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1.
BMJ Open ; 12(9): e059566, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-36100299

RESUMO

OBJECTIVES: In recent years, Iraq has expanded and revised the childhood immunisation schedule, but estimates of the costs of the programme are unavailable. The objective of this study was to estimate the economic costs of delivering childhood vaccines in Iraq from a government perspective. SETTING: Health facilities were sampled using multistage probabilistic sampling and stratifying the country into three regions: Central and South, North/Kurdistan Region, and Retaken Areas. Cost data were collected from 97 health facilities and 44 district and regional vaccine stores. Total national costs were extrapolated using sample weight calibration. PARTICIPANTS: Administrators at each health facility and vaccine store were interviewed using a standardised survey. PRIMARY AND SECONDARY OUTCOME MEASURES: Total costs of vaccine delivery per year, costs per dose delivered and delivery costs per fully vaccinated child. RESULTS: An estimated 15.3 million vaccine doses were delivered in 2018, costing US$99.35 million, excluding costs of vaccines and injection material. Nearly 90% of delivery costs were attributed to personnel salaries. Vaccine record-keeping and management (21%) and facility-based vaccine delivery (19%) were the largest cost contributors. Vaccine transport and storage, programme management, and outreach services represented 13%, 12% and 10%, respectively. All other activities represented less than 10% of the total cost. Average costs per dose delivered was US$6.48, ranging from US$9.13 in Retaken Areas to US$5.84 in the Central and South. Vaccine delivery costs per fully vaccinated child totalled US$149. CONCLUSION: This study provides baseline evidence of the current programme costs and human resource uses which can be used for annual planning, identifying areas for improvement, and targeting strategies to increase programme efficiency.


Assuntos
Programas de Imunização , Vacinas , Criança , Estudos Transversais , Instalações de Saúde , Humanos , Iraque
3.
BMJ Open ; 12(8): e058570, 2022 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-35953251

RESUMO

OBJECTIVES: Vaccine hesitancy remains a major barrier to immunisation coverage worldwide. We explored influence of hesitancy on coverage and factors contributing to vaccine uptake during a national measles-rubella (MR) campaign in Indonesia. DESIGN: Secondary analyses of qualitative and quantitative data sets from existing cross-sectional studies conducted during and around the campaign. METHODS: Quantitative data used in this assessment included daily coverage reports generated by health workers, district risk profiles that indicate precampaign immunisation programme performance, and reports of campaign cessation due to vaccine hesitancy. We used t-test and χ2 tests for associations. The qualitative assessment employed three parallel national and regional studies. Deductive thematic analysis examined factors for acceptance among caregivers, health providers and programme managers. RESULTS: Coverage data were reported from 6462 health facilities across 395 districts from 1 August to 31 December 2018. The average district coverage was 73%, with wide variation between districts (2%-100%). One-third of districts fell below 70% coverage thresholds. Sixty-two of 395 (16%) districts paused the campaign due to hesitancy. Coverage among districts that never paused campaign activities due to hesitancy was significantly higher than rates for districts ever-pausing the campaign (81% vs 42%; p<0.001). Precampaign adequacy of district immunisation programmes did not explain coverage gaps (p=0.210). Qualitative analysis identified acceptance enablers including using digital health monitoring and feedback systems, increasing caregiver knowledge and awareness, making immunisation social norm, effective cross-sectoral collaboration, conducive service environment and positive experiences for mothers and children. Barriers included misinformation diffusion on social media, halal-haram issues, lack of healthcare provider knowledge, negative family influences and traditions, previous poor experiences and misinformation on adverse events. CONCLUSION: Barriers to vaccine uptake contributed to coverage gaps during national MR campaign in Indonesia. A range of supply-related and demand-related strategies were identified to address hesitancy contributors. Advancing a portfolio of tailored multilevel interventions will be critical to enhance vaccine acceptance.


