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1.
Fractal and Fractional ; 6(5):232, 2022.
Article in English | ProQuest Central | ID: covidwho-1871288

ABSTRACT

With outbreaks of epidemics, an enormous loss of life and property has been caused. Based on the influence of disease transmission and information propagation on the transmission characteristics of infectious diseases, in this paper, a fractional-order SIR epidemic model is put forward on a two-layer weighted network. The local stability of the disease-free equilibrium is investigated. Moreover, a conclusion is obtained that there is no endemic equilibrium. Since the elderly and the children have fewer social tiers, a targeted immunity control that is based on age structure is proposed. Finally, an example is presented to demonstrate the effectiveness of the theoretical results. These studies contribute to a more comprehensive understanding of the epidemic transmission mechanism and play a positive guiding role in the prevention and control of some epidemics.

2.
EBioMedicine ; 77: 103904, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1867071

ABSTRACT

BACKGROUND: Nearly 4 billion doses of the BNT162b2-mRNA and CoronaVac-inactivated vaccines have been administrated globally, yet different vaccine-induced immunity against SARS-CoV-2 variants of concern (VOCs) remain incompletely investigated. METHODS: We compare the immunogenicity and durability of these two vaccines among fully vaccinated Hong Kong people. FINDINGS: Standard BNT162b2 and CoronaVac vaccinations were tolerated and induced neutralizing antibody (NAb) (100% and 85.7%) and spike-specific CD4 T cell responses (96.7% and 82.1%), respectively. The geometric mean NAb IC50 and median frequencies of reactive CD4 subsets were consistently lower among CoronaVac-vaccinees than BNT162b2-vaccinees. CoronaVac did not induce measurable levels of nucleocapsid protein-specific IFN-γ+ CD4+ T or IFN-γ+ CD8+ T cells compared with unvaccinated. Against VOCs, NAb response rates and geometric mean IC50 titers against B.1.617.2 (Delta) and B.1.1.529 (Omicron) were significantly lower for CoronaVac (50%, 23.2 and 7.1%, <20) than BNT162b2 (94.1%, 131 and 58.8%, 35.0), respectively. Three months after vaccinations, NAbs to VOCs dropped near to detection limit, along with waning memory T cell responses, mainly among CoronaVac-vaccinees. INTERPRETATION: Our results indicate that vaccinees especially CoronaVac-vaccinees with significantly reduced NAbs may probably face higher risk to pandemic VOCs breakthrough infection. FUNDING: This study was supported by the Hong Kong Research Grants Council Collaborative Research Fund (C7156-20GF and C1134-20GF); the Wellcome Trust (P86433); the National Program on Key Research Project of China (Grant 2020YFC0860600, 2020YFA0707500 and 2020YFA0707504); Shenzhen Science and Technology Program (JSGG20200225151410198 and JCYJ20210324131610027); HKU Development Fund and LKS Faculty of Medicine Matching Fund to AIDS Institute; Hong Kong Innovation and Technology Fund, Innovation and Technology Commission and generous donation from the Friends of Hope Education Fund. Z.C.'s team was also partly supported by the Theme-Based Research Scheme (T11-706/18-N).


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , CD8-Positive T-Lymphocytes , COVID-19/epidemiology , COVID-19/prevention & control , Hong Kong/epidemiology , Humans , Immunity , SARS-CoV-2/genetics , Vaccination
4.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336861

ABSTRACT

Summary The ongoing outbreak of SARS-CoV-2 Omicron BA.2 infections in Hong Kong, the world model city of universal masking, has resulted in a major public health crisis. In this study, we investigate public servants who had been vaccinated with two dose (82.7%) or three dose (14%) of either CoronaVac (CorV) or BNT162b2 (BNT). During the BA.2 outbreak, 29.3% vaccinees were infected. Three-dose vaccination provided protection with lower incidence rates of breakthrough infections (2×BNT 49.2% vs 3×BNT 16.6%, p <0.0001;2×CorV 48.6% vs 3×CoV 20.6%, p =0.003). The third heterologous vaccination showed the lowest incidence (2×CorV+1×BNT 6.3%). Although BA.2 conferred the highest neutralization resistance compared with variants of concern tested, the third dose vaccination-activated spike-specific memory B and Omicron cross-reactive T cell responses contributed to reduced frequencies of breakthrough infection and disease severity. Our results have implications to timely boost vaccination and immune responses likely required for vaccine-mediated protection against Omicron BA.2 pandemic.

