scholarly journals Adapting French COVID-19 vaccination campaign duration to variant dissemination

2021 ◽  
Author(s):  
Simon Pageaud ◽  
Nicolas Ponthus ◽  
Romain Gauchon ◽  
Catherine Pothier ◽  
Christophe Rigotti ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Vaccination Campaign ◽  
Virus Transmission ◽  
International Health ◽  
Vaccination Strategy ◽  
Health Crisis ◽  
Population Immunity ◽  
Best Response ◽  
Rapid Dissemination ◽  
Vaccination Campaigns

Background The outbreak of SARS-CoV-2 virus has caused a major international health crisis with serious consequences in terms of public health and economy. In France, two lockdown periods were decided in 2020 to avoid the saturation of intensive care units (ICU) and an increase in mortality. The rapid dissemination of variant SARS-CoV-2 VOC 202012/01 has strongly influenced the course of the epidemic. Vaccines have been rapidly developed. Their efficacy against the severe forms of the disease has been established, and their efficacy against disease transmission is under evaluation. The aim of this paper is to compare the efficacy of several vaccination strategies in the presence of variants in controlling the COVID-19 epidemic through population immunity. Methods An agent-based model was designed to simulate with different scenarios the evolution of COVID-19 pandemic in France over 2021 and 2022. The simulations were carried out ignoring the occurrence of variants then taking into account their diffusion over time. The expected effects of three Non-Pharmaceutical Interventions (Relaxed-NPI, Intensive-NPI, and Extended-NPI) to limit the epidemic extension were compared. The expected efficacy of vaccines were the values recently estimated in preventing severe forms of the disease (75% and 94%) for the current used vaccines in France (Pfizer-BioNTech and Moderna since January 11, 2021, and AstraZeneca since February 2, 2021). All vaccination campaigns reproduced an advanced age-based priority advised by the Haute Autoritć de Santć. Putative reductions of virus transmission were fixed at 0, 50, 75 and 90%. The effects of four vaccination campaign durations (6-month, 12-month, 18-month and 24-month) were compared. Results In the absence of vaccination, the presence of variants led to reject the Relaxed-NPI because of a high expected number of deaths (170 to 210 thousands) and the significant overload of ICUs from which 35 thousand patients would be deprived. In comparison with the situation without vaccination, the number of deaths was divided by 7 without ICU saturation with a 6-month vaccination campaign. A 12-month campaign would divide the number of deaths by 3 with Intensive-NPI and by 6 with Extended-NPI (the latter being necessary to avoid ICU saturation). With 18-month and 24-month vaccination campaigns without Extended-NPI, the number of deaths and ICU admissions would explode. Conclusion Among the four compared strategies the 6-month vaccination campaign seems to be the best response to changes in the dynamics of the epidemic due to the variants. The race against the COVID-19 epidemic is a race of vaccination strategy. Any further vaccination delay would increase the need of strengthened measures such as Extended-NPI to limit the number of deaths and avoid ICU saturation.

scholarly journals Expected Evolution of COVID-19 Epidemic in France for Several Combinations of Vaccination Strategies and Barrier Measures

Vaccines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1462
Author(s):  
Simon Pageaud ◽  
Catherine Pothier ◽  
Christophe Rigotti ◽  
Anne Eyraud-Loisel ◽  
Jean-Pierre Bertoglio ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
International Health ◽  
Vaccination Strategy ◽  
Economic Consequences ◽  
Health Crisis ◽  
Agent Based ◽  
Bed Days ◽  
Alpha Variant ◽  
Vaccination Campaigns ◽  
Related Mortality

The outbreak of the SARS-CoV-2 virus, enhanced by rapid spreads of variants, has caused a major international health crisis, with serious public health and economic consequences. An agent-based model was designed to simulate the evolution of the epidemic in France over 2021 and the first six months of 2022. The study compares the efficiencies of four theoretical vaccination campaigns (over 6, 9, 12, and 18 months), combined with various non-pharmaceutical interventions. In France, with the emergence of the Alpha variant, without vaccination and despite strict barrier measures, more than 600,000 deaths would be observed. An efficient vaccination campaign (i.e., total coverage of the French population) over six months would divide the death toll by 10. A vaccination campaign of 12, instead of 6, months would slightly increase the disease-related mortality (+6%) but require a 77% increase in ICU bed–days. A campaign over 18 months would increase the disease-related mortality by 17% and require a 244% increase in ICU bed–days. Thus, it seems mandatory to vaccinate the highest possible percentage of the population within 12, or better yet, 9 months. The race against the epidemic and virus variants is really a matter of vaccination strategy.

