Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
1.
Sci Rep ; 11(1): 21844, 2021 11 04.
Article in English | MEDLINE | ID: covidwho-1503889

ABSTRACT

This study assesses attitudes towards COVID-19 vaccination and the predictive value of COVID-VAC, a novel scale, among adults in the four largest US metropolitan areas and nationally. A 36-item survey of 6037 Americans was conducted in mid-April 2021. The study reports factors for COVID-19 vaccine acceptance among: (1) already vaccinated; (2) unvaccinated but willing to accept a vaccine; and (3) unvaccinated and unwilling to vaccinate. More than 20% were unwilling to vaccinate, expressing concerns about vaccine efficacy and safety and questioning the disease's severity. Poverty, working outside of the home and conservative political views are predictors of unwillingness. Conversely, those who either personally tested positive for COVID-19, or had a family member who did so, were more likely to accept vaccination. Majorities of all respondents supported vaccination mandates for employees and university students. Respondents preferred to receive vaccines in their doctor´s office. Lower income and conservative ideology, but not race, were strongly associated with vaccine unwillingness. The predictive value of COVID-VAC was demonstrated. While vaccination mandates are likely to be accepted, additional effective, targeted interventions to increase vaccine uptake are needed urgently.


Subject(s)
COVID-19/psychology , Vaccination Refusal/psychology , Vaccination Refusal/trends , Adult , Attitude , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/supply & distribution , Female , Guideline Adherence/trends , Health Policy/trends , Humans , Intention , Male , Middle Aged , SARS-CoV-2/pathogenicity , Surveys and Questionnaires , United States , Vaccination/psychology , Vaccination/trends , Vaccines/pharmacology
2.
PLoS One ; 16(10): e0259059, 2021.
Article in English | MEDLINE | ID: covidwho-1496525

ABSTRACT

As safe and effective vaccines become widely available, attaining herd immunity and limiting the spread of COVID-19 will depend on individuals choosing to vaccinate-and doing so quickly enough to outpace mutations. Using online surveys conducted across six Latin American countries in January 2021, we experimentally assess messages designed to counteract informational deficiencies and collective action problems that may drive hesitancy. We first find that basic vaccine information persuades around 8% of hesitant individuals to become willing to vaccinate, reduces intended wait to vaccinate by 0.4 months, and increases willingness to encourage others to vaccinate. Rather than facilitating free riding, learning, or social conformity, additional information about others' behavior increases vaccine acceptance when respondents expect herd immunity will be achieved. Finally, priming the social approval benefits of vaccinating also increases vaccine acceptance. These results suggest that providing information and shaping social expectations and incentives could both significantly increase vaccine uptake.


Subject(s)
COVID-19/psychology , Vaccination Refusal/psychology , Vaccination/psychology , COVID-19/prevention & control , COVID-19 Vaccines/therapeutic use , Health Knowledge, Attitudes, Practice , Humans , Latin America , Patient Acceptance of Health Care/psychology , Patient Acceptance of Health Care/statistics & numerical data , Persuasive Communication , SARS-CoV-2/pathogenicity , Surveys and Questionnaires , Vaccination/statistics & numerical data , Vaccination Refusal/trends , Vaccines/pharmacology
3.
Viruses ; 13(10)2021 09 24.
Article in English | MEDLINE | ID: covidwho-1438745