Assuntos
Sarampo , Rubéola (Sarampo Alemão) , Vacinas , Criança , Estudos Transversais , Humanos , Programas de Imunização/métodos , Indonésia , Sarampo/prevenção & controle , Rubéola (Sarampo Alemão)/prevenção & controle , Vacinação
4.
Vaccine ; 40(39): 5691-5700, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36030126

RESUMO

BACKGROUND: Vaccination is a cost-effective disease prevention measure. Sustainable financing is critical to successful implementation of vaccination programs. Countries in the Middle East and Africa (MEA) have vaccination programs that remain highly vulnerable to budget limitations. OBJECTIVES: The objectives of this study were to understand the current vaccine financing landscape in MEA; to assess the availability and variability of data on vaccination budgets, expenditure and schedules including introductions of new vaccines; and to identify and describe key trends. METHOD: A targeted literature review was conducted for 69 MEA countries for data between 2010 and 2019. Descriptive analysis of the collected data was conducted. RESULTS: Data on vaccination expenditure were available for 96% of the countries. However, data on vaccination budget were limited, and the variability was high. The median vaccination expenditure per capita was between US$0.57 and US$1.02. High-income countries spent the most on vaccination per capita (median US$3.41) compared to low-income countries (median US$0.69). The highest vaccination expenditure per capita was in countries that receive 100% government funding of vaccination programs (US$0.87) compared to those where government pays for > 0% to < 50% of vaccination expenditure (US$0.74). Vaccination expenditure as a proportion of gross domestic product was the highest (0.10%) in low-income countries and the lowest in high-income countries (0.01%). Vaccination expenditure as proportion of healthcare expenditure was the highest (1.76%) in low-income countries and the lowest in high-income countries (0.33%). Statistically significant trends in median expenditure per capita were identified for 27% of the countries. During this period, an average of 4.4 vaccines were introduced. CONCLUSION: Data on vaccination expenditure in MEA was available for detailed analysis, and it was useful to understand the characteristics of vaccination funding in the region. It is important to secure adequate financing to sustain current vaccination programs and to introduce new vaccines.


Assuntos
Países em Desenvolvimento , Vacinas , África , Financiamento Governamental , Programas de Imunização , Vacinação
5.
JAMA Netw Open ; 5(8): e2227680, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35984657

RESUMO

Importance: COVID-19 booster vaccine can strengthen waning immunity and widen the range of immunity against new variants. Objective: To describe geographic, occupational, and sociodemographic variations in uptake of COVID-19 booster doses among fully vaccinated US adults. Design, Setting, and Participants: This cross-sectional survey study used data from the Household Pulse Survey conducted from December 1, 2021, to January 10, 2022. Household Pulse Survey is an online, probability-based survey conducted by the US Census Bureau and is designed to yield estimates nationally, by state, and across selected metropolitan areas. Main Outcomes and Measures: Receipt of a booster dose was defined as taking 2 or more doses of COVID-19 vaccines with the first one being the Johnson and Johnson (Janssen) vaccine, or taking 3 or more doses of any of the other COVID-19 vaccines. Weighted prevalence estimates (percentages) were computed overall and among subgroups. Adjusted prevalence ratios (APRs) were calculated in a multivariable Poisson regression model to explore correlates of receiving a booster dose among those fully vaccinated. Results: A total of 135 821 adults completed the survey. Overall, 51.0% were female and 41.5% were aged 18 to 44 years (mean [SD] age, 48.07 [17.18] years). Of fully vaccinated adults, the percentage who reported being boosted was 48.5% (state-specific range, from 39.1% in Mississippi to 66.5% in Vermont). Nationally, the proportion of boosted adults was highest among non-Hispanic Asian individuals (54.1%); those aged 65 years or older (71.4%); those with a doctoral, professional, or master's degree (68.1%); those who were married with no children in the household (61.2%); those with annual household income of $200 000 or higher (69.3%); those enrolled in Medicare (70.9%); and those working in hospitals (60.5%) or in deathcare facilities (eg, funeral homes; 60.5%). Conversely, only one-third of those who ever received a diagnosis of COVID-19, were enrolled in Medicaid, working in pharmacies, with less than a high school education, and aged 18 to 24 years old were boosted. Multivariable analysis of pooled national data revealed that compared with those who did not work outside their home, the likelihood of being boosted was higher among adults working in hospitals (APR, 1.23; 95% CI, 1.17-1.30), ambulatory health care centers (APR, 1.16; 95% CI, 1.09-1.24), and social service settings (APR, 1.08; 95% CI, 1.01-1.15), whereas lower likelihood was seen among those working in food or beverage stores (APR, 0.85; 95% CI, 0.74-0.96) and the agriculture, forestry, fishing, or hunting industries (APR, 0.83; 95% CI, 0.72-0.97). Conclusions and Relevance: These findings suggest continuing disparities in receipt of booster vaccine doses among US adults. Targeted efforts at populations with low uptake may be needed to improve booster vaccine coverage in the US.


