Delta variant of COVID-19: A simple explanation

Description of Post-discharge Outcomes of Patients with COVID-19 in a Tertiary Referral Center in the Philippines

Background and Objectives

The immediate post-discharge period of COVID-19 patients is a vulnerable state due to several complications that may arise during this time. Some patients get readmitted shortly after being discharged while others report persistence of symptoms, develop specialized needs, or observe a decline from their baseline functional capacity. Information on the outcomes of post-COVID discharge patients in our institution is currently lacking. This study described the outcomes of patients with COVID-19 after their discharge from the service areas of Philippine General Hospital.

Methods

This study is a retrospective chart review involving charts of all adult patients discharged from the PGH COVID service areas last August 2021 to October 2021. Data from their follow up consults at 1 week, 1 month, and 3 months post-discharge were reviewed. Baseline characteristics and post-discharge outcomes including post-COVID symptoms, special care needs, mortality, rehospitalization, emergency consult, level of dependence, and ability to return to work were assessed.

Results

A total of 171 patient charts were included. The mean age of patients was 53.7 years. Most were male (60.2%), unemployed (59.7%), non-smoker (55%), hypertensive (57.9%), diabetic (50.2%), and obese (50.2%). Most of them were oxygen requiring (80%) and with severe to critical COVID infection (72.5%) during admission. At 3 months post-discharge, 113 (66%) were stable and able to complete the follow up, 8 (4.6%) died, 9 (5.2%) got readmitted, and 41 (23.9%) were lost to follow up. Among those who were able to follow up after 3 months, 84 (74%) were asymptomatic. Among those who remained symptomatic, the most common symptoms were dyspnea, fatigue, and cough. After 3 months, 100 (88%) did not require special care needs, 100 (88%) were fully independent, and 45 (39.8%) were able to return to baseline work.

Conclusions

Despite the majority of patients having severe to critical COVID infection during admission, most were asymptomatic within 3 months post-discharge. In those who developed persistent symptoms, dyspnea, cough, and fatigue were the most common symptoms identified regardless of COVID severity. Majority did not require special care needs.

VEGFR and DPP-IV as Markers of Severe COVID-19 and Predictors of ICU Admission

The pathophysiology of the severe course of COVID-19 is multifactorial and not entirely elucidated. However, it is well known that the hyperinflammatory response and cytokine storm are paramount events leading to further complications. In this paper, we investigated the vascular response in the pathophysiology of severe COVID-19 and aimed to identify novel biomarkers predictive of ICU admission. The study group consisted of 210 patients diagnosed with COVID-19 (age range: 18-93; mean ± SD: 57.78 ± 14.16), while the control group consisted of 80 healthy individuals. We assessed the plasma concentrations of various vascular factors using the Luminex technique. Then, we isolated RNA from blood mononuclear cells and performed a bioinformatics analysis investigating various processes related to vascular response, inflammation and angiogenesis. Our results confirmed that severe COVID-19 is associated with vWF/ADAMTS 13 imbalance. High plasma concentrations of VEGFR and low DPP-IV may be potential predictors of ICU admission. SARS-CoV-2 infection impairs angiogenesis, hinders the generation of nitric oxide, and thus impedes vasodilation. The hypercoagulable state develops mainly in the early stages of the disease, which may contribute to the well-established complications of COVID-19.

It is time to improve the acceptance of COVID-19 vaccines among people with chronic diseases: A systematic review and meta-analysis

This study aims to investigated COVID-19 vaccine acceptance among people with chronic diseases and the factors correlating with their vaccination hesitancy. The articles were searched in PubMed, Ovid, EMBASE, and web of science databases between December 2019 and October 2022. Cross-sectional studies, including the acceptance of the COVID-19 vaccine by patients with chronic diseases (≥18 years old), were included in this study. The outcomes included the proportion and 95% confidence interval (95% CI) of chronic disease patients willing to be vaccinated and the odds ratio (OR) and 95% CI of correlating factors. The source of heterogeneity was analyzed through meta-regression and subgroup analysis. We included 31 studies involving 57 875 patients with chronic disease. The overall COVID-19 vaccine acceptance among patients with chronic disease was 0.65 (95% CI, 0.59-0.72). The acceptance among the elderly patients was 0.53 (95% CI, 0.26-0.80). South America had the highest COVID-19 vaccine acceptance rate and Asia the lowest, while on a country level, the United Kingdom had the highest acceptance rate among patients with chronic diseases. People with rheumatic immune diseases had the lowest rate of COVID-19 vaccine acceptance. Concerns about vaccine safety had a statistically different effect on acceptance. Overall, the health systems ought to focus on educating specific groups of individuals on the benefits of COVID-19 vaccination and addressing safety concerns.

