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1.
PeerJ Computer Science ; 2022.
Article in English | ProQuest Central | ID: covidwho-1994469

ABSTRACT

Most stock price predictive models merely rely on the target stock’s historical information to forecast future prices, where the linkage effects between stocks are neglected. However, a group of prior studies has shown that the leverage of correlations between stocks could significantly improve the predictions. This article proposes a unified time-series relational multi-factor model (TRMF), which composes a self-generating relations (SGR) algorithm that can extract relational features automatically. In addition, the TRMF model integrates stock relations with other multiple dimensional features for the price prediction compared to extant works. Experimental validations are performed on the NYSE and NASDAQ data, where the model is compared with the popular methods such as attention Long Short-Term Memory network (Attn-LSTM), Support Vector Regression (SVR), and multi-factor framework (MF). Results show that compared with these extant methods, our model has a higher expected cumulative return rate and a lower risk of return volatility.

2.
Biosci Trends ; 16(3): 242-244, 2022 Jul 20.
Article in English | MEDLINE | ID: covidwho-1964373

ABSTRACT

As a new variant of COVID-19 with varied mutations, Omicron is more transmissible, more rapidly contagious, and has a greater risk of reinfection. Given those facts, a precise manage strategy needs to be formulated and implemented in designated megacities. Here, the precise COVID-19 prevention and control strategy for a designated hospital in Shenzhen, China is summarized, including implementation of a two-wing "On duty/On standby" approach based on busy and calm periods, an identification, classification, and grading system for the occupational exposure risks of medical staff, classification of patient transmission risks, separate admission, and an innovative treatment (nasal irrigation). The strategy has enabled the efficient and orderly integration of resources, it has resulted in zero infections among medical staff even during the peak hours of the pandemic at the hospital (1,930 patients admitted to both wings in a single day), and it has significantly reduced the initial period of no virus detection when patients infected with Omicron received saline nasal irrigation (P < 0.001). This strategy has provided evidence of precise prevention and control in a hospital, infection control, and efficient patient treatment in an era when Omicron is widespread.


Subject(s)
COVID-19 , Cities , Hospitals , Humans , Infection Control , Pandemics/prevention & control
3.
JMIR Form Res ; 6(7): e40365, 2022 Jul 06.
Article in English | MEDLINE | ID: covidwho-1963271

ABSTRACT

[This corrects the article DOI: 10.2196/30371.].

4.
Frontiers in immunology ; 13, 2022.
Article in English | EuropePMC | ID: covidwho-1918699

ABSTRACT

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is one of the fastest-evolving viral diseases that has instigated a worldwide pandemic. Severe inflammatory syndrome and venous thrombosis are commonly noted in COVID-19 patients with severe and critical illness, contributing to the poor prognosis. Interleukin (IL)-6, a major complex inflammatory cytokine, is an independent factor in predicting the severity of COVID-19 disease in patients. IL-6 and tumor necrosis factor (TNF)-α participate in COVID-19-induced cytokine storm, causing endothelial cell damage and upregulation of plasminogen activator inhibitor-1 (PAI-1) levels. In addition, IL-6 and PAI-1 form a vicious cycle of inflammation and thrombosis, which may contribute to the poor prognosis of patients with severe COVID-19. Targeted inhibition of IL-6 and PAI-1 signal transduction appears to improve treatment outcomes in severely and critically ill COVID-19 patients suffering from cytokine storms and venous thrombosis. Motivated by studies highlighting the relationship between inflammatory cytokines and thrombosis in viral immunology, we provide an overview of the immunothrombosis and immunoinflammation vicious loop between IL-6 and PAI-1. Our goal is that understanding this ferocious circle will benefit critically ill patients with COVID-19 worldwide.

