DNA vaccine prime and replicating vaccinia vaccine boost induce robust humoral and cellular immune responses against MERS-CoV in mice.

As of December 2022, 2603 laboratory-identified Middle East respiratory syndrome coronavirus (MERS-CoV) infections and 935 associated deaths, with a mortality rate of 36%, had been reported to the World Health Organization (WHO). However, there are still no vaccines for MERS-CoV, which makes the prevention and control of MERS-CoV difficult. In this study, we generated two DNA vaccine candidates by integrating MERS-CoV Spike (S) gene into a replicating Vaccinia Tian Tan (VTT) vector. Compared to homologous immunization with either vaccine, mice immunized with DNA vaccine prime and VTT vaccine boost exhibited much stronger and durable humoral and cellular immune responses. The immunized mice produced robust binding antibodies and broad neutralizing antibodies against the EMC2012, England1 and KNIH strains of MERS-CoV. Prime-Boost immunization also induced strong MERS-S specific T cells responses, with high memory and poly-functional (CD107a-IFN-γ-TNF-α) effector CD8+ T cells. In conclusion, the research demonstrated that DNA-Prime/VTT-Boost strategy could elicit robust and balanced humoral and cellular immune responses against MERS-CoV-S. This study not only provides a promising set of MERS-CoV vaccine candidates, but also proposes a heterologous sequential immunization strategy worthy of further development.

Amino acid substitution of the membrane-proximal external region alter neutralization sensitivity in a chronic HIV-1 clade B infected patient.

The membrane-proximal external region (MPER) represents a highly conserved region of the Human Immunodeficiency Virus (HIV) envelope glycoprotein (env) targeted by several broadly neutralizing antibodies (bnAbs). In this study, we employed single genome amplification to amplify 34 full-length env sequences from the 2005 plasma sample of CBJC504, a chronic HIV-1 clade B infected individual. We identified three amino acid changes (N671S, D674N, and K677R) in the MPER. A longitudinal analysis revealed that the proportion of env sequences with MPER mutations increased from 26.5 % in 2005 to 56.0 % in 2009, and the sequences with the same mutation clustered together. Nine functional pseudoviruses were generated from the 34 env sequences to examine the effect of these mutations on neutralizing activity. Pseudoviruses carrying N674 or R677 mutations demonstrate increased sensitivity to autologous plasma and monoclonal antibodies 2F5, 4E10, and 10E8. Reverse mutations were performed in env including N674, R677, D659, and S671/N677 mutations, to validate the impact of the mutations on neutralizing sensitivity. Neutralization assays indicated that the N671S mutation increased neutralization sensitivity to 2F5 and 10E8. The amino acid R at position 677 increased viral resistance to 10E8, whereas N enhanced viral resistance to 4E10 and 10E8. It has been proposed that critical amino acids in the extra-MPER and the number of potential N-like glycosylation sites (PNGSs) in the V1 loop may have an impact on neutralizing activity. Understanding the mutations and evolution of MPER in chronically infected patients with HIV-1 is crucial for the design and development of vaccines that trigger bnAbs against MPER.

Sequential heterologous immunization with COVID-19 vaccines induces broader neutralizing responses against SARS-CoV-2 variants in comparison with homologous boosters.

The recently prevalent variants of concerns (VOCs) of SARS-CoV-2 belong to Omicron variants which display increased transmissibility and evade from immune protection generated by vaccines and/or natural infections. Better immunization strategies should be explored to induce broader immune responses against evolving SARS-CoV-2 variants. Here, we used inactivated vaccines derived from ancestral (Wu), Delta (Del) and Omicron (Omi) strains to immunize mice with homologous booster (3 × Wu, 3 × Del and 3 × Omi) or heterologous sequential booster (Wu/Del/Omi and Omi/Wu/Del) to evaluate their responses against two pre-Omicron (Wu and Del) and four Omicron variants. Even though neutralization responses against Wu and Del variants were similar in heterologous and homologous immunization groups, heterologous immunization groups induced significantly stronger neutralizing antibody against BA.1 (4.1-11 folds higher) and BA.2 (4.7-14.2 folds higher) than those of homologous immunization groups. While homologous immunization only induced strong neutralizing responses to either pre-Omicron variants (Wu and Del) in 3 × Wu and 3 × Del groups or to Omicron variants (BA.1 and BA.2) in 3 × Omi group, heterologous immunization groups induced strong and broader neutralizing responses to both pre-Omicron (Wu, Del) and Omicron variants (BA.1 and BA.2). Homologous and heterologous immunization groups elicited similar antigen-specific T cell (IFN-γ+) and B cell responses. Compared with homologous immunization, heterologous immunization could induce stronger plasma cell responses, which have the potential to generate broader and stronger neutralizing antibodies. However, neither heterologous nor homologous immunization groups induced strong neutralizing antibody against variants with bigger genetic deviation, such as BA.4/5 or BF.7, only weak neutralizing responses were induced. Surveillance on SARS-CoV2 variants evolution and immunization strategy are needed to explore better vaccines with broader and stronger neutralizing antibodies against post pandemic COVID-19.