5.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336856

ABSTRACT

1. Background Waning of protection against emerging SARS-CoV-2 variants by pre-existing antibodies elicited due to current vaccination or natural infection is a global concern. Whether this is due to waning of immunity to SARS-COV-2 remains unclear. Aim We aimed to investigate dynamics of antibody isotype responses among vaccinated naïve (VN) and naturally infected (NI) individuals. Methods We followed up antibody levels in COVID-19 mRNA-vaccinated subjects without prior infection (VN, n=100) at two phases: phase-I (P-I) at ∼1.4 and phase-II (P-II) at ∼5.3 months. Antibody levels were compared to those of unvaccinated and naturally infected subjects (NI, n=40) at ∼1.7 (P-1) and 5.2 (P-II) months post-infection. Neutralizing antibodies (NTAb), anti-S-RBD-IgG, -IgM, and anti-S-IgA isotypes were measured. Results VN group produced significantly greater antibody responses ( p <0.001) than NI group at P-I except for IgM. In VN group, a significant waning in antibody response was observed in all isotypes. There was about ∼ a 4-fold decline in NTAb levels ( p <0.001), anti-S-RBD-IgG (∼5-folds, p <0.001), anti-S-RBD-IgM (∼6-folds, p <0.001), and anti-S1-IgA (2-folds, p <0.001). In NI group, a significant but less steady decline was notable in NTAb (∼1-folds, p <0.001), anti-S-RBD IgG (∼1-fold, p =0.005), and S-RBD-IgM (∼2-folds, p <0.001). Unlike VN group, NI group mounted a lasting anti-S1-IgA response with no significant decline. Anti-S1-IgA levels which were ∼3 folds higher in VN subjects compared to NI in P-1 ( p <0.001), dropped to almost same levels, with no significant difference observed between the two groups in P-II. Conclusion While double dose mRNA vaccination boosted antibody levels, this “boost” was relatively short-lived in vaccinated individuals.

6.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336250

ABSTRACT

Background: The ongoing outbreak of SARS-CoV-2 Omicron BA.2 infections in Hong Kong, the world model city of universal masking, has resulted in a major public health crisis. Although the third heterologous BNT162b2 vaccination after 2-dose CoronaVac generated higher neutralizing antibody responses than the third homologous CoronaVac booster, vaccine efficacy and corelates of immune protection against the major circulating Omicron BA.2 remains to be investigated. Methods: : We investigated the vaccine efficacy against the Omicron BA.2 breakthrough infection among 481 public servants who had been received with SARS-CoV-2 vaccines including two-dose BNT162b2 (2×BNT, n=169), three-dose BNT162b2 (2×BNT, n=175), two-dose CoronaVac (2×CorV, n=37), three-dose CoronaVac (3×CorV, n=68) and third-dose BNT162b2 following 2×CorV (2×CorV+1BNT, n=32). Humoral and cellular immune responses after three-dose vaccination were characterized and correlated with clinical characteristics of BA.2 infection. Results: : During the BA.2 outbreak, 29.3% vaccinees were infected. Three-dose vaccination provided protection with lower incidence rates of breakthrough infections (2×BNT 49.2% vs 3×BNT 16.6%, p<0.0001;2×CorV 48.6% vs 3×CoV 20.6%, p=0.003). The third heterologous vaccination showed the lowest incidence (2×CorV+1×BNT 6.3%). Although BA.2 conferred the highest neutralization resistance compared with variants of concern tested, the third dose vaccination-activated spike-specific memory B and Omicron cross-reactive T cell responses contributed to reduced frequencies of breakthrough infection and disease severity. Conclusions: : Our results have implications to timely boost vaccination and immune responses likely required for vaccine-mediated protection against Omicron BA.2 pandemic.