ABSTRACT

SARS-CoV-2 vaccine clinical trials assess efficacy against disease (VEDIS), the ability to block symptomatic COVID-19. They only partially discriminate whether VEDIS is mediated by preventing infection completely, which is defined as detection of virus in the airways (VESUSC), or by preventing symptoms despite infection (VESYMP). Vaccine efficacy against transmissibility given infection (VEINF), the decrease in secondary transmissions from infected vaccine recipients, is also not measured. Using mathematical modeling of data from King County Washington, we demonstrate that if the Moderna (mRNA-1273QS) and Pfizer-BioNTech (BNT162b2) vaccines, which demonstrated VEDIS > 90% in clinical trials, mediate VEDIS by VESUSC, then a limited fourth epidemic wave of infections with the highly infectious B.1.1.7 variant would have been predicted in spring 2021 assuming rapid vaccine roll out. If high VEDIS is explained by VESYMP, then high VEINF would have also been necessary to limit the extent of this fourth wave. Vaccines which completely protect against infection or secondary transmission also substantially lower the number of people who must be vaccinated before the herd immunity threshold is reached. The limited extent of the fourth wave suggests that the vaccines have either high VESUSC or both high VESYMP and high VEINF against B.1.1.7. Finally, using a separate intra-host mathematical model of viral kinetics, we demonstrate that a 0.6 log vaccine-mediated reduction in average peak viral load might be sufficient to achieve 50% VEINF, which suggests that human challenge studies with a relatively low number of infected participants could be employed to estimate all three vaccine efficacy metrics.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , COVID-19/immunology , COVID-19 Vaccines/pharmacology , Humans , Models, Theoretical , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Vaccines/pharmacology , Washington
4.
Pediatr Ann ; 49(12): e509-e515, 2020 Dec 01.
Article in English | MEDLINE | ID: covidwho-1375499

ABSTRACT

Vaccines are one of the greatest public health achievements, protecting children and adults against numerous infectious diseases; however, the complex, rigorous process of vaccine development is unknown to many. A candidate vaccine undergoes extensive evaluation of safety and efficacy to meet licensure requirements before recommendations for use become policy. This time-consuming process involves an intricate collaboration among academia, public and private organizations, and federal agencies to ensure that safety is prioritized in every step. Vaccine safety continues to be monitored after licensure through a robust system. Yet, vaccine hesitancy remains a major challenge, especially now with the coronavirus disease 2019 (COVID-19) pandemic and concerns about the speed with which candidate vaccines are being developed. This article reviews the vaccine development process and the systems in place to ensure safety and effectiveness. A better understanding of these topics is necessary to address concerns and improve public acceptance of all vaccines, particularly COVID-19 vaccines. [Pediatr Ann. 2020;49(12):e509-e515.].


Subject(s)
Drug Approval , Vaccines/pharmacology , Clinical Trials as Topic , Humans , Licensure , Product Surveillance, Postmarketing , Safety Management , United States , United States Food and Drug Administration
5.
PLoS One ; 16(8): e0254605, 2021.
Article in English | MEDLINE | ID: covidwho-1367703

ABSTRACT

The re-emergence of virulent strains of the Infectious Bursal Disease Virus (IBDV) leads to significant economic losses of poultry industry in Pakistan during last few years. This disease causes the infection of bursa, which leads to major immune losses. A total number of 30 samples from five IBD outbreaks during the period of 2019-20 were collected from different areas of Faisalabad district, Pakistan and assayed by targeting the IBD virus VP2 region through RT-PCR. Among all the outbreaks, almost 80% of poultry birds were found positive for the IBDV. The bursa tissues were collected from the infected birds and histopathological examination of samples revealed severe lymphocytic depletion, infiltration of inflammatory cells, and necrosis of the bursa of Fabricius (BF). Positive samples were subjected to re-isolation and molecular characterization of IBDV. The Pakistan IBDV genes were subjected to DNA sequencing to determine the virus nucleotide sequences. The sequences of 100 Serotype-I IBDVs showing nearest homology were compared and identified with the study sequence. The construction of the phylogenetic tree for nucleotide sequences was accomplished by the neighbor-joining method in MEGA-6 with reference strains. The VP2 segment reassortment of IBDVs carrying segment A were identified as one important type of circulating strains in Pakistan. The findings indicated the molecular features of the Pakistan IBDV strains playing a role in the evolution of new strains of the virus, which will contribute to the vaccine selection and effective prevention of the disease.


