2023年 · 第03卷第01期

The pandemic of coronavirus disease 2019 is "not over," in fact, the "dynamic clearing" policy for SARS-CoV-2 control and prevention in China has been firmly enforced. This study aimed to analyze the clinical symptoms and dynamic viral RNA changes in 2021 at Guangzhou Eighth People’s Hospital. This study showed that 31.4% of the patients (695/2212) tested negative for viral RNA from admission to the final release from quarantine. Of all negative cases, 86.5% (601/695) remained in the hospital for no more than 5 days and were asymptomatic or mild. Among the remaining 402 patients who stayed for no more than 5 days, 76.4% (307/402) were viral RNA retest positive during the isolation stage. However, 96.4% of the peak viral RNA (296/307) was over Ct = 33 cycles during the isolation stage.

We presented a case of a 32-week pregnant woman with coronavirus disease 2019 and tuberculosis delivering a healthy baby. She was treated with antituberculosis and other symptomatic treatments, and the nucleic acid test; the sputum tuberculosis bacterial smear turned negative; and the symptoms were significantly relieved.

Background: Hand, foot, and mouth disease caused by enterovirus 71 (EV71) infection is prevalent in the Asia-Pacific region in recent years. Currently, no drug is available for the prevention and treatment of EV71 infection. IMB-0523, a N-phenylbenzamide derivative, inhibits hepatitis B virus replication by upregulating the expression of APOBEC3G. In the present study, the effect of IMB-0523 on EV71 replication and related mechanism were investigated. Methods: The cytotoxicity of IMB-0523 was determined by cell counting kit. Quantitative real-time polymerase chain reaction and Western blot assay were used to detect the effect of IMB-0523 on EV71 replication and related mechanism. Cytopathic effect assay was used to investigate the effect of IMB-0523 on different EV71 strains, coxsackievirus A16, and coxsackieviruses of group B. Results: The results showed that IMB-0523 could dose-dependently inhibit EV71 replication. Preliminary mechanism studies showed that IMB-0523 could activate STAT3 signaling to upregulate the expression of interferon-stimulated genes to play an antiviral role. In addition, IMB-0523 inhibited the replication of different EV71 strains, coxsackievirus A16, and coxsackieviruses of group B. Conclusions: IMB-0523 inhibits EV71 replication by activating the STAT3 signaling pathway to upregulate interferon-stimulated gene expression. IMB-0523 has broad-spectrum antiviral potential and may be used as a lead compound for the development of broad spectrum antiviral drugs.

Background: Whether methylprednisolone therapy can reduce the mortality rate of patients with severe coronavirus disease 2019 (COVID-19) remains controversial, and its effects on the length of hospital stay and virus shedding time are also unknown. This retrospective study investigates the previous issues to provide more evidence for methylprednisolone treatment in severe COVID-19. Methods: This retrospective study included 563 of 4827 patients with confirmed COVID-19 admitted to Wuhan Huoshenshan Hospital or Wuhan Guanggu Hospital between February 3, 2020 and March 30, 2020 who met the screening criteria. The participants’ epidemiological and demographic data, comorbidities, laboratory test results, treatments, outcomes, and vital clinical time points were extracted from electronic medical records. The primary outcome was in-hospital death, and the secondary outcomes were 2 clinical courses: length from admission to viral clearance and discharge. Univariate and multivariate logistic or linear regression analyses were used to assess the role of methylprednisolone in different outcomes. Propensity score matching was performed to control for confounding factors. Results: Of the 563 patients who met the screening criteria and were included in the subsequent analysis, 138 were included in the methylprednisolone group and 425 in the nonmethylprednisolone group. The in-hospital death rate between the methylprednisolone and nonmethylprednisolone groups showed a significant difference (23.91% vs. 1.65%, P < 0.001), which was maintained after propensity score matching (13.98% vs. 5.38%, P = 0.048). However, univariate logistic analysis in the matched groups showed that methylprednisolone treatment (odds ratio [OR], 5.242; 95% confidence interval [CI], 0.802 to 34.246; P = 0.084) was not a risk factor for in-hospital death in severe patients. Further multivariate logistic regression analysis found comorbidities (OR, 3.327; 95% CI, 1.702 to 6.501; P < 0.001), lower lymphocyte count (OR, 0.076; 95% CI, 0.012 to 0.461; P = 0.005), higher lactate dehydrogenase (LDH) levels (OR, 1.008; 95% CI, 1.003 to 1.013; P = 0.002), and anticoagulation therapy (OR, 11.187; 95% CI, 2.459 to 50.900; P = 0.002) were associated with in-hospital mortality. Multivariate linear regression analysis in the matched groups showed that methylprednisolone treatment was not a risk factor for a prolonged duration from admission to viral clearance (β Value 0.081; 95% CI, -1.012 to 3.657; P = 0.265) or discharge (β Value 0.114; 95% CI, -0.723 to 6.408; P = 0.117). D-dimer (β Value, 0.144; 95% CI, 0.012 to 0.817; P = 0.044), LDH (β Value 0.260; 95% CI, 0.010 to 0.034; P < 0.001), and antiviral therapy (β Value 0.220; 95% CI, 1.373 to 6.263; P = 0.002) were associated with a longer length from admission to viral clearance. The lymphocyte count (β Value -0.206; 95% CI, -6.248 to -1.197; P = 0.004), LDH (β Value 0.231; 95% CI, 0.012 to 0.048; P = 0.001), antiviral therapy (β Value 0.143; 95% CI, 0.058 to 7.497; P = 0.047), and antibacterial therapy (β Value 0.152; 95% CI, 0.133 to 8.154; P = 0.043) were associated with a longer hospitalization duration from admission to discharge. Further stratified analysis revealed that the low daily dose group (≤60 mg/d) and the low total dose group (≤200 mg) had shorter duration from admission to viral clearance (Z=-2.362, P = 0.018; Z=-2.010, P = 0.044) and a shorter hospital stay (Z=-2.735, P = 0.006; Z=-3.858, P < 0.001). Conclusions: In patients with severe COVID-19, methylprednisolone is safe and does not prolong the duration from admission to viral clearance or discharge. Low-dose, short-term methylprednisolone treatment may be more beneficial in shortening the disease course.

