SARS-CoV-2 and COVID-19: A Narrative Review

The Effect of Coronavirus Disease 2019 and Other Emerging Infections on Dentistry

The appearance of coronavirus disease 2019 (COVID-19) and other emerging infections has significantly impacted the field of dentistry, leading to widespread changes in practices and protocols. This has included the implementation of strict infection control measures, such as meticulous use of personal protective equipment, minimizing aerosol-generating procedures, and the adoption of teledentistry to reduce in-person contact. To date, the complete impact of delays in dental care caused by lockdowns has yet to be determined. The challenges faced during the COVID-19 pandemic have propelled innovation, shaping a new era of dentistry focused on safety against novel and re-emerging infections.

Remdesivir: treatment of COVID-19 in special populations

Remdesivir (RDV) is the mainstay antiviral therapy for moderate to severe COVID-19. Although remdesivir was the first drug approved for COVID-19, information about its efficacy and safety profile is limited in a significant segment of the population, such as people with underlying diseases, the elderly, children, and pregnant and lactating women. The efficacy and safety profile of RDV in disease progression, renal impairment, liver impairment, immunosuppression, geriatrics, pediatrics, pregnancy, and breastfeeding in COVID-19 patients was evaluated. The databases searched included Embase, Scopus, and PubMed. Only English language studies enrolling specific subpopulations with COVID-19 and treated with RDV were included. Thirty-nine clinical trials, cohorts, cross-sectional studies, and case series/reports were included. Most supported the benefits of RDV therapy for COVID-19 patients, such as lessening the duration of hospitalization, alleviating respiratory complications, and reducing mortality. Adverse effects of RDV, including liver and kidney impairment, were, for the most part, moderate to mild, supporting the safety profile of RDV therapy. RDV therapy was well tolerated, no new safety signals were detected, and liver function test abnormalities were the most common adverse events. Moreover, RDV, for the most part, was effective in managing the complications of COVID-19 and reducing mortality in these patients, except for patients with kidney impairment. Future studies, including RCTs, should include these subpopulations of patients to avoid delays associated with receiving proper medication through compassionate use programs.

A Low Number of Baselines γδ T Cells Increases the Risk of SARS-CoV-2 Post-Vaccination Infection

Background: The COVID-19 pandemic is the biggest global health problem in the last hundred years. The efficacy of the vaccine to protect against severe disease is estimated to be 70-95% according to the studies carried out, although there are aspects of the immune response to the vaccine that remain unclear. Methods: Humoral and cellular immunity after the administration of three doses of the Pfizer-BioNTech and Oxford AstraZeneca vaccines against SARS-CoV-2 over one year and the appearance of post-vaccination COVID-19 were studied. SARS-CoV-2 IgG and IgA antibodies, αβ and γδ T-cell subsets, and their differentiation stages and apoptosis were analyzed. Results: Anti-SARS-CoV-2 IgG and IgA antibodies showed a progressive increase throughout the duration of the study. This increase was the greatest after the third dose. The highest levels were observed in subjects who had anti-SARS-CoV-2 antibodies prior to vaccination. There was an increase in CD4+ αβ, CD8+ γδ and TEM CD8+ γδ T cells, and a decrease in apoptosis in CD4+ CD8+ and CD56+ αβ and γδ T cells. Post-vaccination SARS-CoV-2 infection was greater than 60%. The symptoms of COVID-19 were very mild and were related to a γδ T cell deficit, specifically CD8+ TEMRA and CD56+ γδ TEM, as well as lower pre-vaccine apoptosis levels. Conclusions: The results unveil the important role of γδ T cells in SARS-CoV-2-vaccine-mediated protection from the disease.

