Public Health Emergency: COVID-19 Variants

C annabis  is the most widely used psychotropic substance worldwide and is the second most commonly smoked substance after tobacco. Tobacco use is associated with reduced air flow rate and lung volume; however, this association is not observed with cannabis use. In fact, one 2012 study found no association to exist between occasional and minimal cumulative cannabis usage and poor  pulmonary function . To determine the different effects of cannabis and/or tobacco, it is crucial to know the quantity of how much was smoked. Those who frequently use  tobacco  will typically smoke between ten and twenty cigarettes each day, whereas the average cannabis user will smoke two to three times per month. Many people first try cannabis in their late teens or early twenties, with some continuing to use cannabis for several years at modest doses. Since heavy cannabis users were comparatively uncommon in the study population, accurate estimates of the consequences of excessive usage...

C anadian researchers investigated how  severe acute respiratory syndrome coronavirus 2  (SARS-CoV-2) infection altered the microbiota composition of the host’s nasopharyngeal region. The risk and clinical outcomes of SARS-CoV-2 infection vary widely among individuals. However, the mechanisms underlying these differences in  coronavirus disease 2019  (COVID-19) progression and pathogenesis remain unclear. Studies have shown that the mucosal microbiome influences host toll-like receptor (TLR) expression, which is involved in virus detection. Studies have also shown the prevalence of bacterial co-infections in COVID-19 patients at 6.9%. Likewise, elevated nasal cytokines have been implicated in adverse clinical outcomes in influenza patients. Therefore, exploring upper respiratory tract microbiota compositional changes following SARS-CoV-2 infection could help evaluate its impact on  infection  severity. Overall, the study results presented a granular picture...

C hildren are at an increased risk of  COVID 2019  (COVID-19) and post-COVID-19 (long COVID) syndrome due to the lack of authorized vaccines for children, scare recommendations for pediatric vaccinations, low vaccine uptake, and social distancing difficulties among children. Knowledge of long COVID among children is vital to guide the identification and management of COVID-19 and long COVID by setting up multi-disciplinary long COVID clinics. In the present cross-sectional and nationwide Long COVID Kids DK study, researchers investigated the long COVID symptomatology and its impact on quality of life and absence from schools and daycare facilities among  SARS-CoV-2-infected  children aged <14 years in Denmark. The study comprised a 1:4 ratio of SARS-CoV-2 infected Danish children (cases) with diagnoses confirmed by  polymerase chain reaction  (PCR) between 1 January 2020 and 12 July 2021 (cases) and age- and sex-matched controls. The cases were identifie...

I n the current study, researchers investigated the degree to which infection with SARS-CoV-2 Omicron boosts cross-reactive B and T   cell immunity   against itself and other VOCs. The authors recruited a cohort of healthcare workers (HCWs) longitudinally followed from March 2020 to January 2022, who were individuals with different combinations of vaccination and infection histories. HCWs were identified from successive COVID-19 waves, viz., Alpha, Delta, and Omicron, and after partial (first dose), full (double dose), and booster (third dose) vaccination with the BNT162b2 vaccine. The nucleocapsid (N) and spike 1 (S1) receptor-binding domain (RBD) serology were longitudinally evaluated. The authors observed that the third exposure to the spike boosted S1 RBD titers in most HCW after two or three weeks of the most recent  vaccination . Moreover, antibody responses were plateaued by the third vaccination. Triple-vaccinated HCWs infected with SARS-CoV-2 Wuhan Hu-1 had signi...

In a recent Report published on the United States Center for Disease Control and Prevention (US-CDC) website, researchers described cases of  coronavirus disease 2019  (COVID-19)–related hospitalizations and emergency department (ED) visits in five to 15 days following Paxlovid (Nirmatrelvir/ritonavir) treatment. Nirmatrelvir/ritonavir, a  severe acute respiratory syndrome coronavirus 2  (SARS-CoV-2) main protease (Mpro) inhibitor, is marketed under the brand name Paxlovid. It received emergency use authorization (EUA) from the Food and Drug Administration (FDA) in December 2021 for mild to moderate COVID-19 cases likely at risk for developing severe disease. There are some published reports of recurrence of SARS-CoV-2 infections after completion of the Paxlovid treatment. However, there is a lack of real-world evidence to show that early intervention with Paxlovid prevents the progression of mild and moderate COVID-19 cases to severity. The study findings showed tha...

