Effects of Smoking on COVID-19 Management and Mortality: An Umbrella Review.

Introduction: Smoking status appears to lead to a poor prognosis in COVID-19 patients. However, findings from the studies conducted on this topic have not been consistent, and further exploration is required. Methods: The objective of this umbrella review was to examine the effects of smoking on COVID-19 management and mortality. Online databases that included PubMed, Embase, Scopus, and Web of Science were searched using relevant keywords up to July 27, 2022. Articles were restricted to the English language, and the PRISMA protocol was followed. Results: A total of 27 systematic reviews, published from 2020 to 2022, were included. Individual studies included in the systematic reviews ranged from 8 to 186, with various population sizes. The consensus from the majority of systematic reviews was that COVID-19 smoker patients experience greater disease severity, disease progression, hospitalization rate, hospital admission duration, mechanical ventilation, ICU admission, and mortality rate. Conclusions: COVID-19 patients with a history of smoking (current and former) are vulnerable to adverse hospital outcomes and worse COVID-19 progression. Effective preventive and supportive approaches are required to decrease the risk of COVID-19 morbidity and mortality in patients with a history of smoking.

Vaccines for COVID-19: A Systematic Review of Feasibility and Effectiveness.

INTRODUCTION: Many potential vaccines for COVID-19 are being studied and developed. Several studies have reported on the safety and efficacy of these vaccines. This systematic review aimed to report on the current evidence concerning the feasibility and effectiveness of vaccines for COVID-19. METHODS: A systematic search was carried out utilizing the keywords in the online databases, including Scopus, Web of Science, PubMed, Embase, and Cochrane. We included both human and non-human studies because of the vaccine novelty, limiting our ability to include sufficient human studies. RESULTS: This review showed several SARS-CoV-2 vaccines to be currently under development using different platforms, including eight vaccines that are adenovirus-based vectors, six vaccines that are RNA-based formulations, one vaccine being DNA-based formulation, and other vaccines using other platforms, including lipid nanoparticles. Although the safety and efficacy profiles of these vaccines are still under debate, some countries have allowed for emergency use of some vaccines in at-risk populations, such as healthcare workers and the elderly. CONCLUSION: It is crucial to gather as much clinically relevant evidence as possible regarding the immunogenicity, efficacy, and safety profiles of available vaccines and adhere wisely to CDC protocols and guidelines for vaccine production.

Reinfection risk of novel coronavirus (COVID-19): A systematic review of current evidence.

BACKGROUND: There is recently a concern regarding the reinfection and reactivation of previously reCoVered coronavirus disease 2019 (CoVID-19) patients. AIM: To summarize the recent findings and reports of CoVID-19 reinfection in patients previously reCoVered from the disease. METHODS: This study was a systematic review of current evidence conducted in August 2020. The authors studied the probable reinfection risk of novel coronavirus (CoVID-19). We performed a systematic search using the keywords in online databases. The investigation adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist to ensure the reliability and validity of this study and results. RESULTS: We reviewed 31 studies. Eight studies described reCoVered patients with reinfection. Only one study reported reinfected patients who died. In 26 studies, there was no information about the status of the patients. Several studies indicated that reinfection is not probable and that post-infection immunity is at least temporary and short. CONCLUSION: Based on our review, we concluded that a positive polymerase chain reaction retest could be due to several reasons and should not always be considered as reinfection or reactivation of the disease. Most relevant studies in positive retest patients have shown relative and probably temporary immunity after the reCoVery of the disease.