Crystal Structures of Fusion Cores from CCoV-HuPn-2018 and SADS-CoV

Cross-species spillover to humans of coronaviruses (CoVs) from wildlife animal reservoirs poses marked and global threats to human and animal health. Recently, sporadic infection of canine coronavirus-human pneumonia-2018 (CCoV-HuPn-2018) in hospitalized patients with pneumonia genetically related to canine and feline coronavirus were identified. In addition, swine acute diarrhea syndrome coronavirus (SADS-CoV) had the capability of broad tropism to cultured cells including from humans. Together, the transmission of Alphacoronaviruses that originated in wildlife to humans via intermediate hosts was responsible for the high-impact emerging zoonosis. Entry of CoV is mainly mediated by Spike and formation of a typical six helix bundle (6-HB) structure in the postfusion state of Spike is pivotal. Here, we present the complete fusion core structures of CCoV-HuPn-2018 and SADS-CoV from Alphacoronavirus at 2.10 and 2.59 Å, respectively. The overall structure of the CCoV-HuPn-2018 fusion core is similar to Alphacoronavirus like HCoV-229E, while SADS-CoV is analogous to Betacoronavirus like SARS-CoV-2. Collectively, we provide a structural basis for the development of pan-CoV small molecules and polypeptides based on the HR1-HR2 complex, concerning CCoV-HuPn-2018 and SADS-CoV.

Single-cell transcriptomic atlas of distinct early immune responses induced by SARS-CoV-2 Proto or its variants in rhesus monkey

Immune responses induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection play a critical role in the pathogenesis and outcome of coronavirus disease 2019 (COVID-19). However, the dynamic profile of immune responses postinfection by SARS-CoV-2 variants of concern (VOC) is not fully understood. In this study, peripheral blood mononuclear cells single-cell sequencing was performed to determine dynamic profiles of immune response to Prototype, Alpha, Beta, and Delta in a rhesus monkey model. Overall, all strains induced dramatic changes in both cellular subpopulations and gene expression levels at 1 day postinfection (dpi), which associated function including adaptive immune response, innate immunity, and IFN response. COVID-19-related genes revealed different gene profiles at 1 dpi among the four SARS-CoV-2 strains, including genes reported in COVID-19 patients with increased risk of autoimmune disease and rheumatic diseases. Delta-infected animal showed inhibition of translation pathway. B cells, T cells, and monocytes showed much commonality rather than specificity among the four strains. Monocytes were the major responders to SARS-CoV-2 infection, and the response lasted longer in Alpha than the other strains. Thus, this study reveals the early immune responses induced by SARS-CoV-2 Proto or its variants in nonhuman primates, which is important information for controlling rapidly evolving viruses.

Modeling the XBB strain of SARS-CoV-2: Competition between variants and impact of reinfection

XBB, an Omicron subvariant of SARS-CoV-2 that began to circulate in late 2022, has been dominant in the US since early 2023. To quantify the impact of XBB on the progression of COVID-19, we propose a new mathematical model which describes the interplay between XBB and other SARS-CoV-2 variants at the population level and which incorporates the effects of reinfection. We apply the model to COVID-19 data in the US that include surveillance data on the cases and variant proportions from the New York City, the State of New York, and the State of Washington. Our fitting and simulation results show that the transmission rate of XBB is significantly higher than that of other variants and the reinfection from XBB may play an important role in shaping the pandemic/epidemic pattern in the US.

Remdesivir: A Review in COVID-19

Remdesivir (Veklury®), a nucleotide analogue prodrug with broad-spectrum antiviral activity, is approved for the treatment of coronavirus disease 2019 (COVID-19), the illness caused by severe acute respiratory syndrome coronavirus 2 infection. Unlike some antivirals, remdesivir has a low potential for drug-drug interactions. In the pivotal ACTT-1 trial in hospitalized patients with COVID-19, daily intravenous infusions of remdesivir significantly reduced time to recovery relative to placebo. Subsequent trials provided additional support for the efficacy of remdesivir in hospitalized patients with moderate or severe COVID-19, with a greater benefit seen in patients with minimal oxygen requirements at baseline. Clinical trials also demonstrated the efficacy of remdesivir in other patient populations, including outpatients at high risk for progression to severe COVID-19, as well as hospitalized paediatric patients. In terms of mortality, results were equivocal. However, remdesivir appeared to have a small mortality benefit in hospitalized patients who were not already being ventilated at baseline. Remdesivir was generally well tolerated in clinical trials, but pharmacovigilance data found an increased risk of hepatic, renal and cardiovascular adverse drug reactions in the real-world setting. In conclusion, remdesivir represents a useful treatment option for patients with COVID-19, particularly those who require supplemental oxygen.