7.
Chemical Engineering Journal ; : 136716, 2022.
Article in English | ScienceDirect | ID: covidwho-1814230

ABSTRACT

Recently, antibacterial coatings have gained great attention after the outbreak of COVID-19, thus durable transparent polyurethane (PU) coatings with anti-bacterial and anti-fingerprint performances are highly desired. In this work, the low surface free energy enables the hydroxyl-terminated polysiloxanes modified with quaternary ammonium salts (PQMS) enriched on the surface. The optimal PU-PQMS-40% coating with the thickness of 15 μm displayed 96% light transmittance and can be adopted to diverse substrates. This resultant coating exhibits excellent antibacterial activity against Gram-negative E. coli (99.2%) and Gram-positive S. aureus (98.6%) because of the synergistically enhanced antibacterial mechanism of both low surface free energy (27.54 ± 0.75 mJ·m−2) and quaternary ammonium salts (QAs). It is noteworthy that this antibacterial PU coating is capable of retaining its properties even after being subjected to 210 cycles of abrasion tests, manifesting a superior self-renewability. This coating system with combined features of transparency, antibacterial performance, chemical resistance, and durability make it a promising candidate for applications in the fields of electronic devices, automobile interiors, intelligent glass, and marine antifouling.

8.
Int J Infect Dis ; 118: 132-137, 2022 May.
Article in English | MEDLINE | ID: covidwho-1757407

ABSTRACT

BACKGROUND: A vast majority of the commercially available lateral flow immunoassay (LFIA) is used to detect SARS-CoV-2 antibodies qualitatively. Recently, a novel fluorescence-based lateral flow immunoassay (LFIA) test was developed for quantitative measurement of the total binding antibody units (BAUs) (BAU/mL) against SARS-CoV-2 spike protein receptor-binding domain (S-RBD). AIM: This study aimed to evaluate the performance of the fluorescence LFIA FinecareTM 2019-nCoV S-RBD test along with its reader (Model No.: FS-113). METHODS: Plasma from 150 reverse trancriptase-PCR (RT-PCR)-confirmed positive individuals and 100 prepandemic samples were tested by FincareTM to access sensitivity and specificity. For qualitative and quantitative validation of the FinCareTM measurements, BAU/mL results of FinCareTM were compared with results of 2 reference assays: the surrogate virus-neutralizing test (sVNT, GenScript Biotech, USA) and the VIDAS®3 automated assay (BioMérieux, France). RESULTS: FinecareTM showed 92% sensitivity and 100% specificity compared with PCR. Cohen's Kappa statistic denoted moderate and excellent agreement with sVNT and VIDAS®3, with values being 0.557 (95% CI: 0.32-0.78) and 0.731 (95% CI: 0.51-0.95), respectively. A strong correlation was observed between FinecareTM/sVNT (r = 0.7, p < 0.0001) and FinecareTM/VIDAS®3 (r = 0.8, p < 0.0001). CONCLUSION: FinecareTM is a reliable assay and can be used as a surrogate to assess binding and neutralizing antibody response after infection or vaccination, particularly in none or small laboratory settings.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/diagnosis , Humans , Immunoassay/methods , Sensitivity and Specificity , Spike Glycoprotein, Coronavirus
9.
Ther Adv Respir Dis ; 16: 17534666221087847, 2022.
Article in English | MEDLINE | ID: covidwho-1759662

ABSTRACT

BACKGROUND: During the novel coronavirus disease 2019 (COVID-19) pandemic raging around the world, the effectiveness of respiratory support treatment has dominated people's field of vision. This study aimed to compare the effectiveness and value of high-flow nasal cannula (HFNC) with noninvasive ventilation (NIV) for COVID-19 patients. METHODS: A comprehensive systematic review via PubMed, Web of Science, Cochrane, Scopus, WHO database, China Biology Medicine Disc (SINOMED), and China National Knowledge Infrastructure (CNKI) databases was conducted, followed by meta-analysis. RevMan 5.4 was used to analyze the results and risk of bias. The primary outcome is the number of deaths at day 28. The secondary outcomes are the occurrence of invasive mechanical ventilation (IMV), the number of deaths (no time-limited), length of intensive care unit (ICU) and hospital stay, ventilator-free days, and oxygenation index [partial pressure of arterial oxygen (PaO2)/fraction of inhaled oxygen (FiO2)] at 24 h. RESULTS: In total, nine studies [one randomized controlled trial (RCT), seven retrospective studies, and one prospective study] totaling 1582 patients were enrolled in the meta-analysis. The results showed that the incidence of IMV, number of deaths (no time-limited), and length of ICU stay were not statistically significant in the HFNC group compared with the NIV group (ps = 0.71, 0.31, and 0.33, respectively). Whereas the HFNC group performed significant advantages in terms of the number of deaths at day 28, length of hospital stay and oxygenation index (p < 0.05). Only in the ventilator-free days did NIV show advantages over the HFNC group (p < 0.0001). CONCLUSION: For COVID-19 patients, the use of HFNC therapy is associated with the reduction of the number of deaths at day 28 and length of hospital stay, and can significantly improve oxygenation index (PaO2/FiO2) at 24 h. However, there was no favorable between the HFNC and NIV groups in the occurrence of IMV. NIV group was superior only in terms of ventilator-free days.