5.
Emerg Microbes Infect ; 11(1): 1890-1899, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1915484

ABSTRACT

The efficacy of many coronavirus disease 2019 (COVID-19) vaccines has been shown to decrease to varying extents against new severe acute respiratory syndrome coronavirus 2 variants, which are responsible for the continuing COVID-19 pandemic. Combining intramuscular and intranasal vaccination routes is a promising approach for achieving more potent immune responses. We evaluated the immunogenicity of prime-boost protocols with a chimpanzee adenovirus serotype 68 vector-based vaccine, ChAdTS-S, administered via both intranasal and intramuscular routes in BALB/c mice. Intramuscular priming followed by an intranasal booster elicited the highest levels of IgG, IgA, and pseudovirus neutralizing antibody titres among all the protocols tested at day 42 after prime immunization compared with the intranasal priming/intramuscular booster and prime-boost protocols using only one route. In addition, intramuscular priming followed by an intranasal booster induced high T-cell responses, measured using the IFN-γ ELISpot assay, that were similar to those observed upon intramuscular vaccination. All ChAdTS-S vaccination groups induced Th1-skewing of the T-cell response according to intracellular cytokine staining and Meso Scale Discovery cytokine profiling assays on day 56 after priming. This study provides reference data for assessing vaccination schemes of adenovirus-based COVID-19 vaccines with high immune efficacy.


Subject(s)
COVID-19 Vaccines , COVID-19 , Adenoviridae/genetics , Animals , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines/immunology , Cytokines , Immunity, Cellular , Immunity, Humoral , Immunization, Secondary , Mice , Mice, Inbred BALB C , Pan troglodytes , SARS-CoV-2 , Vaccination
6.
JMIR Form Res ; 6(5): e30371, 2022 05 30.
Article in English | MEDLINE | ID: covidwho-1875269

ABSTRACT

BACKGROUND: The COVID-19 pandemic exacerbated existing racial/ethnic health disparities in the United States. Monitoring nationwide Twitter conversations about COVID-19 and race/ethnicity could shed light on the impact of the pandemic on racial/ethnic minorities and help address health disparities. OBJECTIVE: This paper aims to examine the association between COVID-19 tweet volume and COVID-19 cases and deaths, stratified by race/ethnicity, in the early onset of the pandemic. METHODS: This cross-sectional study used geotagged COVID-19 tweets from within the United States posted in April 2020 on Twitter to examine the association between tweet volume, COVID-19 surveillance data (total cases and deaths in April), and population size. The studied time frame was limited to April 2020 because April was the earliest month when COVID-19 surveillance data on racial/ethnic groups were collected. Racially/ethnically stratified tweets were extracted using racial/ethnic group-related keywords (Asian, Black, Latino, and White) from COVID-19 tweets. Racially/ethnically stratified tweets, COVID-19 cases, and COVID-19 deaths were mapped to reveal their spatial distribution patterns. An ordinary least squares (OLS) regression model was applied to each stratified dataset. RESULTS: The racially/ethnically stratified tweet volume was associated with surveillance data. Specifically, an increase of 1 Asian tweet was correlated with 288 Asian cases (P<.001) and 93.4 Asian deaths (P<.001); an increase of 1 Black tweet was linked to 47.6 Black deaths (P<.001); an increase of 1 Latino tweet was linked to 719 Latino deaths (P<.001); and an increase of 1 White tweet was linked to 60.2 White deaths (P<.001). CONCLUSIONS: Using racially/ethnically stratified Twitter data as a surveillance indicator could inform epidemiologic trends to help estimate future surges of COVID-19 cases and potential future outbreaks of a pandemic among racial/ethnic groups.