Medical outcomes of children with neurodevelopmental disorders after SARS-CoV-2 vaccination: A six-month follow-up study

INTRODUCTION

The BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines have been approved for children and adolescents for protecting against SARS-CoV-2 infection. This longitudinal study aimed to compare adverse outcomes after SARS-CoV-2 vaccination in children with neurodevelopmental disorders (ND) (e.g., attention-deficit/hyperactivity disorder [ADHD], autism spectrum disorder [ASD], communication disorders, intellectual disability, and tic disorders) and healthy control children.

METHODS

A total of 1335 children who received the SARS-CoV-2 vaccination (762 children with ND and 573 healthy controls) were recruited. All subjects were followed-up for 180 days, and outcome events were defined as outpatient department (OPD) or emergency department (ER) visits during follow-up. Multivariate Cox proportional hazards regression models were used to identify the potential differences in outcomes between the propensity score-matched ND group (n = 311) and the control group (n = 311), and to explore the factors associated with outcomes among all children with ND (n = 762).

RESULTS

Compared with the control group, children with ND exhibited a higher likelihood of subsequent OPD or ER visits and paediatric neurology OPD visits after the first dose of vaccination. However, we found that only a small proportion of the children visited the OPD or ER because of adverse vaccination-related effects. Among all children with ND, those with communication disorders showed a higher likelihood of any OPD or ER visit. Paediatric neurology OPD visits were associated with communication disorders, intellectual disability, and methylphenidate and aripiprazole prescriptions. ADHD and ASD were not associated with adverse outcomes.

CONCLUSIONS

No specific ND diagnosis or medication use clearly increased the risk of adverse effects of SARS-CoV-2 vaccination. Children with ND can be reassured that the SARS-CoV-2 vaccination is a safe regimen to protect themselves.

Monoclonal Antibodies and Antivirals against SARS-CoV-2 Reduce the Risk of Long COVID: A Retrospective Propensity Score-Matched Case-Control Study

Long COVID is a complex condition affecting quality of life, with limited therapeutic options. We investigated the occurrence of long COVID in subjects receiving early therapy with monoclonal antibodies (mAbs) or antivirals to reduce the risk of COVID-19 progression. In this retrospective study we enrolled 737 adult patients (aged 65.16 ± 13.46; 361F), who experienced COVID-19 between January 2021 and March 2022. Antiviral or mAbs were administered to symptomatic patients who did not require oxygen therapy or hospital admission for SARS-CoV-2 infection, and who were at high risk of progression to severe disease, as identified by age > 65 years or the presence of comorbidities. Long COVID, defined as newly or persistent long-term symptoms 4 weeks after the onset of the acute illness, was reported in 204 cases (28%). Age (OR 1.03; p < 0.001), gender (OR 1.88; p < 0.001) and at least three comorbidities (OR 3.49; p = 0.049) were directly associated with long COVID; conversely, vaccination (OR 0.59; p = 0.005) and mAbs/antivirals (OR 0.44; p = 0.002) were independently associated with a reduced risk of long COVID. At a propensity-score-matched analysis, the mAbs/antivirals group had a significantly lower occurrence of long COVID in comparison with untreated controls (11% vs. 34%; p = 0.001). In conclusion, mAbs and antivirals administered against the progression of COVID-19 were associated with a reduced risk of long COVID.