Subject(s)
Birnaviridae Infections/epidemiology , Infectious bursal disease virus/pathogenicity , Poultry/virology , Vaccines/pharmacology , Animals , Birnaviridae Infections/veterinary , Birnaviridae Infections/virology , Bursa of Fabricius/pathology , Bursa of Fabricius/virology , Chickens/virology , Disease Outbreaks/veterinary , Humans , Infectious bursal disease virus/genetics , Pakistan/epidemiology , Phylogeny , Poultry Diseases/virology , Viral Structural Proteins/genetics , Viral Structural Proteins/immunology
6.
Sci Rep ; 11(1): 15431, 2021 07 29.
Article in English | MEDLINE | ID: covidwho-1332853

ABSTRACT

Currently, no approved vaccine is available against the Middle East respiratory syndrome coronavirus (MERS-CoV), which causes severe respiratory disease. The spike glycoprotein is typically considered a suitable target for MERS-CoV vaccine candidates. A computational strategy can be used to design an antigenic vaccine against a pathogen. Therefore, we used immunoinformatics and computational approaches to design a multi-epitope vaccine that targets the spike glycoprotein of MERS-CoV. After using numerous immunoinformatics tools and applying several immune filters, a poly-epitope vaccine was constructed comprising cytotoxic T-cell lymphocyte (CTL)-, helper T-cell lymphocyte (HTL)-, and interferon-gamma (IFN-γ)-inducing epitopes. In addition, various physicochemical, allergenic, and antigenic profiles were evaluated to confirm the immunogenicity and safety of the vaccine. Molecular interactions, binding affinities, and the thermodynamic stability of the vaccine were examined through molecular docking and dynamic simulation approaches, during which we identified a stable and strong interaction with Toll-like receptors (TLRs). In silico immune simulations were performed to assess the immune-response triggering capabilities of the vaccine. This computational analysis suggested that the proposed vaccine candidate would be structurally stable and capable of generating an effective immune response to combat viral infections; however, experimental evaluations remain necessary to verify the exact safety and immunogenicity profile of this vaccine.


Subject(s)
Epitopes/immunology , Middle East Respiratory Syndrome Coronavirus/immunology , Vaccines/immunology , Computational Biology , Coronavirus Infections/immunology , Coronavirus Infections/prevention & control , Epitopes, B-Lymphocyte/genetics , Epitopes, B-Lymphocyte/immunology , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , Humans , Immunogenicity, Vaccine/immunology , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Models, Molecular , Molecular Docking Simulation , Phylogeny , Protein Binding , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Helper-Inducer/immunology , Vaccines/pharmacology , Vaccines, DNA , Vaccines, Subunit/immunology , Viral Vaccines/immunology
7.
PLoS One ; 16(4): e0250797, 2021.
Article in English | MEDLINE | ID: covidwho-1206204

ABSTRACT

BACKGROUND: The accelerated vaccine development in response to the COVID-19 pandemic should lead to a vaccine being available early 2021, albeit in limited supply and possibly without full vaccine acceptance. We assessed the short-term impact of a COVID-19 immunization program with varying constraints on population health and non-pharmaceutical interventions (NPIs) needs. METHODS: A SARS-CoV-2 transmission model was calibrated to French epidemiological data. We defined several vaccine implementation scenarios starting in January 2021 based on timing of discontinuation of NPIs, supply and uptake constraints, and their relaxation. We assessed the number of COVID-19 hospitalizations averted, the need for and number of days with NPIs in place over the 2021-2022 period. RESULTS: An immunisation program under constraints could reduce the burden of COVID-19 hospitalizations by 9-40% if the vaccine prevents against infections. Relaxation of constraints not only reduces further COVID-19 hospitalizations (30-39% incremental reduction), it also allows for NPIs to be discontinued post-2021 (0 days with NPIs in 2022 versus 11 to 125 days for vaccination programs under constraints and 327 in the absence of vaccination). CONCLUSION: For 2021, COVID-19 control is expected to rely on a combination of NPIs and the outcome of early immunisation programs. The ability to overcome supply and uptake constraints will help prevent the need for further NPIs post-2021. As the programs expand, efficiency assessments will be needed to ensure optimisation of control policies post-emergency use.


Subject(s)
COVID-19 Vaccines/pharmacology , COVID-19/immunology , Vaccination/trends , France/epidemiology , Humans , Immunization Programs , Models, Theoretical , Pandemics/prevention & control , SARS-CoV-2/pathogenicity , Vaccines/pharmacology
SELECTION OF CITATIONS
SEARCH DETAIL