7.
Lancet Respir Med ; 10(8): 749-760, 2022 08.
Article in English | MEDLINE | ID: covidwho-1867947

ABSTRACT

BACKGROUND: All currently available SARS-CoV-2 vaccines are administered by intramuscular injection. We aimed to evaluate the safety and immunogenicity of a live-attenuated influenza virus vector-based SARS-CoV-2 vaccine (dNS1-RBD) administered by intranasal spray in healthy adults. METHODS: We did double-blind, randomised, placebo-controlled phase 1 and 2 trials, followed by a phase 2 extension trial, at a single centre in Jiangsu, China. Healthy adults (≥18 years) who had negative serum or fingertip blood total antibody tests for SARS-CoV-2 (in phases 1 and 2), with no prevalent SARS-CoV-2 infection or history of infection and no SARS-CoV-2 vaccination history (in all three trials reported here), were enrolled. Participants were randomly allocated (4:1 in phase 1, 2:1 in phase 2, and 1:1 in the extension trial) to receive two intranasal doses of the dNS1-RBD vaccine or placebo on days 0 and 14 or, for half of the participants in phase 2, on days 0 and 21. To avoid cross-contamination during administration, vaccine and placebo recipients were vaccinated in separate rooms in the extension trial. The phase 1 primary outcome was safety (adverse events recorded on days 0-44; serious adverse events recorded from day 0 until 12 months after the second dose). In the phase 2 and extension trials, the primary immunogenicity outcomes were SARS-CoV-2-specific T-cell response in peripheral blood (measured by IFN-γ ELISpot), proportion of participants with positive conversion for SARS-CoV-2 receptor-binding domain (RBD)-specific IgG and secretory IgA (s-IgA) antibodies, and concentration of SARS-CoV-2 RBD IgG in serum and SARS-CoV-2 RBD s-IgA in the nasopharynx (measured by ELISA) at 1 month after the second dose in the per-protocol set for immunogenicity. χ2 test and Fisher's exact test were used to analyse categorical data, and t test and Wilcoxon rank sum test to compare the measurement data between groups. These trials were registered with the Chinese Clinical Trial Registry (ChiCTR2000037782, ChiCTR2000039715, and ChiCTR2100048316). FINDINGS: Between Sept 1, 2020, and July 4, 2021, 63, 724, and 297 participants without a history of SARS-CoV-2 vaccination were enrolled in the phase 1, phase 2, and extension trials, respectively. At least one adverse reaction after vaccination was reported in 133 (19%) of 684 participants in the vaccine groups. Most adverse reactions were mild. No vaccine-related serious adverse event was noted. Specific T-cell immune responses were observed in 211 (46% [95% CI 42-51]) of 455 vaccine recipients in the phase 2 trial, and in 48 (40% [31-49]) of 120 vaccine recipients compared with one (1% [0-5]) of 111 placebo recipients (p<0·0001) in the extension trial. Seroconversion for RBD-specific IgG was observed in 48 (10% [95% CI 8-13]) of 466 vaccine recipients in the phase 2 trial (geometric mean titre [GMT] 3·8 [95% CI 3·4-4·3] in responders), and in 31 (22% [15-29]) of 143 vaccine recipients (GMT 4·4 [3·3-5·8]) and zero (0% [0-2]) of 147 placebo recipients (p<0·0001) in the extension trial. 57 (12% [95% CI 9-16]) of 466 vaccine recipients had positive conversion for RBD-specific s-IgA (GMT 3·8 [95% CI 3·5-4·1] in responders) in the phase 2 trial, as did 18 (13% [8-19]) of 143 vaccine recipients (GMT 5·2 [4·0-6·8]) and zero (0% [0-2]) of 147 placebo recipients (p<0·0001) in the extension trial. INTERPRETATION: dNS1-RBD was well tolerated in adults. Weak T-cell immunity in peripheral blood, as well as weak humoral and mucosal immune responses against SARS-CoV-2, were detected in vaccine recipients. Further studies are warranted to verify the safety and efficacy of intranasal vaccines as a potential supplement to current intramuscular SARS-CoV-2 vaccine pools. Steps should be taken in future studies to reduce the potential for cross-contamination caused by the vaccine strain aerosol during administration. FUNDING: National Key Research and Development Program of China, National Science, Fujian Provincial Science, CAMS Innovation Fund for Medical Sciences, and Beijing Wantai Biological Pharmacy Enterprise.


Subject(s)
COVID-19 Vaccines , COVID-19 , Orthomyxoviridae , Viral Vaccines , Adult , Antibodies, Viral , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Double-Blind Method , Humans , Immunoglobulin A , Immunoglobulin G , SARS-CoV-2 , Vaccines, Attenuated/adverse effects
8.
Sci Bull (Beijing) ; 67(13): 1372-1387, 2022 Jul 15.
Article in English | MEDLINE | ID: covidwho-1867754

ABSTRACT

Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, they are limited with respect to eliciting local immunity in the respiratory tract, which is the primary infection site for SARS-CoV-2. To overcome the limitations of intramuscular vaccines, we constructed a nasal vaccine candidate based on an influenza vector by inserting a gene encoding the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2, named CA4-dNS1-nCoV-RBD (dNS1-RBD). A preclinical study showed that in hamsters challenged 1 d after single-dose vaccination or 9 months after booster vaccination, dNS1-RBD largely mitigated lung pathology, with no loss of body weight. Moreover, such cellular immunity is relatively unimpaired for the most concerning SARS-CoV-2 variants, especially for the latest Omicron variant. In addition, this vaccine also provides cross-protection against H1N1 and H5N1 influenza viruses. The protective immune mechanism of dNS1-RBD could be attributed to the innate immune response in the nasal epithelium, local RBD-specific T cell response in the lung, and RBD-specific IgA and IgG response. Thus, this study demonstrates that the intranasally delivered dNS1-RBD vaccine candidate may offer an important addition to the fight against the ongoing coronavirus disease 2019 pandemic and influenza infection, compensating limitations of current intramuscular vaccines.