Subject(s)
COVID-19 , Noninvasive Ventilation , Respiratory Insufficiency , COVID-19/therapy , Cannula , Humans , Noninvasive Ventilation/adverse effects , Noninvasive Ventilation/methods , Oxygen Inhalation Therapy/adverse effects , Oxygen Inhalation Therapy/methods , Randomized Controlled Trials as Topic , Respiration, Artificial , Respiratory Insufficiency/therapy
10.
Bioelectrochemistry ; 146: 108105, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-1748204

ABSTRACT

Serological antigen testing has emerged as an important diagnostic paradigm in COVID-19, but often suffers from potential cross-reactivity. To address this limitation, we herein report a label-free electrochemical aptamer-based sensor for the detection of SARS-CoV-2 antigen by integrating aptamer-based specific recognition with CRISPR-Cas12a-mediated signal amplification. The sensing principle is based on the competitive binding of antigen and the preassembled Cas12a-crRNA complex to the antigen-specific aptamer, resulting in a change in the collateral cleavage activity of Cas12a. To further generate an electrochemical signal, a DNA architecture was fabricated by in situ rolling circle amplification on a gold electrode, which serves as a novel substrate for Cas12a. Upon Cas12a-based collateral DNA cleavage, the DNA architecture was degraded, leading to a significant decrease in impedance that can be measured spectroscopically. Using SARS-CoV-2 nucleocapsid antigen as the model, the proposed CRISPR-Cas12a-based electrochemical sensor (CRISPR-E) showed excellent analytical performance for the quantitative detection of nucleocapsid antigen. Since in vitro selection can obtain aptamers selective for many SARS-CoV-2 antigens, the proposed strategy can expand this powerful CRISPR-E system significantly for quantitative monitoring of a wide range of COVID-19 biomarkers.


Subject(s)
Biosensing Techniques , COVID-19 , Biosensing Techniques/methods , COVID-19/diagnosis , CRISPR-Cas Systems , DNA , Humans , Nucleic Acid Amplification Techniques/methods , SARS-CoV-2/genetics
11.
Sustainability ; 14(4):2411, 2022.
Article in English | MDPI | ID: covidwho-1699772

ABSTRACT

This study aims to explore the changes of Chinese coronavirus disease-2019 (COVID-19) policy topics in the eclipse, outbreak, and convalescent stage of COVID-19 based on 4982 textual policies. By using the co-occurrence clustering network method, we find that the strict prevention and control of the epidemic is the only topic of policies in the eclipse stage. In the outbreak stage, strict epidemic prevention and control is still the most important policy topic. The policies of resuming work of “essential”enterprises and stabilizing market prices are important support and guarantee for fighting against COVID-19. In the convalescent stage, as the prevention and control of COVID-19 has become regular, promoting and ensuring the resumption of work in all sectors of society is the most important topic of the policies. Moreover, the success of Wuhan City’s fight against COVID-19 reflects China’s governance characteristics of “concentrating power to do a major event”. Finally, the possible improvements for Chinese COVID-19 policies are discussed, which can provide practical suggestions for government departments on how to effectively respond to public health emergencies.