Delta variant (B.1.617.2) of SARS-CoV-2: Mutations, impact, challenges and possible solutions

Since commencement of COVID-19 pandemic, several SARS-CoV-2 variants have emerged amid containment efforts via vaccination. The Delta variant (B.1.617.2), discovered in October 2020, was designated as a VOC by the WHO on May 11, 2021. The enhanced transmissibility of Delta variant has been associated with critical mutations such as D614G, L452R, P681R, and T478K in the S-protein. The increased affinity of the S-protein and ACE2 has been postulated as a key reason for decreased vaccine efficacy. As per evidence, the Delta variant possesses increased transmissibility and decreased vaccine efficacy compared to other VOCs like Alpha and Beta. This has led to concerns regarding the acquisition of novel mutations in the Delta variant and outbreaks in vulnerable communities, including vaccinated people. In this mini-review of Delta variant, we have explained its evolution and characteristics, the impact of spike mutations on infectivity and immune evasion, and measures to combat future outbreaks.

SARS-CoV-2: phenotype, genotype, and characterization of different variants

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19), a major international public health concern. Because of very similar amino acid sequences of the seven domain names, SARS-CoV-2 belongs to the Coronavirinae subfamily of the family Coronaviridae, order Nidovirales, and realm Riboviria, placed in exceptional clusters, but categorized as a SARS-like species. As the RNA virus family with the longest genome, the Coronaviridae genome consists of a single strand of positive RNA (25–32 kb in length). Four major structural proteins of this genome include the spike (S), membrane (M), envelope (E), and the nucleocapsid (N) protein, all of which are encoded within the 3′ end of the genome. By engaging with its receptor, angiotensin-converting enzyme 2 (ACE2), SARS-CoV-2 infects host cells. According to the most recent epidemiological data, as the illness spread globally, several genetic variations of SARS-CoV-2 appeared quickly, with the World Health Organization (WHO) naming 11 of them. Among these, seven SARS-CoV-2 subtypes have received the most attention. Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.617.2) are now designated as variations of concern (VOC) (B.1.1.529). Lambda (C.37) and Mu are variations of interest (VOI) (B.1.621). The remaining six are either being monitored or are no longer considered a threat. On the basis of studies done so far, antiviral drugs, antibiotics, glucocorticoids, recombinant intravenous immunoglobulin, plasma therapy, and IFN-α2b have been used to treat patients. Moreover, full vaccination is associated with lower infection and helps prevent transmission, but the risk of infection cannot be eliminated completely in vaccinated people.

Omicron variant and change of electrostatic interactions between receptor binding domain of severe acute respiratory syndrome coronavirus 2 with the angiotensin-converting enzyme 2 receptor

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are currently a new hazard. Since the first appearance of classical SARS-CoV-2 in late 2019, pathogen genetic alterations have continued to occur, and some new hazardous forms have already emerged. The underlying pathophysiological process leading to clinical issue is molecular change caused by genetic mutation.

AIM

To determine the change in the interaction between receptor binding domain of omicron variant SARS-CoV-2 and the angiotensin-converting enzyme 2 (ACE2).

METHODS

The researchers investigated how alterations in the binding area of the SARS receptor CoV2 interacted electrostatically with the ACE2 receptor. In this report, three important coronavirus disease 2019 variants, beta, delta, and omicron, were investigated.

RESULTS

According to this study, there was a change of electrostatic interactions between the receptor binding domain of SARS-CoV-2 with the ACE2 receptor due to each studied variant. The most change was detected in omicron variant followed by delta variant and beta variant.

CONCLUSION

Our results may support the clinical finding that the omicron variant is more transmissible than the wild type and other variants.

Cancer vaccines: past, present and future; a review article

Immunotherapy and vaccines have revolutionized disease treatment and prevention. Vaccines against infectious diseases have been in use for several decades. In contrast, only few cancer vaccines have been approved for human use. These include preventative vaccines against infectious agents associated with cancers, and therapeutic vaccines used as immunotherapy agents to treat cancers. Challenges in developing cancer vaccines include heterogeneity within and between cancer types, screening and identification of appropriate tumour-specific antigens, and the choice of vaccine delivery platforms. Recent advances in all of these areas and the lessons learnt from COVID-19 vaccines have significantly boosted interest in cancer vaccines. Further advances in these areas are expected to facilitate development of effective novel cancer vaccines. In this review, we aim to discuss the past, the present, and the future of cancer vaccines.