scholarly journals Estimating Parameters of Two-Level Individual-Level Models of the COVID-19 Epidemic Using Ensemble Learning Classifiers

2021 ◽  
Vol 8 ◽  
Author(s):  
Zeyi Liu ◽  
Rob Deardon ◽  
Yanghui Fu ◽  
Tahsin Ferdous ◽  
Tony Ware ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Ensemble Learning ◽  
Disease Transmission ◽  
Virus Transmission ◽  
Health Crisis ◽  
Individual Level ◽  
Learning Classifiers ◽  
Level Model ◽  
Computationally Expensive ◽  
Transmission Models

The ongoing COVID-19 pandemic has led to a serious health crisis, and information obtained from disease transmission models fitted to observed data is needed to inform containment strategies. As the transmission of virus varies from city to city in different countries, we use a two-level individual-level model to analyze the spatiotemporal SARS-CoV-2 spread. However, inference procedures such as Bayesian Markov chain Monte Carlo, which is commonly used to estimate parameters of ILMs, are computationally expensive. In this study, we use trained ensemble learning classifiers to estimate the parameters of two-level ILMs and show that the fitted ILMs can successfully capture the virus transmission among Wuhan and 16 other cities in Hubei province, China.

Vaccine hesitancy could derail COVID-19 control

2020 ◽  
Keyword(s):  
Large Scale ◽  
Vaccination Campaign ◽  
World Health ◽  
Vaccine Hesitancy ◽  
Content Type ◽  
Media Companies ◽  
Population Immunity ◽  
Great Hope ◽  
Health Organization ◽  
Vaccination Campaigns

Subject COVID-19 and vaccine hesitancy. Significance In 2019, the World Health Organization (WHO) cited “vaccine hesitancy” as one of the top ten threats to global health. Amid the COVID-19 pandemic, great hope has been placed on developing a vaccine to help countries return to normalcy. However, for a vaccine successfully to achieve the goal of population immunity, large-scale uptake is crucial. The growing anti-vaccination (‘anti-vax’) movement, which has strong pre-COVID-19 foundations, threatens to derail future vaccination campaigns. Impacts Stakeholders in public health will have to divert increasing amounts of resources to counter anti-vax content. Social media companies will come under increasing pressure to ensure they do not give a platform to misinformation relating to vaccinations. The full impact of the anti-vax movement will only be revealed when a vaccination campaign commences.

scholarly journals A spatial vaccination strategy to reduce the risk of vaccine-resistant variants

2021 ◽  
Author(s):  
Xiyun Zhang ◽  
Gabriela Lobinska ◽  
Michal Feldman ◽  
Eddie Dekel ◽  
Martin Nowak ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Herd Immunity ◽  
Vaccination Strategy ◽  
World Population ◽  
Global Risk ◽  
Resistant Variant ◽  
Infected People ◽  
Vaccination Rates ◽  
Population Immunity ◽  
Fitness Advantage

Abstract The process of vaccinating the world population against COVID-19 is expected to take well over a year to complete. As vaccination progresses and population immunity increases, a counteracting relaxation of social distancing measures is observed. The result will be a prolonged period of high disease prevalence combined with a fitness advantage for vaccine-resistant variants, implying a considerably increased probability that a resistant variant will spread in the population. In this paper we propose a spatial vaccination strategy that has the potential to dramatically reduce this risk. Instead of spreading the vaccination effort equally throughout a country, distinct geographic regions of the country are sequentially vaccinated, quickly bringing each to effective herd immunity. Regions with high vaccination rates will then have low infection rates and vice versa. Since people primarily interact with others in their own region, spatial vaccination will reduce the number of encounters between infected people (the source of mutations) and vaccinated people (who facilitate the spread of vaccine-resistant strains). Thus with proper logistic preparations, a spatial vaccination campaign could be highly effective in reducing the global risk of vaccine-resistant variants.

