COVID-19 mutations: An overview

Design, synthesis and in vitro validation of bivalent binders of SARS-CoV-2 spike protein: Obeticholic, betulinic and glycyrrhetinic acids as building blocks

SARS-CoV-2 is the virus responsible for the COVID-19 pandemic, which caused over 6.7 million deaths worldwide. The Spike protein plays a crucial role in the infection process, mediating the binding of the virus to its cellular receptor, angiotensin-converting enzyme 2 (ACE2), and its subsequent entry into target cells. Previous studies identified, through virtual screening, several natural products capable of binding to two distinct pockets of the Spike protein: triterpenoids binding to pocket 1 and bile acid derivatives binding to pocket 5. Building on these findings, our study advances the field by developing bivalent compounds 1-4 that through a spacer combine a triterpenoid (betulinic acid or glycyrrhetinic acid) with a semisynthetic bile acid derivative (obeticholic acid). These bivalent compounds are designed to simultaneously bind both pockets of the Spike protein, offering significant advantages over single molecules or the combination of the two natural products. In vitro cell assays using pseudotyped recombinant lentiviral particles with selected SARS-CoV-2 Spike proteins demonstrated that 1 and 2 exhibit enhanced activity in reducing viral entry into target cells compared to individual natural products, thus highlighting their potential as superior antiviral agents with reduced side effects.

Physical Activity and Mental Health After COVID-19 Recovery: Age and Sex Differences

(1) Background: The relationship between physical activity (PA) and mental health remains a topic of significant interest, particularly in populations recovering from COVID-19. This study aimed to examine the differences in PA levels and mental health parameters (anxiety, depression, and stress) across sex and age groups following COVID-19 recovery; (2) Methods: The sample of participants (n = 288) was selected using a random sampling method and consisted of participants of different ages and both sexes. Participants' self-reported PA was assessed using the International Physical Activity Questionnaire (IPAQ), while the Depression, Anxiety, and Stress Scale (DASS) was used to measure negative emotional states. The influence of COVID-19 recovery on PA and mental health (depression, anxiety, stress) was analyzed using MANOVA and follow-up univariate tests by age and sex. Statistical significance was set at p < 0.05, with SPSS (v23.0) used for data analysis; (3) Results: A statistically significant difference was observed between the initial and final measurements in PA levels (Wilk's Lambda = 0.95; p = 0.000) and mental health (Wilk's Lambda = 0.96; p = 0.000) with older individuals-particularly women-demonstrating improved PA levels and better mental health outcomes. In contrast, younger women exhibited a decline in both domains, with increased anxiety, depression, and stress symptoms. While younger men showed increased PA, their mental health parameters were slightly elevated, though still within normal ranges; (4) Conclusions: Our findings suggest that older individuals were better adapted to post-COVID challenges due to maturity and life experience, while younger populations may require additional support. The study underscored the complexity of the PA-mental health relationship and highlighted the need for further research, particularly among younger individuals recovering from COVID-19.

COVID-19 symptom severity and duration among outpatients, July 2021-May 2023: The PROTECT observational study

INTRODUCTION

With the emergence of new SARS-CoV-2 variants has come significant variations in disease manifestation, severity, and duration in non-hospitalized infected patients. To characterize symptom patterns and risk factors associated with symptom severity and duration, COVID-19 and influenza-like illness (ILI) outpatients and their contacts were enrolled at two sites in the United States of America and one site in Thailand.

METHODS

COVID-19 infection was confirmed at enrollment with a positive antigen or PCR test. Baseline demographics and medical histories were collected from participants at enrollment and daily self-reported symptom questionnaires were obtained to assess symptom severity and duration. Risk factors associated with symptom severity and duration were determined by multivariate logistic regression and Cox proportional hazards model.

RESULTS

Two hundred and forty one participants meeting the eligibility criteria were enrolled, including 174 confirmed COVID-19 cases (9% Delta and 90% Omicron), 33 ILI cases, and 34 healthy contacts. COVID-19 participants had a shorter median symptom duration of 9.0 (95% CI, 8.0-11.0) days than ILI participants. Infection with the Delta variant resulted in a longer symptom alleviation period compared to infection with the Omicron variant. The most commonly reported symptoms among COVID-19 participants were reported in the nasal and chest/respiratory domains of the FLU-PRO Plus. Participants infected with the Delta variant reported more symptoms overall, with significantly more symptoms affecting eyes and senses reported. 55% of SARS-CoV-2-positive participants reached a negative N1 Ct value by the day 14 study time point. No risk factors for moderate to severe symptoms were identified in this outpatient cohort. Male sex was associated with a shorter symptom duration.

CONCLUSION

Symptom manifestation varied among Delta and Omicron variants. Few risk factors were identified for increased symptom severity or duration.

Bioinformatic Tools for Studying the Cellular Immune Response to SARS-CoV-2, Vaccine Efficacy, and Future Pandemics at the Global Population Level

Antigen recognition by human leukocyte antigen (HLA) restriction is critical for an adequate antiviral response in both natural infection and vaccination. However, the overwhelming polymorphism of HLA, with nearly 40,000 alleles identified, is an important limitation for the global analysis of cellular immune responses and vaccine efficacy. In this narrative review, we included several immunoinformatics studies performed in our laboratory to circumvent this limitation. These analyses focused on studying the cellular immune responses restricted by the most common HLA alleles, and their role in vaccine efficacy. Computational studies validated experimentally, such as our laboratory has carried out, represent a useful, rapid, and cost-effective strategy to combat future pandemics.