9.
Nat Metab ; 4(5): 547-558, 2022 05.
Article in English | MEDLINE | ID: covidwho-1830111

ABSTRACT

The severity and mortality of COVID-19 are associated with pre-existing medical comorbidities such as diabetes mellitus. However, the underlying causes for increased susceptibility to viral infection in patients with diabetes is not fully understood. Here we identify several small-molecule metabolites from human blood with effective antiviral activity against SARS-CoV-2, one of which, 1,5-anhydro-D-glucitol (1,5-AG), is associated with diabetes mellitus. The serum 1,5-AG level is significantly lower in patients with diabetes. In vitro, the level of SARS-CoV-2 replication is higher in the presence of serum from patients with diabetes than from healthy individuals and this is counteracted by supplementation of 1,5-AG to the serum from patients. Diabetic (db/db) mice undergo SARS-CoV-2 infection accompanied by much higher viral loads and more severe respiratory tissue damage when compared to wild-type mice. Sustained supplementation of 1,5-AG in diabetic mice reduces SARS-CoV-2 loads and disease severity to similar levels in nondiabetic mice. Mechanistically, 1,5-AG directly binds the S2 subunit of the SARS-CoV-2 spike protein, thereby interrupting spike-mediated virus-host membrane fusion. Our results reveal a mechanism that contributes to COVID-19 pathogenesis in the diabetic population and suggest that 1,5-AG supplementation may be beneficial to diabetic patients against severe COVID-19.


Subject(s)
COVID-19 , Diabetes Mellitus, Experimental , Animals , Glucose , Humans , Mice , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
10.
Front Microbiol ; 13: 828806, 2022.
Article in English | MEDLINE | ID: covidwho-1793005

ABSTRACT

The coronavirus disease 2019 (COVID-19) vaccines have very successfully decreased the disease risk as we know; some key information remains unknown due to the short development history and the lack of long-term follow-up studies in vaccinated populations. One of the unanswered issues is the protection duration conferred after COVID-19 vaccination, which appears to play a pivotal role in the future impact of pathogens and is critical to inform the public health response and policy decisions. Here, we review current information on the long-term effectiveness of different COVID-19 vaccines, persistence of immunogenicity, and gaps in knowledge. Meanwhile, we also discuss the influencing factors and future study prospects on this topic.

11.
Emerg Microbes Infect ; 11(1): 793-803, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1758587

ABSTRACT

The specific antibodies induced by SARS-CoV-2 infection may provide protection against a subsequent infection. However, the efficacy and duration of protection provided by naturally acquired immunity against subsequent SARS-CoV-2 infection remain controversial. We systematically searched for the literature describing COVID-19 reinfection published before 07 February 2022. The outcomes were the pooled incidence rate ratio (IRR) for estimating the risk of subsequent infection. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the included studies. Statistical analyses were conducted using the R programming language 4.0.2. We identified 19 eligible studies including more than 3.5 million individuals without the history of COVID-19 vaccination. The efficacy of naturally acquired antibodies against reinfection was estimated at 84% (pooled IRR = 0.16, 95% CI: 0.14-0.18), with higher efficacy against symptomatic COVID-19 cases (pooled IRR = 0.09, 95% CI = 0.07-0.12) than asymptomatic infection (pooled IRR = 0.28, 95% CI = 0.14-0.54). In the subgroup analyses, the pooled IRRs of COVID-19 infection in health care workers (HCWs) and the general population were 0.22 (95% CI = 0.16-0.31) and 0.14 (95% CI = 0.12-0.17), respectively, with a significant difference (P = 0.02), and those in older (over 60 years) and younger (under 60 years) populations were 0.26 (95% CI = 0.15-0.48) and 0.16 (95% CI = 0.14-0.19), respectively. The risk of subsequent infection in the seropositive population appeared to increase slowly over time. In conclusion, naturally acquired antibodies against SARS-CoV-2 can significantly reduce the risk of subsequent infection, with a protection efficacy of 84%.Registration number: CRD42021286222.