Assuntos
COVID-19 , Vacinas , Adolescente , Adulto , Idoso , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Estudos Transversais , Feminino , Humanos , Masculino , Medicare , Pessoa de Meia-Idade , Estados Unidos/epidemiologia , Adulto Jovem
6.
Front Public Health ; 10: 944887, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35958854

RESUMO

Background: Vaccine hesitancy in the face of the COVID-19 pandemic is a complex issue that undermines our national ability to reduce the burden of the disease and control the pandemic. The COVID-19 pandemic revealed widening health disparities and disproportionate adverse health outcomes in terms of transmission, hospitalizations, morbidity and mortality among Arizona's Latinx rural, underserved, farmworker, disabled and elderly populations. In March 2021, ~8.1% of those vaccinated were Latinx, though Latinxs make up 32% of Arizona's population. The Arizona Vaccine Confidence Network (AzVCN) proposed to leverage the expertise of the Arizona Prevention Research Center (AzPRC) and the resources of the Mel and Enid Zuckerman College of Public Health (MEZCOPH) Mobile Health Unit (MHU) to identify, implement and evaluate a MHU intervention to increase uptake of COVID-19 vaccines. Methods: The AzVCN focused efforts on Latinx, rural, un/underinsured and farmworker communities in the four Arizona border counties that are at greater risk of COVID-19 morbidity and mortality and may have limited access to vaccination and other essential health services. The AzVCN used listening sessions to create a feedback loop with key stakeholders and critical health care workers to validate barriers/enablers and identify solutions to increase vaccination uptake emerging from the network. The AzVCN also implemented a community-based intervention using community health workers (CHWs) based in a MHU to increase knowledge of the COVID-19 vaccines, reduce vaccination hesitancy and increase vaccination uptake among Latinx rural, un/underinsured and farmworker populations in Southern Arizona. Results: AzVCN outcomes include: identification of enablers and barriers of COVID-19 vaccination in the priority populations; identification of strategies and solutions to address vaccine hesitancy and increase vaccine uptake among priority population; and evidence that the proposed solutions being tested through the AzVCN contribute to increased vaccine uptake among the priority populations. Conclusion: Through these efforts the AzPRC contributed to the CDC's Vaccinate with Confidence Strategy by collaborating with CHWs and other key stakeholders to engage directly with communities in identifying and addressing structural and misinformation barriers to vaccine uptake.


Assuntos
COVID-19 , Equidade em Saúde , Vacinas , Idoso , Arizona , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Agentes Comunitários de Saúde , Humanos , Pandemias
7.
J Prev Med Hyg ; 63(2): E257-E269, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35968072

RESUMO

Introduction: The distrust, delay and refusal of vaccinations represent serious threats to global public health. As demonstrated by the dramatic worldwide impact of the COVID-19 pandemic, adequate vaccine coverage against infectious diseases is essential towards the preservation and function of virtually every aspect of our society. While the determinants of vaccine hesitancy and pandemic concern have been widely investigated, conflicting evidence exists with regards to their association with education levels and political views. Methods: This study aimed to investigate whether science literacy levels and standpoint on social and economic matters are associated with different levels of vaccine confidence and COVID-19 concern. An online survey was circulated amongst participants recruited via convenience sampling, and data were analysed using non-parametric statistical tests. Results: The survey (n = 389) highlighted that participants who studied Science at General Certificate of Secondary Education level have a lower vaccine confidence than those with both lower and higher levels of science education. Participants with neutral/centrist political views expressed lower confidence than those with a libertarian social stance or a left-wing economic stance. A higher concern with the COVID-19 pandemic was associated with lower levels of science education, libertarian social views, and left-wing economic views. Conclusions: The present study provides novel insight on the educational and political factors associated with vaccine hesitancy and pandemic concern within a British population sample.