R esearchers assessed the   severe acute respiratory syndrome coronavirus 2   (SARS-CoV-2) variant-specific coronavirus disease 2019 (COVID-19) symptoms among residents of England. SARS-CoV-2-positive patients exhibit a wide range of symptoms, that differ among patients based on the causative  SARS-CoV-2 variant . The identification of high-risk individuals to acquire SARS-CoV-2 infections or transmit SARS-CoV-2 by their symptom profiles would benefit the population as healthcare authorities and governments have started to lift COVID-19 restrictions. The REaltime Assessment of Community Transmission-1 (REACT-1) study has tracked the prevalence and transmission of SARS-CoV-2  infections  and their clinical manifestations among the general population of England between May 1, 2020, and March 31, 2022. Study In the present study, researchers assessed the SARS-CoV-2 variant-specific  COVID-19  symptoms among the English population. COVID-19 symptomatology ...

  Scientists and policymakers have devised many strategies to reduce the emergence and spread of the   severe acute respiratory syndrome coronavirus-2   (SARS-CoV-2), the causal agent of the ongoing coronavirus disease 2019 pandemic (COVID-19). For example, people have been urged to practice physical distance, wear face masks, wash their hands frequently, and dine close to each other indoors. Introduction The implementation of various measures formulated to prevent the spread of the  SARS-CoV-2 virus  has also contributed significantly to the reduction in influenza cases. According to the Centers for Disease Control and Prevention (CDC), only 0.2% of specimens tested positive for influenza between September 28, 2020, and May 22, 2021. However, this was not the case in the previous three influenza seasons, where the number of positive cases ranged between 26.2 and 30.3%. Reduced influenza cases indicate the effectiveness of mitigation measures taken to limit SARS...

Coronavirus disease 2019   (COVID-19) vaccines have played a critical role in reducing transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission. However, with emerging reports of waning vaccine efficacy, there remains an urgent need to develop prophylactic measures against COVID-19. In a recent study, researchers screened ribonucleic acid interference (RNAi) against  SARS-CoV-2 . Study In the present study, researchers screened RNA interference (RNAi) triggers that targeted the SARS-CoV-2 genome and identified  hyper-potent  candidates. The team parsed the viral genome into a series of potential targets for short hairpin RNA (shRNA) by tilting the  SARS-CoV-2 genome  to shift each sequence away from each other by a single nucleotide (nt). Subsequently, several in silico filters were used to exclude target regions that had low synthesis fidelity, did not cross the minimal threshold of viral conservation, had sequential ch...

Several SARS-CoV-2 variants with altered infectivity and immune-evasive traits have emerged throughout the   coronavirus disease 2019   (COVID-19) pandemic. So far, five SARS-CoV-2 variants have been designated as VOCs. VOCs have been characterized based on the modifications within the spike (S) protein’s receptor-binding domain (RBD), which often render the mutant S protein with enhanced binding affinity or the potential to evade neutralizing antibodies (nAbs). A variant with higher infectivity and immune evasion would be extremely challenging to contain. Hence, it is essential to have a broadly protective vaccine against emergent variants. As such, researchers have been exploring novel approaches beyond conventional  antibody-centric technologies . Now, research is focused on characterizing the T cell responses, which correlate well with robust and durable immunity against  SARS-CoV-2 . While vaccine- or infection- elicited nAbs were considered the gold standard pr...

In a recent study, researchers generated an artificial intelligence (AI) resource to characterize the T cell epitope landscape for   severe acute respiratory syndrome coronavirus-2  (SARS-CoV-2) variants of concern (VOCs). Introduction Several SARS-CoV-2 variants with altered infectivity and immune-evasive traits have emerged throughout the  coronavirus disease 2019  (COVID-19) pandemic. So far, five SARS-CoV-2 variants have been designated as VOCs. VOCs have been characterized based on the modifications within the spike (S) protein’s receptor-binding domain (RBD), which often render the mutant S protein with enhanced binding affinity or the potential to evade neutralizing antibodies (nAbs). A variant with higher infectivity and immune evasion would be extremely challenging to contain. Hence, it is essential to have a broadly protective vaccine against emergent variants. As such, researchers have been exploring novel approaches beyond conventional  antibody-cent...

I n a recent study, researchers assessed   severe acute respiratory syndrome coronavirus 2   (SARS-CoV-2) Alpha, Delta, and Omicron variants’ resistance to nirmatrelvir (NIR), a protease inhibitor of SARS-CoV-2. Introduction In recent times, NIR has received authorization for first-line therapy for SARS-CoV-2-positive individuals with high risks of severe  coronavirus disease 2019  (COVID-19) and is also under consideration for long-COVID treatment. However, the clinical efficacy of NIR may reduce by the development of SARS-CoV-2 resistance, as observed previously for small-molecule inhibitor drugs against hepatitis B, C virus, human immunodeficiency virus (HIV), and influenza virus. The authors of the present study previously determined the efficacy of another protease inhibitor boceprevir (BOC), which is structurally similar to NIR, against  SARS-CoV-2  in cell culture experiments. Study In the present study, researchers extended their previous analysis b...