Subject(s)
COVID-19 , Aged , Asymptomatic Infections , COVID-19/prevention & control , COVID-19 Vaccines , Health Personnel , Humans , SARS-CoV-2
12.
Signal Transduct Target Ther ; 7(1): 94, 2022 03 23.
Article in English | MEDLINE | ID: covidwho-1758181

ABSTRACT

To date, the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has determined 399,600,607 cases and 5,757,562 deaths worldwide. COVID-19 is a serious threat to human health globally. The World Health Organization (WHO) has declared COVID-19 pandemic a major public health emergency. Vaccination is the most effective and economical intervention for controlling the spread of epidemics, and consequently saving lives and protecting the health of the population. Various techniques have been employed in the development of COVID-19 vaccines. Among these, the COVID-19 messenger RNA (mRNA) vaccine has been drawing increasing attention owing to its great application prospects and advantages, which include short development cycle, easy industrialization, simple production process, flexibility to respond to new variants, and the capacity to induce better immune response. This review summarizes current knowledge on the structural characteristics, antigen design strategies, delivery systems, industrialization potential, quality control, latest clinical trials and real-world data of COVID-19 mRNA vaccines as well as mRNA technology. Current challenges and future directions in the development of preventive mRNA vaccines for major infectious diseases are also discussed.


Subject(s)
COVID-19 Vaccines , COVID-19 , COVID-19/prevention & control , COVID-19 Vaccines/genetics , Humans , Pandemics/prevention & control , RNA, Messenger/genetics , SARS-CoV-2/genetics , Vaccines, Synthetic
13.
Frontiers in microbiology ; 13, 2022.
Article in English | EuropePMC | ID: covidwho-1733475

ABSTRACT

The coronavirus disease 2019 (COVID-19) vaccines have very successfully decreased the disease risk as we know;some key information remains unknown due to the short development history and the lack of long-term follow-up studies in vaccinated populations. One of the unanswered issues is the protection duration conferred after COVID-19 vaccination, which appears to play a pivotal role in the future impact of pathogens and is critical to inform the public health response and policy decisions. Here, we review current information on the long-term effectiveness of different COVID-19 vaccines, persistence of immunogenicity, and gaps in knowledge. Meanwhile, we also discuss the influencing factors and future study prospects on this topic.

14.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-315679

ABSTRACT

Background: Since the first case of pneumonia with unknown etiology was identified in Wuhan, Hubei province in China in December 2019, the novel coronavirus pneumonia has placed a serious impact on many aspects of the world. Note that the incubation period distribution plays important roles in prevention and control efforts of COVID-19. This study aimed to investigate the conditional distribution of the incubation period of COVID-19 on the age of infected cases, and estimate its corresponding quantiles from information of 2172 confirmed cases from 29 provinces outside Hubei in China. Methods: : We collected data including the infection dates, onset dates, and ages of the confirmed cases from the websites of the centres of disease control, or the daily public reports through February 16th, 2020. A maximum likelihood method was developed to account for the biased sampling issue of the data as the epidemic was still ongoing at the time of collecting data. Results: : Based on the collected data, we found that the conditional quantiles of the incubation period distribution of COVID-19 varies over ages. In detail, the high conditional quantiles of people in the middle age group are shorter than those of others. We estimated that the 0.95-th quantile related to people in the age group 23∼55 is less than 15 days. Conclusions: : Observing that the conditional quantiles vary over ages, we may take more precise measures for people of different ages. For example, we may consider carrying out an age-dependent quarantine duration, rather than a uniform 14-days quarantine, in practice. Remarkably, we may need to extend the current quarantine duration for people aged 0 ∼ 22 and over 55 because the related 0.95-th quantiles are much greater than 14 days.