Assuntos
COVID-19 , Vacinas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Humanos , Alfabetização , Pandemias/prevenção & controle , Vacinação
8.
Vet Immunol Immunopathol ; 251: 110460, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35901545

RESUMO

Low-cost adjuvants are urgently needed for the development of veterinary vaccines able to trigger strong immune responses. In this work, we describe a method to obtain a low-cost cage-like particles (ISCOMATRIX-like) adjuvant useful to formulate veterinary vaccines candidates. The main components to form the particles are lipids and saponins, which were obtained from egg yolk by ethanolic extraction and by dialyzing a non-refined saponins extract, respectively. Lipids were fully characterized by thin layer chromatography (TLC) and gas-chromatography (GC) and enzymatic methods, and saponins were characterized by TLC, HPLC and MALDI-TOF. Cage-like particles were prepared with these components or with commercial inputs. Both particles and the traditional Alum used in veterinary vaccines were compared by immunizing mice with Ovalbumin (OVA) formulated with these adjuvants and assessing IgG1, IgG2a anti OVA antibodies and specific Delayed-type Hypersensitivity (DTH). In the yolk extract, a mixture of phospholipids, cholesterol and minor components of the extract (e.g. lyso-phospholipids) with suitable proportions to generate cage-like particles was obtained. Also, semi-purified saponins with similar features to those of the QuilA® were obtained. Cage-like particles prepared with these components have 40-50 nm and triggers similar levels of Anti-OVA IgG1 and DTH than with commercial inputs but higher specific-IgG2a. Both adjuvants largely increased the levels of IgG1, IgG2a and DTH in relation to the formulation with Alum. The methods described to extract lipids from egg yolk and saponins from non-refined extract allowed us to obtain an inexpensive and highly effective adjuvant.


Assuntos
Saponinas , Vacinas , Adjuvantes Imunológicos/química , Animais , Imunoglobulina G , Camundongos , Ovalbumina
9.
J Law Med Ethics ; 50(S1): 29-31, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35902083

RESUMO

The complexity and inefficiency of the U.S. health care system complicates the distribution of life-saving medical technologies. When the public health is at stake, however, there are alternatives. The proposal for a national PrEP program published in this issue of the Journal applies some of the lessons of the national COVID vaccine campaign to HIV prevention. In doing so, it draws on other examples of public health approaches to the financing of medical technology, from vaccines for children to hepatitis C treatment.


Assuntos
COVID-19 , Infecções por HIV , Vacinas , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Criança , Infecções por HIV/prevenção & controle , Humanos , Preparações Farmacêuticas
10.
Front Public Health ; 10: 917242, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35844884

RESUMO

COVID-19 vaccines have been developed and administered at record pace in order to curtail the impact of the COVID-19 pandemic. Vaccine hesitancy has impacted uptake unequally across different groups. This study explores the drivers for vaccine hesitancy in ethnic minority groups in the UK, the impact of social media on vaccine hesitancy and how vaccine hesitancy may be overcome. Twelve semi-structured interviews were conducted, coded and thematically analyzed with participants from ethnic minority groups in the UK who identified as vaccine hesitant. Social media played a significant role in vaccine hesitancy. For those who considered themselves healthy, seeing misinformation of extreme side effects relating to COVID-19 vaccinations on social media resulted in the opinion that the risk of vaccination is greater than risk from COVID-19 infection. For women, misinformation on social media regarding fertility was a reason for delaying or not getting vaccinated. Participants who had sources of information they trusted in outside of social media were more likely to choose to get vaccinated. This study identified the broad spectrum of views on vaccine hesitancy in ethnic minority groups in the UK. Enabling factors such as a desire to travel, and positive public health messaging can increase vaccine uptake, whereas a lack of trusted sources of information may cause vaccine hesitancy. Further research is required to combat misinformation and conspiracy theories. Effective methods include actively responding and disproving the misinformation. For an inclusive vaccination programme that reduces health inequality, policy makers should build trust amongst marginalized communities and address their concerns through tailored public health messaging.