scholarly journals Dynamics of the COVID-19 epidemic in Ireland under mitigation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bernard Cazelles ◽  
Benjamin Nguyen-Van-Yen ◽  
Clara Champagne ◽  
Catherine Comiskey
Keyword(s):  
Transmission Rate ◽  
Vaccination Campaign ◽  
Virus Transmission ◽  
Reporting Rate ◽  
Mitigation Measures ◽  
Third Wave ◽  
The European Union ◽  
Hospital Data ◽  
Prevalence Survey ◽  
Epidemic Curve

Abstract Background In Ireland and across the European Union the COVID-19 epidemic waves, driven mainly by the emergence of new variants of the SARS-CoV-2 have continued their course, despite various interventions from governments. Public health interventions continue in their attempts to control the spread as they wait for the planned significant effect of vaccination. Methods To tackle this challenge and the observed non-stationary aspect of the epidemic we used a modified SEIR stochastic model with time-varying parameters, following Brownian process. This enabled us to reconstruct the temporal evolution of the transmission rate of COVID-19 with the non-specific hypothesis that it follows a basic stochastic process constrained by the available data. This model is coupled with Bayesian inference (particle Markov Chain Monte Carlo method) for parameter estimation and utilized mainly well-documented Irish hospital data. Results In Ireland, mitigation measures provided a 78–86% reduction in transmission during the first wave between March and May 2020. For the second wave in October 2020, our reduction estimation was around 20% while it was 70% for the third wave in January 2021. This third wave was partly due to the UK variant appearing in Ireland. In June 2020 we estimated that sero-prevalence was 2.0% (95% CI: 1.2–3.5%) in complete accordance with a sero-prevalence survey. By the end of April 2021, the sero-prevalence was greater than 17% due in part to the vaccination campaign. Finally we demonstrate that the available observed confirmed cases are not reliable for analysis owing to the fact that their reporting rate has as expected greatly evolved. Conclusion We provide the first estimations of the dynamics of the COVID-19 epidemic in Ireland and its key parameters. We also quantify the effects of mitigation measures on the virus transmission during and after mitigation for the three waves. Our results demonstrate that Ireland has significantly reduced transmission by employing mitigation measures, physical distancing and lockdown. This has to date avoided the saturation of healthcare infrastructures, flattened the epidemic curve and likely reduced mortality. However, as we await for a full roll out of a vaccination programme and as new variants potentially more transmissible and/or more infectious could continue to emerge and mitigation measures change silent transmission, challenges remain.

scholarly journals How does globalization affect COVID-19 responses?

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Steve J. Bickley ◽  
Ho Fai Chan ◽  
Ahmed Skali ◽  
David Stadelmann ◽  
Benno Torgler
Keyword(s):  
Infectious Disease ◽  
Disease Transmission ◽  
State Capacity ◽  
International Travel ◽  
Health Crisis ◽  
Government Effectiveness ◽  
Policy Responses ◽  
Travel Restrictions ◽  
High Government

Abstract Background The ongoing COVID-19 pandemic has highlighted the vast differences in approaches to the control and containment of coronavirus across the world and has demonstrated the varied success of such approaches in minimizing the transmission of coronavirus. While previous studies have demonstrated high predictive power of incorporating air travel data and governmental policy responses in global disease transmission modelling, factors influencing the decision to implement travel and border restriction policies have attracted relatively less attention. This paper examines the role of globalization on the pace of adoption of international travel-related non-pharmaceutical interventions (NPIs) during the coronavirus pandemic. This study aims to offer advice on how to improve the global planning, preparation, and coordination of actions and policy responses during future infectious disease outbreaks with empirical evidence. Methods and data We analyzed data on international travel restrictions in response to COVID-19 of 185 countries from January to October 2020. We applied time-to-event analysis to examine the relationship between globalization and the timing of travel restrictions implementation. Results The results of our survival analysis suggest that, in general, more globalized countries, accounting for the country-specific timing of the virus outbreak and other factors, are more likely to adopt international travel restrictions policies. However, countries with high government effectiveness and globalization were more cautious in implementing travel restrictions, particularly if through formal political and trade policy integration. This finding is supported by a placebo analysis of domestic NPIs, where such a relationship is absent. Additionally, we find that globalized countries with high state capacity are more likely to have higher numbers of confirmed cases by the time a first restriction policy measure was taken. Conclusions The findings highlight the dynamic relationship between globalization and protectionism when governments respond to significant global events such as a public health crisis. We suggest that the observed caution of policy implementation by countries with high government efficiency and globalization is a by-product of commitment to existing trade agreements, a greater desire to ‘learn from others’ and also perhaps of ‘confidence’ in a government’s ability to deal with a pandemic through its health system and state capacity. Our results suggest further research is warranted to explore whether global infectious disease forecasting could be improved by including the globalization index and in particular, the de jure economic and political, and de facto social dimensions of globalization, while accounting for the mediating role of government effectiveness. By acting as proxies for a countries’ likelihood and speed of implementation for international travel restriction policies, such measures may predict the likely time delays in disease emergence and transmission across national borders.

scholarly journals Resource allocation in the Covid-19 health crisis: are Covid-19 preventive measures consistent with the Rule of Rescue?