12.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-315651

ABSTRACT

Coronavirus Disease 2019 (COVID-19)–infected pneumonia (CDIP) occurred in Wuhan, China, in December 2019, from where the disease has spread all over the world. Although the morbidity and mortality in China have been effectively controlled, the number of cases has increased rapidly in countries other than China. Here we report the epidemiological and clinical characteristics of 7 CDIP patients. We found that similar with the throat swabs, sputum induction still has a false negative rate. In addition, CD4+ count rise occurred before the disease remission, and decreased CD4+ count may be the cause of virus recurrence. These imply that CD4+ count could be a marker for recover and reinfection. Notably, we tentatively speculate that CD4+ plays a key role in the body's resistance to the COVID-19 attack on lung tissue.

13.
Int J Environ Res Public Health ; 19(3)2022 01 23.
Article in English | MEDLINE | ID: covidwho-1686727

ABSTRACT

PURPOSE: To investigate the compliance rates of health-related behaviors among Chinese preschool children, and to explore how supportive family environment, parental behavior, sociodemographic and community factors affect children's health-related behavior comprehensively. METHOD: Preschool children aged 3 to 6 years were chosen from 5760 villages (residential) committees from 471 counties (districts) of 31 provinces by use of a stratified random sampling procedure, with 10,967 preschool children aged 3-6 years old included. The survey was conducted from September 2020 to November 2020. RESULTS: The proportion of Chinese preschool children who met the moderate to vigorous physical activity (MVPA), screen time behavior (ST), and sleep behavior (SLP) guidelines were 62.3%, 52.8%, and 53.8%. Among the supportive family environment factors, parents' time with their children on weekends had the most significant impact on children's MVPA, ST, and SLP, with the odds ratio (OR) values of 2.18 (95%CI:1.97, 2.40), 0.69 (0.63, 0.76), and 1.62 (1.48, 1.79), respectively. Among the parental behavior factors, the mother's exercise frequency had a strong association with the children's MVPA and SLP, with OR values of 1.65 (1.50, 1.83) and 1.24 (1.13, 1.37), respectively; the mother's screen time was inversely associated with the children's ST with an OR value of 0.47 (0.44, 0.51). CONCLUSIONS: Different types of family environments were associated with the different levels of MVPA, ST and SLP among Chinese preschool children. In addition to the influence of parents' education and family income, parents could also improve their children's behaviors by providing a supportive family environment. The more of these factors presented in a family, the more likely it was for children to meet the guidelines. Therefore, for those families whose children's health-related behaviors needed to be improved, the parents should create supportive family environments, such as by playing less on mobile phone and spending more time with children.


Subject(s)
Exercise , Health Behavior , Child , Child, Preschool , Cross-Sectional Studies , Humans , Screen Time , Surveys and Questionnaires
14.
Frontiers in psychology ; 12, 2021.
Article in English | EuropePMC | ID: covidwho-1651972

ABSTRACT

The continuous increase of carbon emissions is a serious challenge all over the world, and many countries are striving to solve this problem. Since 2020, a widespread lockdown in the country to prevent the spread of COVID-19 escalated, severely restricting the movement of people and unnecessary economic activities, which unexpectedly reduced carbon emissions. This paper aims to analyze the carbon emissions data of 30 provinces in the 2020 and provide references for reducing emissions with epidemic lockdown measures. Based on the method of time series visualization, we transform the time series data into complex networks to find out the hidden information in these data. We found that the lockdown would bring about a short-term decrease in carbon emissions, and most provinces have a short time point of impact, which is closely related to the level of economic development and industrial structure. The current results provide some insights into the evolution of carbon emissions under COVID-19 blockade measures and valuable insights into energy conservation and response to the energy crisis in the post-epidemic era.