Assuntos
COVID-19 , Vacinas , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Minorias Étnicas e Raciais , Etnicidade , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Disparidades nos Níveis de Saúde , Humanos , Grupos Minoritários , Pandemias , Aceitação pelo Paciente de Cuidados de Saúde , Reino Unido , Hesitação Vacinal
11.
Nat Commun ; 13(1): 3942, 2022 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-35803909

RESUMO

In the COVID-19 pandemic many countries required COVID certificates, proving vaccination, recovery, or a recent negative test, to access public and private venues. We estimate their effect on vaccine uptake for France, Germany, and Italy using counterfactuals constructed via innovation diffusion theory. The announcement of COVID certificates during summer 2021 were associated - although causality cannot be directly inferred - with increased vaccine uptake in France of 13.0 (95% CI 9.7-14.9) percentage points (p.p.) of the total population until the end of the year, in Germany 6.2 (2.6-6.9) p.p., and in Italy 9.7 (5.4-12.3) p.p. Based on these estimates, an additional 3979 (3453-4298) deaths in France, 1133 (-312-1358) in Germany, and 1331 (502-1794) in Italy were averted; and gross domestic product (GDP) losses of €6.0 (5.9-6.1) billion in France, €1.4 (1.3-1.5) billion in Germany, and €2.1 (2.0-2.2) billion in Italy were prevented. Notably, in France, the application of COVID certificates averted high intensive care unit occupancy levels where prior lockdowns were instated.


Assuntos
COVID-19 , Vacinas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Controle de Doenças Transmissíveis , França/epidemiologia , Alemanha/epidemiologia , Humanos , Itália/epidemiologia , Avaliação de Resultados em Cuidados de Saúde , Pandemias/prevenção & controle
14.
Epidemics ; 40: 100605, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35810698

RESUMO

The response to the COVID-19 pandemic in the U.S prompted abrupt and dramatic changes to social contact patterns. Monitoring changing social behavior is essential to provide reliable input data for mechanistic models of infectious disease, which have been increasingly used to support public health policy to mitigate the impacts of the pandemic. While some studies have reported on changing contact patterns throughout the pandemic, few have reported differences in contact patterns among key demographic groups and none have reported nationally representative estimates. We conducted a national probability survey of US households and collected information on social contact patterns during two time periods: August-December 2020 (before widespread vaccine availability) and March-April 2021 (during national vaccine rollout). Overall, contact rates in Spring 2021 were similar to those in Fall 2020, with most contacts reported at work. Persons identifying as non-White, non-Black, non-Asian, and non-Hispanic reported high numbers of contacts relative to other racial and ethnic groups. Contact rates were highest in those reporting occupations in retail, hospitality and food service, and transportation. Those testing positive for SARS-CoV-2 antibodies reported a higher number of daily contacts than those who were seronegative. Our findings provide evidence for differences in social behavior among demographic groups, highlighting the profound disparities that have become the hallmark of the COVID-19 pandemic.


Assuntos
COVID-19 , Vacinas , Adulto , COVID-19/epidemiologia , Humanos , Pandemias , Grupos Raciais , SARS-CoV-2
15.
Yale J Biol Med ; 95(2): 265-269, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35782470

RESUMO

This perspectives piece focuses on the detrimental cost of ignoring vaccines and refusing vaccination against COVID-19 in the United States. Much of the existing literature regarding the consequences of the unvaccinated emphasizes the impact to population health; however, few academic articles have explored the burden the unvaccinated pose to various sectors of society. This paper analyzes the impact that the unvaccinated have on healthcare systems, the US economy, and global health. Throughout the COVID-19 pandemic, unvaccinated populations were found to have put significant strain on healthcare systems, depleting medical resources and contributing to high rates of healthcare worker shortages. Furthermore, research suggests that between November and December 2021, over 692,000 preventable hospitalizations occurred in unvaccinated individuals, costing the US economy over $13.8 billion. Lastly, it is proposed that the strong international presence of the US, when coupled with high levels of disease transmissibility in the unvaccinated, provides a significant threat to global health. In conclusion, the unvaccinated have caused impacts far beyond that of population health; they have also posed a burden to healthcare systems, the economy, and global public health.


