Risk of SARS-CoV-2 reinfection: a systematic review and meta-analysis.

This meta-analysis aims to synthesize global evidence on the risk of reinfection among people previously infected with SARS-CoV-2. We systematically searched PubMed, Scopus, Embase and Web of Science as of April 5, 2021. We conducted: (1) meta-analysis of cohort studies containing data sufficient for calculating the incidence rate of SARS-CoV-2 reinfection; (2) systematic review of case reports with confirmed SARS-CoV-2 reinfection cases. The reinfection incidence was pooled by zero-inflated beta distribution. The hazard ratio (HR) between reinfection incidence among previously infected individuals and new infection incidence among infection-naïve individuals was calculated using random-effects models. Of 906 records retrieved and reviewed, 11 studies and 11 case reports were included in the meta-analysis and the systematic review, respectively. The pooled SARS-CoV-2 reinfection incidence rate was 0.70 (standard deviation [SD] 0.33) per 10,000 person-days. The incidence of reinfection was lower than the incidence of new infection (HR = 0.12, 95% confidence interval 0.09-0.17). Our meta-analysis of studies conducted prior to the emergency of the more transmissible Omicron variant showed that people with a prior SARS-CoV-2 infection could be re-infected, and they have a lower risk of infection than those without prior infection. Continuing reviews are needed as the reinfection risk may change due to the rapid evolution of SARS-CoV-2 variants.

Immunogenicity and protective efficacy of a DNA vaccine inducing optimal expression of the SARS-CoV-2 S gene in hACE2 mice.

The wide spread of coronavirus disease 2019 (COVID-19) has significantly threatened public health. Human herd immunity induced by vaccination is essential to fight the epidemic. Therefore, highly immunogenic and safe vaccines are necessary to control SARS-CoV-2, whose S protein is the antigenic determinant responsible for eliciting antibodies that prevent viral entry and fusion. In this study, we developed a SARS-CoV-2 DNA vaccine expressing the S protein, named pVAX-S-OP, which was optimized according to the human-origin codon preference and using polyinosinic-polycytidylic acid as an adjuvant. pVAX-S-OP induced specific antibodies and neutralizing antibodies in BALB/c and hACE2 transgenic mice. Furthermore, we observed 1.43-fold higher antibody titers in mice receiving pVAX-S-OP plus adjuvant than in those receiving pVAX-S-OP alone. Interferon gamma production in the pVAX-S-OP-immunized group was 1.58 times (CD3+CD4+IFN-gamma+) and 2.29 times (CD3+CD8+IFN-gamma+) lower than that in the pVAX-S-OP plus adjuvant group but higher than that in the control group. The pVAX-S-OP vaccine was also observed to stimulate a Th1-type immune response. When, hACE2 transgenic mice were challenged with SARS-CoV-2, qPCR detection of N and E genes showed that the viral RNA loads in pVAX-S-OP-immunized mice lung tissues were 104 times and 106 times lower than those of the PBS control group, which shows that the vaccine could reduce the amount of live virus in the lungs of hACE2 mice. In addition, pathological sections showed less lung damage in the pVAX-S-OP-immunized group. Taken together, our results demonstrated that pVAX-S-OP has significant immunogenicity, which provides support for developing SARS-CoV-2 DNA candidate vaccines.

Impact of proton pump inhibitors on the in-hospital outcome of COVID-19 patients: a retrospective study.

