Vaccination reduces viral load and accelerates viral clearance in SARS-CoV-2 Delta variant-infected patients.

OBJECTIVE: The purpose of this study was to investigate vaccine effectiveness in relieving symptoms in patients with the SARS-CoV-2 delta (B.1.617.2) variant. METHODS: In this retrospective study, 31 patients did not receive any vaccine (non-vaccination, NV), 21 patients received 1-dose of inactivated vaccine (one-dose vaccination, OV), and 60 patients received at least 2-dose inactivated vaccine (two-dose vaccination, TV). The baseline data, clinical outcomes and vaccination information were collected and analyzed. RESULTS: Patients in the OV group were younger than those in the other two groups (p = 0.001), but there was no significant difference in any of the other baseline data among the three groups. The TV group showed higher IgG antibody levels and cycle threshold values of SARS-CoV-2 than the NV and OV groups (p < 0.01), and time to peak viral load was shorter in the TV group (3.5 ± 2.3 d) than in the NV (4.8 ± 2.8 d) and OV groups (4.8 ± 2.9 d, p = 0.03). The patients in the TV group (18%) showed a higher recovery rate without drug therapy (p < 0.001). Viral clearance time and hospital stay were significantly shorter in the TV group than in the NV and OV groups (p < 0.01), and there were no significant differences in these parameters between the OV and NV groups, but IgG values were higher in the OV group (p = 0.025). No severe complications occurred in this study. CONCLUSIONS: Our results suggest that 2-dose vaccination can reduce viral load and accelerate viral clearance in patients with the delta variant and enhance the protection afforded by IgG antibodies in vivo.Key MessagesIn this study, our results shows that two-dose vaccination can reduce viral loads and accelerate viral clearance, and two-dose vaccination enhance the protection of IgG antibodies in vivo; however, one-dose vaccination did not confer protective effectiveness.

A comparison of the protective effect of vaccination and clinical features between the SARS-CoV-2 wild-type strain and Delta (B.1.617.2) variant

Introduction This study aimed to investigate the clinical features and vaccine effectiveness of patients with the SARS-CoV-2 wild-type strain and the Delta variant. Methods We retrospectively evaluated patients with the SARS-CoV-2 wild-type strain and the Delta variant. Results The Delta-variant group showed a higher infection rate in minors, who had higher incidence of anosmia or dysgeusia and shorter incubation period. Unvaccinated patients had a 15.59-fold higher risk of severe classification than vaccinated patients. The viral clearance time was significantly shorter in the Delta-variant group. Conclusions The Delta-variant group show higher transmissibility, and vaccination reduces the incidence of severe classification and promotes viral clearance.

The preliminary comparative results between Covid-19 and non-Covid-19 patients in Western China.

BACKGROUND: This study aims to investigate the comparative clinical characteristics of Covid-19 and non-Covid-19 patients. METHODS: Fifteen Covid-19 and 93 non-Covid-19 patients were included in RNA testing. All epidemiological and clinical data were collected and analyzed, and then comparative results were carried out. RESULTS: Covid-19 patients were older (46.40 ± 18.21 years vs 34.43 ± 18.80 years) and had a higher body weight (70.27 ± 10.67 kg vs 60.54 ± 12.33 kg, P < 0.05). The main symptoms that were similar between Covid-19 and non-Covid-19 patients, and Covid-19 patients showed a lower incidence of sputum production (6.67% vs 45.16%, P < 0.01) and a lower white-cell count (4.83 × 109/L vs 7.43 × 109/L) and lymphocyte count (0.90 × 109/L vs 1.57 × 109/L, P < 0.01). Although there were no differences, C-reactive protein and interleukin-6 were elevated in Covid-19 patients. The sensitivity and negative predictive value of CT images were 0.87 and 0.97, respectively. Covid-19 patients showed a higher contact history of Wuhan residents (80% vs 30.11%) and higher familial clustering (53.33% vs 8.60%, P < 0.001). Covid-19 patients showed a higher major adverse events (ARDS, 13.33%; death, 6.67%; P < 0.05). CONCLUSION: Our results suggested that Covid-19patients had a significant history of exposure and familial clustering and a higher rate of severe status; biochemical indicators showed lymphocyte depletion.

The preliminary comparative results between Covid-19 and non-Covid-19 patients in Western China (preprint)

Background: This study aims to investigate the comparative clinical characteristics of Covid-19 and non-Covid-19 patients.Methods: Fifteen Covid-19 and 93 non-Covid-19 patients were included in RNA testing. All epidemiological and clinical data were collected and analyzed, and then comparative results were carried out.Results: Covid-19 patients were older (46.40±18.21 years vs 34.43±18.80 years) and hada higher body weight (70.27±10.67 kg vs 60.54±12.33 kg, P<0.05). The main symptoms that were similar between Covid-19 and non-Covid-19 patients, and Covid-19 patients showed a lower incidence of sputum production (6.67% vs 45.16%, P<0.01) and a lower white-cell count (4.83×109/L vs 7.43×109/L) and lymphocyte count (0.90×109/L vs 1.57×109/L) (P<0.01). Although there were no differences, C-reactive protein and interleukin-6 were elevated in Covid-19 patients. The sensitivity and negative predictive value of CT images were 0.87 and 0.97, respectively. Covid-19 patients showed a higher contact history of Wuhan residents (80% vs 30.11%) and higher familial clustering (53.33% vs 8.60%, P<0.001). Covid-19 patients showed a higher major adverse events (ARDS, 13.33%; death, 6.67%; P<0.05).Conclusion: Our results suggested that Covid-19 patients had a significant history of exposure and familial clustering and a higher rate of severe status; biochemical indicators showed lymphocyte depletion.