15.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-315678

ABSTRACT

Background: In December 2019, some cases of pneumonia with unknown etiology were identified in Wuhan, Hubei province in China. The World Health Organization (WHO) has named this disease as COVID-19, standing for ``2019 coronavirus disease", and announced the disease have become a public health incident on December 31, 2019. This study aimed to investigate the conditional distribution of the incubation period of COVID-19 on the age of infected cases, and estimate its corresponding conditional quantiles from information on 2172 confirmed cases from 29 provinces outside Hubei in China. Methods : We collected data including the infection dates, onset dates, and ages of the confirmed cases from the websites of the centres of disease control, or the daily public reports through February 16th, 2020. A new maximum likelihood method was developed to account for the biased sampling, or right truncation, issue of the data as the epidemic is still ongoing. The estimators can be shown to be consistent asymptotically under mild conditions. Results : Based on the collected data, we found that the conditional quantiles of the incubation period distribution of COVID-19 varies over ages. In detail, the high conditional quantiles of people in the middle age group are shorter than those of others. We estimated that the 0.95-th quantile related to people in the age group 23$\sim$55 is less than 15 days. Conclusions : Observing that the conditional quantiles vary over ages, we may take more precise measures for people of different ages. For example, we may consider carrying out an age-dependent quarantine duration, rather than a uniform 14-days quarantine, in practice. Remarkably, we may need to extend the current quarantine duration for people aged $0\sim22$ and over 55 because the related 0.95-th quantiles are much greater than 14 days.

16.
Annals of Tourism Research ; 93:103365, 2022.
Article in English | ScienceDirect | ID: covidwho-1682899

ABSTRACT

During the COVID-19 pandemic, daily tourism demand forecasting provides actionable insight on tourism operations amid intense uncertainty. This paper applies the lasso method to predict daily tourism demand across 74 countries in 2020. We evaluate the usefulness of online search queries in boosting forecasting accuracy. The lasso method is used to select appropriate predictors and their lag orders. Results indicate that, in general, no evidence supports the usefulness of Google Trends data in generating more accurate forecasts. However, in some countries, the data can be useful for reducing the forecasting errors. Regression analysis further demonstrates that the relative usefulness of online search queries is associated with pandemic severity, the dominance of inbound tourism, and island geography. Lastly, implications are provided.

17.
Micromachines (Basel) ; 13(2)2022 Jan 18.
Article in English | MEDLINE | ID: covidwho-1625202

ABSTRACT

Purpose: This study aims to establish a competitive allele-specific PCR based on penta-primer amplification refractory mutation system (PARMS) technology to detect the key mutation sites of variant of concern (VOC) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus for rapid typing. Methods: Competitive allele-specific primers and universal primers were designed for the key gene mutation sites N501Y, E484K, L452R, and K417N of SARS-CoV-2 VOCs, respectively.Using the principle of allele-specific polymerase chain reaction and fluorescence energy resonance transfer, different VOCs can be differentiated. Results: Using reverse transcribed cDNA of different VOCs as specimens, through double-blind detection, different VOC types can be effectively identified, with an accuracy rate of 100%. Through the identification and detection of different VOCs, effective differentiation can be achieved. Conclusions: The system has high specificity and sensitivity, with a detection limit of 1.28 copies/reaction.PARMS technology is fast, efficient, and low-cost. It is used for the identification and detection of the popular SARS-CoV-2 VOCs, which is helpful for the rapid and accurate prevention and control of COVID-19 epidemic.

18.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-292884

ABSTRACT

Remarkable progress has been made in developing intramuscular vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2);however, they are limited with respect to eliciting local immunity in the respiratory tract, which is the primary infection site for SARS-CoV-2. To overcome the limitations of intramuscular vaccines, we constructed a nasal vaccine candidate based on an influenza vector by inserting a gene encoding the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2, named CA4-dNS1-nCoV-RBD (dNS1-RBD). A preclinical study showed that in hamsters challenged 1 day and 7 days after single-dose vaccination or 6 months after booster vaccination, dNS1-RBD largely mitigated lung pathology, with no loss of body weight, caused by either the prototype-like strain or beta variant of SARS-CoV-2. Lasted data showed that the animals could be well protected against beta variant challenge 9 months after vaccination. Notably, the weight loss and lung pathological changes of hamsters could still be significantly reduced when the hamster was vaccinated 24 h after challenge. Moreover, such cellular immunity is relatively unimpaired for the most concerning SARS-CoV-2 variants. The protective immune mechanism of dNS1-RBD could be attributed to the innate immune response in the nasal epithelium, local RBD-specific T cell response in the lung, and RBD-specific IgA and IgG response. Thus, this study demonstrates that the intranasally delivered dNS1-RBD vaccine candidate may offer an important addition to fight against the ongoing COVID-19 pandemic, compensating limitations of current intramuscular vaccines, particularly at the start of an outbreak.