Background: Coronavirus disease 2019 (COVID-19) has triggered a global public health crisis. Proton pump inhibitors (PPIs) are one of the most commonly prescribed drugs. However, the effect of PPIs on the clinical outcomes of COVID-19 patients remains unclear. Methods: All COVID-19 patients admitted to the Wuhan Huoshenshan Hospital from February 2020 to April 2020 were retrospectively collected. Patients were divided into PPIs and non-PPIs groups. Logistic regression analyses were performed to explore the effects of PPIs on the outcomes of COVID-19 patients, including transfer to intensive care unit, mechanical ventilation, and death. Subgroup analyses were performed according to the presence of upper gastrointestinal symptoms potentially associated with acid and the routes, types, median total dosage, and duration of PPIs. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Results: Of the 3024 COVID-19 patients included, 694 and 2330 were in PPIs and non-PPIs groups, respectively. Univariate logistic regression analysis showed that PPIs significantly increased the risk of reaching the composite endpoint in COVID-19 patients (OR = 10.23, 95% CI = 6.90-15.16, p < 0.001). After adjusting for age, sex, comorbidities, other medications, and severe/critical COVID-19, PPIs were independently associated with an increased risk of reaching the composite endpoint (OR = 7.00, 95% CI = 4.57-10.71, p < 0.001). This association remained significant in patients with upper gastrointestinal symptoms and those who received an intravenous omeprazole alone, but not those who received oral lansoprazole or rabeprazole alone. It was not influenced by dosage or duration of PPIs. Conclusion: The use of intravenous PPIs alone during hospitalization may be associated with worse clinical outcome in COVID-19 patients.

Tracheotomy in COVID-19 Positive Patients - “New Normal” Workflow of Tracheotomy in the Era of SARS/COVID-19 Pandemic A Systematic Review (preprint)

Introduction: With the COVID-19 pandemic, a “new normal” on how surgeons and intensivists perform tracheotomy in COVID-19 patients is essential. We aim to summarize the recommendations and present the supporting evidence of these recommendations. Methods A search of published works on tracheotomy, tracheostomy, COVID-19, novel coronavirus, SARS-CoV-2 was performed on PubMed/MEDLINE/Cochrane Library. Articles relevant to the practice of tracheotomy on patients with COVID-19 were selected. The articles were then reviewed and divided into 4 key categories: 1) Personal protective equipment (PPE) in COVID-19 positive patients, 2) Adjunctive measures of airway management before definitive intervention in COVID-19 positive patients; 3) Timing of tracheotomy in COVID-19 positive patients; and 4) Perioperative considerations in performing tracheotomy in COVID-19 positive patients. Results and key points Firstly, enhanced PPE is recommended during tracheotomy of COVID-19 positive patients. Secondly, adjunctive airway management before definitive intervention includes the use of high flow nasal cannulas (HFNC). Thirdly, non-invasive ventilation via continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP) machines are not recommended. Fourth, the general consensus suggests that timing of tracheotomy should be at least 10 days after intubation. Finally, percutaneous dilatational tracheotomy (PDT) is likely to be associated with a lower risk of transmission of the virus to healthcare workers (HCW) than a surgical tracheotomy (ST). Other key precautions would include minimizing the use of diathermy. Conclusions The “new normal” workflow summarizes the ideal recommendations across published societal guidelines. Enhanced PPE should be recommended whenever possible. Adjunctive measures before definitive intervention of COVID-19 patients should be limited to the use of HFNC, and CPAP/BiPAP should be avoided. Tracheotomy should be performed after 10 days, although the long term sequelae of tracheal stenosis and pulmonary fibrosis should be ascertained with this approach.

Debate: Facing uncertainty with(out) a sense of control - cultural influence on adolescents' response to the COVID-19 pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has brought about healthcare, economic, and psychological crises around the world. The psychological impact on adolescents is likely going to be uneven across different societies, as cultures vary in terms of their dominant learning style that may influence how people cope with uncertainty and perceive their sense of control. We postulate that for adolescents in individualistic cultures where individual learning prevails, their sense of control might be undermined by societal disease-control regulations that restrict personal freedoms, while adolescents' sense of control might increase via participating in societal preventive efforts in collectivistic cultures where social learning is more prevalent. Individual differences regarding one's sense of control would, in turn, have implications for adolescents' short-term adjustments to COVID-19-related challenges and their future development.