COVID-19 Genetic Variants and Their Potential Impact in Vaccine Development

In the two years since the SARS-CoV-2 pandemic started, it has caused over 5 million deaths and 400 million infected cases, and the world continues to be on high alert for COVID-19. Among the variants of interest and concern of SARS-CoV-2, the current Omicron (B.1.1.529) and stealth Omicron (BA.2) raised serious concerns due to rapid rates of infection caused by numerous mutations in the spike protein, which could escape from the antibody-mediated neutralization and increase the risk of reinfections. Hence, this work aims to describe the most relevant mutations in the SARS-CoV-2 spike protein, discuss vaccine against variant of concerns, describe rare adverse events after COVID-19 vaccination, introduce the most available promising COVID-19 vaccine candidates, and provide few perspectives of the future variants.

Breakthrough infections with the SARS-CoV-2 Delta variant: Vaccinations halved transmission risk

Objectives

The SARS-CoV-2 Delta variant (B.1.617.2) is associated with increased infectivity. Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated individuals and transmission risk are limited. The aim of this study was to provide estimates of transmission risk in Delta variant breakthrough infections.

Study design

A matched case-control study was performed..

Methods

To analyse onward transmission of fully vaccinated individuals infected with B.1.617.2, we compared 85 patients (vaccination group [VG]) with an age- and sex-matched unvaccinated control group (CG; n = 85).

Results

Transmission of B.1.617.2 was significantly reduced (halved) in the VG. The number of infected contacts to total number of contacts per infected person was 0.26 ± 0.40 in the VG vs 0.56 ± 0.45 in the CG (P = .001). Similarly, fully vaccinated contacts were less likely to be infected by fully vaccinated infected persons (IPs) than by unvaccinated IPs (20.0% vs 37.5%), although this association was not significant.

Conclusions

Fully vaccinated contacts had 50% less transmissions than unvaccinated individuals. These findings must be verified in larger sample populations, and it is especially important to investigate the role of vaccination status of close contacts.

How optimal allocation of limited testing capacity changes epidemic dynamics

Insufficient testing capacity has been a critical bottleneck in the worldwide fight against COVID-19. Optimizing the deployment of limited testing resources has therefore emerged as a keystone problem in pandemic response planning. Here, we use a modified SEIR model to optimize testing strategies under a constraint of limited testing capacity. We define pre-symptomatic, asymptomatic, and symptomatic infected classes, and assume that positively tested individuals are immediately moved into quarantine. We further define two types of testing. Clinical testing focuses only on the symptomatic class. Non-clinical testing detects pre- and asymptomatic individuals from the general population, and a concentration parameter governs the degree to which such testing can be focused on high infection risk individuals. We then solve for the optimal mix of clinical and non-clinical testing as a function of both testing capacity and the concentration parameter. We find that purely clinical testing is optimal at very low testing capacities, supporting early guidance to ration tests for the sickest patients. Additionally, we find that a mix of clinical and non-clinical testing becomes optimal as testing capacity increases. At high but empirically observed testing capacities, a mix of clinical testing and non-clinical testing, even if extremely unfocused, becomes optimal. We further highlight the advantages of early implementation of testing programs, and of combining optimized testing with contact reduction interventions such as lockdowns, social distancing, and masking.

Preparation of highly specific monoclonal antibodies against SARS-CoV-2 nucleocapsid protein and the preliminary development of antigen detection test strips

The coronavirus disease 2019 (COVID‐19) is outbreaking all over the world. To help fight this disease, it is necessary to establish an effective and rapid detection method. The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is involved in viral replication, assembly, and immune regulation and plays an important role in the viral life cycle. Moreover, the N protein also could be a diagnostic factor and potential drug target. Therefore, by synthesizing the N gene sequence of SARS‐CoV‐2, constructing the pET‐28a (+)‐N recombinant plasmid, we expressed the N protein in Escherichia coli and obtained 15 monoclonal antibody (mAbs) against SARS‐CoV‐2‐N protein by the hybridomas and ascites, then an immunochromatographic test strip method detecting N antigen was established. In this study, we obtained 14 high‐titer and high‐specificity monoclonal antibodies, and the test strips exclusively react with the SARS‐CoV‐2‐N protein and no cross‐reactivity with other coronavirus and also recognize the recombinant N protein of Delta (B.1.617.2) variant. These mAbs can be used for the early and rapid diagnosis of SARS‐CoV‐2 infection through serological antigen.