Does the periportal end of a double-lumen endobronchial tube need to be fixed to prevent dislocation of the cuffed end caused by a change in position? A randomized controlled trial.

OBJECTIVE: This study aimed to evaluate the effects on the dislocation and misalignment of the cuffed end of a double-lumen endobronchial tube (DLT) when a patient moves from a horizontal to a lateral position without fixation. METHODS: A total of 148 patients who had undergone video-assisted thoracoscope surgery were enrolled and randomly divided into two groups: a group in which the periportal end of the DLT was fixed with tape (group I; n = 74) and a group in which the periportal end of the DLT remained unfixed (group II; n = 74). Both groups were given an intravenous induction for double-lumen endobronchial intubation and then moved from a horizontal position to a lateral position, after which the alignment of the bronchial cuffed end of the DLT was assessed using a fiberoptic bronchoscope. RESULTS: After lateral position, the dislocation rate of group I and group II was 44.6% and 20.2%, and the misalignment rate was 27.0% and 8.1%, respectively, the incidence of dislocation and misalignment was significantly lower in group II than in group I after the change to a lateral position (p < 0.05). After lateral position, the total rate of airway injury was 25.7% in group I and 5.4% in group II, the incidence of airway injury was significantly lower in group II than in group I (p < 0.05), as was the incidence of sore throat, hoarseness, and cough on postoperative day 1 (p < 0.05). The average outward dislocation of the periportal end of the DLT in group II was 1.5 cm. CONCLUSION: A DLT without periportal fixation is less likely to be displaced and poorly aligned when the patient moves from a horizontal to a lateral position, which could facilitate intra-operative management and reduce the incidence of postoperative complications.

Through a randomized controlled trial, this study innovatively found that no double-lumen endobronchial tube (DLT) peripheral tape binding can prevent the dislocation and misalignment of the DLT bronchial cuffed end in patients undergoing thoracic surgery from horizontal to lateral position.

Meta-analysis of the effects of CPAP therapy on estimated glomerular filtration rate in patients with obstructive sleep apnea.

PURPOSE: Obstructive sleep apnea (OSA) is highly prevalent in patients with chronic kidney disease and may lead to a loss of kidney function. However, it remains unclear whether or not continuous positive airway pressure (CPAP) treatment improves the estimated glomerular filtration rate (eGFR) in patients with OSA. This meta-analysis was designed to investigate the effect of CPAP therapy on eGFR in patients with OSA. METHODS: We searched the electronic databases Web of Science, Cochrane Library, PubMed, and Embase through June 1, 2022. Information about patients, CPAP duration, gender distribution, pre- and post-CPAP treatment eGFR, and age of patients were collected for further analysis. We applied the standardized mean difference (SMD) with a 95%confidence interval (CI) to analyze the pooled effects. Both Stata 12.0 software and Review Manager 5.2 software were employed for all statistical analyses. RESULTS: A sample of 13 studies with 519 patients was included in the meta-analysis. There was no significant change of eGFR levels before and after CPAP usage for patients with OSA (SMD = - 0.05, 95%CI: - 0.30 to 0.19, Z = 0.43, p = 0.67). However, subgroup analysis revealed that the level of eGFR was obviously decreased after CPAP therapy in patients with OSA and CPAP use duration > 6 months (SMD = - 0.30, 95% CI = - 0.49 to - 0.12, z = 3.20, p = 0.001), and elderly patients (> 60 years) (SMD = - 0.32, 95% CI = - 0.52 to - 0.11, z = 3.02, p = 0.002). CONCLUSIONS: Meta-analysis confirmed that OSA treatment with CPAP has no clinically significant effect on eGFR.