant had longer hospital stays than the Alpha variant (24 [21-26] vs. 18 [14-24], p < 0.001). In addition, the unvaccinated patients infected with the Delta variant had a higher proportion of severe/critical cases than vaccinated patients (11.11% vs. 0.92%, p = 0.024) and a higher usage rate of glucocorticoids (38.89 vs. 14.77%, p = 0.017) and antibiotics (55.56% vs. 32.31%, p = 0.042) during hospitalization. The vaccine's efficacy against severe COVID-19 did not diminish over time for patients who received two doses of the inactivated vaccine. The disease types and clinical manifestations were generally mild in patients infected with the Delta variant, possibly associated with widespread vaccination with inactivated vaccines in China.

High body mass index is a significant risk factor for the progression and prognosis of imported COVID-19: a multicenter, retrospective cohort study.

BACKGROUND: Coronavirus disease 2019(COVID-19) has spread worldwide. The present study aimed to characterize the clinical features and outcomes of imported COVID-19 patients with high body mass index (BMI) and the independent association of BMI with disease severity. METHODS: In this retrospective cohort study, 455 imported COVID-19 patients were admitted and discharged in Zhejiang province by February 28, 2020. Epidemiological, demographic, clinical, laboratory, radiological, treatment, and outcome data were collected, analyzed and compared between patients with BMI ≥ 24and < 24. RESULTS: A total of 268 patients had BMI < 24, and 187 patients had BMI ≥ 24. Those with high BMI were mostly men, had a smoking history, fever, cough, and sputum than those with BMI < 24. A large number of patients with BMI ≥ 24 were diagnosed as severe/critical types. Some biochemical indicators were significantly elevated in patients with BMI ≥ 24. Also, acute liver injury was the most common complication in these patients. The median days from illness onset to severe acute respiratory syndrome coronavirus 2 detection, duration of hospitalization, and days from illness onset to discharge were significantly longer in patients with BMI ≥ 24 than those with BMI < 24. High BMI, exposure to Wuhan, any coexisting medical condition, high temperature, C-reactive protein (CRP), and increased lactate dehydrogenase (LDH) were independent risk factors for severe/critical COVID-19. After adjusting for age, sex and above factors, BMI was still independently associated with progression to severe/critical illness (P = 0.0040). Hemoglobin, alanine aminotransferase (ALT), CRP, and serum creatinine (Scr) were independent risk factors associated with high BMI. CONCLUSIONS: Contrasted with the imported COVID-19 patients with BMI < 24, high proportion of COVID-19 patients with BMI ≥ 24 in our study, especially those with elevated CRP and LDH, developed to severe type, with longer hospitalization duration and anti-virus course. Thus, high BMI is a risk factor for the progression and prognosis of imported COVID-19.