16.
Nat Cell Biol ; 24(1): 24-34, 2022 01.
Article in English | MEDLINE | ID: covidwho-1625709

ABSTRACT

SARS-CoV-2 infection of human cells is initiated by the binding of the viral Spike protein to its cell-surface receptor ACE2. We conducted a targeted CRISPRi screen to uncover druggable pathways controlling Spike protein binding to human cells. Here we show that the protein BRD2 is required for ACE2 transcription in human lung epithelial cells and cardiomyocytes, and BRD2 inhibitors currently evaluated in clinical trials potently block endogenous ACE2 expression and SARS-CoV-2 infection of human cells, including those of human nasal epithelia. Moreover, pharmacological BRD2 inhibition with the drug ABBV-744 inhibited SARS-CoV-2 replication in Syrian hamsters. We also found that BRD2 controls transcription of several other genes induced upon SARS-CoV-2 infection, including the interferon response, which in turn regulates the antiviral response. Together, our results pinpoint BRD2 as a potent and essential regulator of the host response to SARS-CoV-2 infection and highlight the potential of BRD2 as a therapeutic target for COVID-19.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/pharmacology , Epithelial Cells/virology , SARS-CoV-2/metabolism , Transcription Factors/drug effects , Angiotensin-Converting Enzyme 2/drug effects , COVID-19/drug therapy , COVID-19/metabolism , COVID-19/virology , Cell Line , Epithelial Cells/metabolism , Humans , Membrane Glycoproteins/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity , Transcription Factors/metabolism
17.
J Med Chem ; 65(1): 876-884, 2022 01 13.
Article in English | MEDLINE | ID: covidwho-1606194

ABSTRACT

Coronavirus disease 2019 (COVID-19) pandemic, a global health threat, was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 papain-like cysteine protease (PLpro) was recognized as a promising drug target because of multiple functions in virus maturation and antiviral immune responses. Inhibitor GRL0617 occupied the interferon-stimulated gene 15 (ISG15) C-terminus-binding pocket and showed an effective antiviral inhibition. Here, we described a novel peptide-drug conjugate (PDC), in which GRL0617 was linked to a sulfonium-tethered peptide derived from PLpro-specific substrate LRGG. The EM-C and EC-M PDCs showed a promising in vitro IC50 of 7.40 ± 0.37 and 8.63 ± 0.55 µM, respectively. EC-M could covalently label PLpro active site C111 and display anti-ISGylation activities in cellular assays. The results represent the first attempt to design PDCs composed of stabilized peptide inhibitors and GRL0617 to inhibit PLpro. These novel PDCs provide promising opportunities for antiviral drug design.


Subject(s)
Aniline Compounds/chemistry , Antiviral Agents/metabolism , Benzamides/chemistry , Coronavirus Papain-Like Proteases/metabolism , Drug Design , Naphthalenes/chemistry , Peptides/chemistry , SARS-CoV-2/enzymology , Aniline Compounds/metabolism , Aniline Compounds/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Benzamides/metabolism , Benzamides/pharmacology , COVID-19/drug therapy , COVID-19/pathology , COVID-19/virology , Cell Line , Cell Survival/drug effects , Coronavirus Papain-Like Proteases/chemistry , Cytokines/chemistry , Drug Evaluation, Preclinical , Humans , Inhibitory Concentration 50 , Naphthalenes/metabolism , Naphthalenes/pharmacology , SARS-CoV-2/isolation & purification , Ubiquitins/chemistry
18.
Biosens Bioelectron ; 201: 113944, 2022 Apr 01.
Article in English | MEDLINE | ID: covidwho-1588207

ABSTRACT

Coronavirus Disease 2019 (COVID-19), which poses an extremely serious global impact on human public healthcare, represents a high transmission and disease-causing viral infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is expanding at a rapid pace. Therefore, it is urgent for researchers to establish effective platforms for the assay and treatment of SARS-CoV-2. Functional nucleic acids (FNAs), comprising aptamers and nucleases, are of primary concern within the biological and medical communities owing of the distinctive properties of their target recognition and catalysis. This review will concentrate on the essential aspects of insights regarding FNAs and their technological expertise for the diagnostic and therapeutic utilization against COVID-19. We first offer a historical perspective of the COVID-19 pandemics, its clinical characteristics and potential biomarkers. Then, we briefly discuss the current diagnostic and therapeutic methodology towards COVID-19, highlighting the superiorities and existing shortcomings. After that, we introduce the key features of FNAs, and summarize recent progress of in vitro selection of FNAs for SARS-CoV-2 specific proteins and RNAs, followed by highlighting the general concept of translating FNAs into functional probes for diagnostic and therapeutic purposes. Then, we critically review the emerging FNAs-based diagnostic and therapeutic strategies that are fast, precise, efficient, and highly specific to fight COVID-19. Finally, we identify remaining challenges and offer future outlook of this emerging field.