19.
Inquiry ; 58: 469580211060259, 2021.
Article in English | MEDLINE | ID: covidwho-1528627

ABSTRACT

Evidence regarding the effects of environmental factors on COVID-19 transmission is mixed. We aimed to explore the associations of air pollutants and meteorological factors with COVID-19 confirmed cases during the outbreak period throughout China. The number of COVID-19 confirmed cases, air pollutant concentrations, and meteorological factors in China from January 25 to February 29, 2020, (36 days) were extracted from authoritative electronic databases. The associations were estimated for a single-day lag as well as moving averages lag using generalized additive mixed models. Region-specific analyses and meta-analysis were conducted in 5 selected regions from the north to south of China with diverse air pollution levels and weather conditions and sufficient sample size. Nonlinear concentration-response analyses were performed. An increase of each interquartile range in PM2.5, PM10, SO2, NO2, O3, and CO at lag4 corresponded to 1.40 (1.37-1.43), 1.35 (1.32-1.37), 1.01 (1.00-1.02), 1.08 (1.07-1.10), 1.28 (1.27-1.29), and 1.26 (1.24-1.28) ORs of daily new cases, respectively. For 1°C, 1%, and 1 m/s increase in temperature, relative humidity, and wind velocity, the ORs were 0.97 (0.97-0.98), 0.96 (0.96-0.97), and 0.94 (0.92-0.95), respectively. The estimates of PM2.5, PM10, NO2, and all meteorological factors remained significantly after meta-analysis for the five selected regions. The concentration-response relationships showed that higher concentrations of air pollutants and lower meteorological factors were associated with daily new cases increasing. Higher air pollutant concentrations and lower temperature, relative humidity and wind velocity may favor COVID-19 transmission. Controlling ambient air pollution, especially for PM2.5, PM10, NO2, may be an important component of reducing risk of COVID-19 infection. In addition, as winter months are arriving in China, the meteorological factors may play a negative role in prevention. Therefore, it is significant to implement the public health control measures persistently in case another possible pandemic.


Subject(s)
Air Pollutants , COVID-19 , Air Pollutants/adverse effects , Air Pollutants/analysis , China , Humans , Meteorological Concepts , SARS-CoV-2
20.
Emerg Microbes Infect ; 10(1): 365-375, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1490458

ABSTRACT

Concerns about vaccine safety are an important reason for vaccine hesitancy, however, limited information is available on whether common adverse reactions following vaccination affect the immune response. Data from three clinical trials of recombinant vaccines were used in this post hoc analysis to assess the correlation between inflammation-related solicited adverse reactions (ISARs, including local pain, redness, swelling or induration and systematic fever) and immune responses after vaccination. In the phase III trial of the bivalent HPV-16/18 vaccine (Cecolin®), the geometric mean concentrations (GMCs) for IgG anti-HPV-16 and -18 (P<0.001) were significantly higher in participants with any ISAR following vaccination than in those without an ISAR. Local pain, induration, swelling and systemic fever were significantly correlated with higher GMCs for IgG anti-HPV-16 and/or anti-HPV-18, respectively. Furthermore, the analyses of the immunogenicity bridging study of Cecolin® and the phase III trial of a hepatitis E vaccine yielded similar results. Based on these results, we built a scoring model to quantify the inflammation reactions and found that the high score of ISAR indicates the strong vaccine-induced antibody level. In conclusion, this study suggests inflammation-related adverse reactions following vaccination potentially indicate a stronger immune response.


Subject(s)
Hepatitis E/immunology , Human papillomavirus 16/immunology , Human papillomavirus 18/immunology , Papillomavirus Infections/immunology , Papillomavirus Vaccines/immunology , Vaccines, Synthetic/immunology , Viral Hepatitis Vaccines/immunology , Adolescent , Adult , Aged , Antibodies, Viral/immunology , Female , Hepatitis E/prevention & control , Hepatitis E/virology , Human papillomavirus 16/genetics , Human papillomavirus 18/genetics , Humans , Immunity , Immunoglobulin G/immunology , Male , Middle Aged , Papillomavirus Infections/prevention & control , Papillomavirus Infections/virology , Papillomavirus Vaccines/administration & dosage , Papillomavirus Vaccines/adverse effects , Papillomavirus Vaccines/genetics , Vaccination/adverse effects , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/adverse effects , Vaccines, Synthetic/genetics , Viral Hepatitis Vaccines/administration & dosage , Viral Hepatitis Vaccines/adverse effects , Viral Hepatitis Vaccines/genetics , Young Adult
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