Background: The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has greatly threatened public health. Recent studies have revealed that the spike receptor-binding domain (RBD) of SARS-CoV-2 is a potent target for vaccine development. However, adjuvants are usually required to strengthen the immunogenicity of recombinant antigens. Different types of adjuvants can elicit different immune responses. Methods: We developed an RBD recombinant protein vaccine with a polyriboinosinic acid-polyribocytidylic acid [poly(I:C)] adjuvant to evoke a strong immune response. The delivery of poly(I:C) was optimized in two steps. First, poly(I:C) was complexed with a cationic polymer, poly-L-lysine (PLL), to form poly(I:C)-PLL, a polyplex core. Thereafter, it was loaded into five different lipid shells (group II, III-1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC], III-1,2-dioleoyl-sn-glycero-3-phosphoethanolamine [DOPE], IV-DOPE, and IV-DSPC). We performed an enzyme-linked immunosorbent assay and enzyme-linked immunosorbent spot assay to compare the ability of the five lipopolyplex adjuvants to enhance the immunogenicity of the SARS-CoV-2 RBD protein, including humoral and cellular immune responses. Finally, the adjuvant with the highest immunogenicity was selected to verify the protective immunity of the vaccine through animal challenge experiments. Results: Recombinant RBD protein has low immunogenicity. The different adjuvants we developed enhanced the immunogenicity of the RBD protein in different ways. Among the lipopolyplexes, those containing DOPE (III-DOPE and IV-DOPE) elicited RBD-specific immunoglobulin G antibody responses, and adjuvants with four components elicited better RBD-specific immunoglobulin G antibody responses than those containing three components (P < 0.05). The IC50 and IC90 titers indicated that the IV-DOPE lipopolyplex had the greatest neutralization ability, with IC50 titers of 1/117,490. Furthermore, in the challenge study, IV-DOPE lipopolyplex protected mice from SARS-CoV-2 infection. On the fourth day after infection, the average animal body weights were reduced by 18.56% (24.164 ± 0.665 g vs. 19.678 ± 0.455 g) and 0.06% (24.249 ± 0.683 g vs. 24.235 ± 0.681 g) in the MOCK and vaccine groups, respectively. In addition, the relative expression of viral RNA in the vaccinated group was significantly lower than that in the MOCK group (P < 0.05). Interstitial inflammatory cell infiltration was observed in the MOCK group, whereas no obvious damage was observed in the vaccinated group. Conclusions: The IV-DOPE-adjuvanted SARS-CoV-2 recombinant RBD protein vaccine efficiently protected mice from SARS-CoV-2 in the animal challenge study. Therefore, IV-DOPE is considered an exceptional adjuvant for SARS-CoV-2 recombinant RBD protein-based vaccines and has the potential to be further developed into a SARS-CoV-2 recombinant RBD protein-based vaccine.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a tremendous burden on public health and world economies. An efficient host immune response to acute SARS-CoV-2 infection requires rapid and early activation of the innate immune system. Natural killer (NK) cells represent a critical component of the innate immunity. Here, the appearance of CD56-CD16+ NK cells and unconventional CD56dim CD16neg NK cells during the course of SARS-CoV-2 infection, and the phenotype and effector functions of NK cells during SARS-CoV-2 infection were summarized. The involvement of the dysregulated NK cells in the immunopathogenesis of the coronavirus disease 2019 (COVID-19) and clinical trials of adoptive NK cell-based therapies against COVID-19 were also discussed.