Assuntos
COVID-19 , Vacinas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Saúde Global , Humanos , Pandemias/prevenção & controle , Estados Unidos/epidemiologia , Vacinação
16.
Yale J Biol Med ; 95(2): 271-280, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35782474

RESUMO

This paper presents an ethical argument in support of an international Pandemic Treaty. It argues that an international Pandemic Treaty is the best way to mark progress on global vaccine equity and broader issues of global pandemic preparedness and response which came to light during the coronavirus disease 2019 (COVID-19) pandemic. Section I evaluates principles of multilateral charity, national security, and international diplomacy standardly invoked in debates about global vaccine allocation and argues that these approaches fall short. Section II explicates notions of solidarity, duties to the least well-off, and mutual aid as ethical values more fitting for an era of emerging infectious diseases. Section III relates the discussion to an international Pandemic Treaty and presents legal, pragmatic, and ethical reasons to support it. The paper concludes that in an interconnected world, fair sharing of vaccines between nations is morally mandatory.


Assuntos
COVID-19 , Doenças Transmissíveis Emergentes , Vacinas , COVID-19/prevenção & controle , Humanos , Cooperação Internacional , Pandemias/prevenção & controle
17.
Yale J Biol Med ; 95(2): 257-263, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35782479

RESUMO

While vaccine hesitancy is well documented in the literature among the Latinx community, little attention or effort is given to the nuances among the members of individual communities, such as country of origin, immigration status, generational status, primary language, race, age, sex, gender, or rural residence and how these complexities affect vaccine messaging and uptake. We have evidence that this heterogeneity causes differences in access to healthcare, attitudes towards vaccines, and degree of health disparities. In this review we will describe their impact on vaccination rates in the Latinx community, highlighting missed opportunities for public health outreach, and how targeted messaging could improve vaccine uptake.


Assuntos
Vacinação , Vacinas , Humanos
18.
Arch Microbiol ; 204(8): 479, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35831726

RESUMO

In this study, calcium phosphate nanoparticles-based (STCNV) and montanide oil adjuvant vaccine (STOAV) containing outer membrane proteins (Omps) of S. Typhi were evaluated for inducing oxidative stress indicators [reduced glutathione (GSH), lipid peroxidation (LPO), catalase, superoxide dismutase (SOD), and total protein] in the tissues of mice after vaccination. The GSH levels though slightly high in the liver, kidney, and lungs of STCNV group were not significantly different from STOAV and the control group (STC). There was no significant difference in LPO levels in any group for any tissue. The significantly lower activities of catalase were observed in the kidney and lungs of the STCNV group as compared to STOAV and STC group, while in the liver, STCNV group revealed lower catalase activity in comparison to the control group. No significant difference in the SOD activities between the two vaccinated groups was observed. The total protein contents in all the organs showed no significant difference in the vaccinated and the control group. The vaccines may induce long-term inflammatory response and consequently damage vital organs; this study revealed no long-term oxidative stress in all the three vital organs, suggesting that these vaccines may not cause oxidative damages in the vital organs of mice.


Assuntos
Nanopartículas , Vacinas , Adjuvantes Imunológicos , Animais , Antioxidantes/farmacologia , Catalase/metabolismo , Glutationa/metabolismo , Proteínas de Membrana/metabolismo , Camundongos , Óleo Mineral , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Salmonella typhi/metabolismo , Superóxido Dismutase/metabolismo
19.
BMJ Open ; 12(7): e057281, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35831042