Subject(s)
Biosensing Techniques , COVID-19 , Nucleic Acids , Humans , Nucleic Acids/genetics , Pandemics , SARS-CoV-2
19.
EBioMedicine ; 75: 103762, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1587929

ABSTRACT

BACKGROUND: Vaccines in emergency use are efficacious against COVID-19, yet vaccine-induced prevention against nasal SARS-CoV-2 infection remains suboptimal. METHODS: Since mucosal immunity is critical for nasal prevention, we investigated the efficacy of an intramuscular PD1-based receptor-binding domain (RBD) DNA vaccine (PD1-RBD-DNA) and intranasal live attenuated influenza-based vaccines (LAIV-CA4-RBD and LAIV-HK68-RBD) against SARS-CoV-2. FINDINGS: Substantially higher systemic and mucosal immune responses, including bronchoalveolar lavage IgA/IgG and lung polyfunctional memory CD8 T cells, were induced by the heterologous PD1-RBD-DNA/LAIV-HK68-RBD as compared with other regimens. When vaccinated animals were challenged at the memory phase, prevention of robust SARS-CoV-2 infection in nasal turbinate was achieved primarily by the heterologous regimen besides consistent protection in lungs. The regimen-induced antibodies cross-neutralized variants of concerns. Furthermore, LAIV-CA4-RBD could boost the BioNTech vaccine for improved mucosal immunity. INTERPRETATION: Our results demonstrated that intranasal influenza-based boost vaccination induces mucosal and systemic immunity for effective SARS-CoV-2 prevention in both upper and lower respiratory systems. FUNDING: This study was supported by the Research Grants Council Collaborative Research Fund, General Research Fund and Health and Medical Research Fund in Hong Kong; Outbreak Response to Novel Coronavirus (COVID-19) by the Coalition for Epidemic Preparedness Innovations; Shenzhen Science and Technology Program and matching fund from Shenzhen Immuno Cure BioTech Limited; the Health@InnoHK, Innovation and Technology Commission of Hong Kong; National Program on Key Research Project of China; donations from the Friends of Hope Education Fund; the Theme-Based Research Scheme.


Subject(s)
COVID-19 Vaccines , COVID-19/prevention & control , Immunization, Secondary , Influenza Vaccines , SARS-CoV-2 , Vaccines, DNA , Administration, Intranasal , Animals , COVID-19/genetics , COVID-19/immunology , COVID-19 Vaccines/genetics , COVID-19 Vaccines/immunology , Chlorocebus aethiops , Disease Models, Animal , Dogs , Female , HEK293 Cells , Humans , Immunity, Mucosal , Influenza Vaccines/genetics , Influenza Vaccines/immunology , Madin Darby Canine Kidney Cells , Male , Mice , Mice, Inbred BALB C , Mice, Transgenic , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Vaccines, Attenuated/genetics , Vaccines, Attenuated/immunology , Vaccines, DNA/genetics , Vaccines, DNA/immunology , Vero Cells
20.
Foods ; 10(9)2021 Sep 12.
Article in English | MEDLINE | ID: covidwho-1409088

ABSTRACT

Since COVID-19 was first detected in China in 2019, governments around the world have imposed strict measures to curb the spread of the coronavirus, which substantially impacted people's life. Consumers' food consumption behavior has also changed accordingly with reduced grocery shopping frequency, replaced in-person grocery shopping with online shopping, and increased valuation on food. In this paper, we aim to investigate the change in Chinese consumers' food consumption and their willingness to pay (WTP) for vegetables and meat, using a dataset with 1206 online samples collected between February and March 2020. Consumers' WTP for vegetables and meat is estimated using a double-bounded dichotomous contingent valuation design, and factors affecting their WTPs are also investigated. Results show that consumers have a higher WTP for these food products during the pandemic, and their WTP is positively affected by their anticipated duration of the COVID-19, their online shopping shares, their direct exposure to infected patients, their gender, and their income. These results imply that the food industry shall try to develop online market channels as consumers are willing to share the costs, while lower-income consumers may not be able to meet their food needs with prices increased beyond their WTP and thus may call for the government's support.

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