RESUMO

OBJECTIVE: By using health code blockchain, cities can maximise the use of personal information while maximising the protection of personal privacy in the monitoring and evaluation of the effectiveness of listed vaccines. DESIGN: This study constructs an urban COVID-19 listed vaccine effectiveness (VE) monitoring, evaluation and application system based on the health code blockchain. This study uses this system and statistical simulation to analyse three urban application scenarios, namely evaluating the vaccination rate (VR) and determining the optimal vaccination strategy, evaluating herd immunity and monitoring the VE on variant. MAIN OUTCOME MEASURES: The primary outcomes first establish an urban COVID-19 listed VE monitoring, evaluation and application system by using the health code blockchain, combined with the dynamic monitoring model of VE, the evaluation index system of VE and the monitoring and evaluation system of personal privacy information use, and then three measures are analysed in urban simulation: one is to take the index reflecting urban population mobility as the weight to calculate the comprehensive VR, the second is to calculate the comprehensive basic reproduction number (R) in the presence of asymptomatic persons, the third is to compare the difference between the observed effectiveness and the true effectiveness of listed vaccines under virus variation. RESULTS: Combining this system and simulation, this study finds: (1) The comprehensive VR, which is weighted to reflect urban population mobility, is more accurate than the simple VR which does not take into account urban population mobility. Based on population mobility, the algorithm principle of urban optimal vaccination strategy is given. In the simulation of urban listed vaccination involving six regions, programmes 1 and 5 have the best protective effect among the eight vaccination programmes, and the optimal vaccination order is 3-5-2-4-6-1. (2) In the presence of asymptomatic conditions, the basic reproduction number, namely R0*(1-VR*VE), does not accurately reflect the effect of herd immunity, but the comprehensive basic reproduction number (R) should be used. The R is directly proportional to the proportion of asymptomatic people (aw) and the duration of the incubation period (ip), and inversely proportional to the VR, the VE and the number of days transmitted in the ip (k). In the simulation analysis, when symptomatic R0=3, even with aw=0.2, the R decreases to nearly 1 until the VR reaches 95%. When aw=0.8, even when the entire population is vaccinated, namely VR=1, the R is 1.688, and still significantly greater than 1. If the R is to be reduced to 1, the VE needs to be increased to 0.87. (3) This system can more comprehensively and accurately grasp the impact of the variant virus on urban VE. The traditional epidemiological investigation can lose the contacts of infected persons, which leads to the deviation between the observed effectiveness and the true effectiveness. Virus variation aggravates the loss, and then increases the deviation. Simulation case 1 assumes the unvaccinated rate of 0.8, the ongoing VR of 0.1, the completed VR of 0.1 and an average infection rate of 2% for the variant virus. If a vaccine is more than 90% effectiveness against the premutant virus, but only 80% effectiveness against the mutant virus, and because 80% of the unvaccinated people who are not infected are not observed, the observed effectiveness of the vaccine is 91.76%, it will lead to the wrong judgement that the VE against the variant virus is not decreased. Simulation case 2 assumes the unvaccinated rate of 0.8, the ongoing VR of 0.1, the completed VR of 0.1 and an average infection rate of 5% for the variant virus. Simulation finds that the higher the proportion of unvaccinated infected people who are not observed, the lower the estimate of observed effectiveness; and the lower the true effectiveness, the larger the gap between observed effectiveness and true effectiveness. Simulation case 3 assumes the unvaccinated rate of 0.2, the ongoing VR of 0.2, the completed VR of 0.6 and an average infection rate of 2% for the variant virus. Simulation finds that the higher the proportion of unobserved completed vaccination patients who are not infected, the lower the estimate of observed effectiveness; and the lower the true effectiveness, the larger the gap between observed effectiveness and true effectiveness. Simulation case 4 assumes the unvaccinated rate of 0.2, the ongoing VR of 0.2, the completed VR of 0.6 and an average infection rate of 5% for the variant virus. If a vaccine is more than 90% effectiveness against the premutant virus, but only 80% effectiveness against the mutant virus, and because 80% of the infected people with complete vaccination are not observed, the observed effectiveness of the vaccine is 91.95%, similar to case 1, it will lead to the wrong judgement that the VE against the variant virus is not decreased. CONCLUSION: Compared with traditional epidemiological investigation, this system can meet the challenges of accelerating virus variation and a large number of asymptomatic people, dynamically monitor and accurately evaluate the effectiveness of listed vaccines and maximise personal privacy without locking down the relevant area or city. This system established in this study could serve as a universal template for monitoring and evaluating the effectiveness of COVID-19 listed vaccines in cities around the world. If this system can be promoted globally, it will promote countries to strengthen unity and cooperation and enhance the global ability to respond to COVID-19.


Assuntos
Blockchain , COVID-19 , Vacinas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Vacinação
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