2021 ◽  
Author(s):  
Julian W. März ◽  
Søren Holm ◽  
Michael Schlander
Keyword(s):  
Resource Allocation ◽  
Large Scale ◽  
Preventive Measures ◽  
Risk Groups ◽  
Healthcare Resources ◽  
Health Crisis ◽  
Rule Of Rescue ◽  
Post War ◽  
Vaccination Campaigns ◽  
N95 Respirators

AbstractThe Covid-19 pandemic has led to a health crisis of a scale unprecedented in post-war Europe. In response, a large amount of healthcare resources have been redirected to Covid-19 preventive measures, for instance population-wide vaccination campaigns, large-scale SARS-CoV-2 testing, and the large-scale distribution of protective equipment (e.g., N95 respirators) to high-risk groups and hospitals and nursing homes. Despite the importance of these measures in epidemiological and economic terms, health economists and medical ethicists have been relatively silent about the ethical rationales underlying the large-scale allocation of healthcare resources to these measures. The present paper seeks to encourage this debate by demonstrating how the resource allocation to Covid-19 preventive measures can be understood through the paradigm of the Rule of Rescue, without claiming that the Rule of Rescue is the sole rationale of resource allocation in the Covid-19 pandemic.

Synergising International Public Health Law and International Disaster Law

2020 ◽  
pp. 1-11
Author(s):  
Pratik DIXIT
Keyword(s):  
Public Health ◽  
International Health ◽  
Health Law ◽  
Global Public Health ◽  
Public Health Law ◽  
Health Crisis ◽  
Response Strategies ◽  
Public Health Crisis ◽  
International Public Health ◽  
Health Regulations

There is no time more opportune to review the workings of the International Health Regulations (IHR) than the present COVID-19 crisis. This article analyses the theoretical and practical aspects of international public health law (IPHL), particularly the IHR, to argue that it is woefully unprepared to protect human rights in times of a global public health crisis. To rectify this, the article argues that the IHR should design effective risk reduction and response strategies by incorporating concepts from international disaster law (IDL). Along similar lines, this article suggests that IDL also has a lot to learn from IPHL in terms of greater internationalisation and institutionalisation. Institutionalisation of IDL on par with IPHL will provide it with greater legitimacy, transparency and accountability. This article argues that greater cross-pollination of ideas between IDL and IPHL is necessary in order to make these disciplines more relevant for the future.

scholarly journals Measles Outbreak Associated With Low Vaccine Effectiveness Among Adults in Pohnpei State, Federated States of Micronesia, 2014

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Craig M. Hales ◽  
Eliaser Johnson ◽  
Louisa Helgenberger ◽  
Mark J. Papania ◽  
Maribeth Larzelere ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Vaccination Campaign ◽  
Vaccine Effectiveness ◽  
Mass Vaccination ◽  
Cold Chain ◽  
Primary Case ◽  
Federated States Of Micronesia ◽  
Measles Outbreak ◽  
Mass Vaccination Campaign ◽  
Vaccination Campaigns

Abstract Background.  A measles outbreak in Pohnpei State, Federated States of Micronesia in 2014 affected many persons who had received ≥1 dose of measles-containing vaccine (MCV). A mass vaccination campaign targeted persons aged 6 months to 49 years, regardless of prior vaccination. Methods.  We evaluated vaccine effectiveness (VE) of MCV by comparing secondary attack rates among vaccinated and unvaccinated contacts after household exposure to measles. Results.  Among 318 contacts, VE for precampaign MCV was 23.1% (95% confidence interval [CI], −425 to 87.3) for 1 dose, 63.4% (95% CI, −103 to 90.6) for 2 doses, and 95.9% (95% CI, 45.0 to 100) for 3 doses. Vaccine effectiveness was 78.7% (95% CI, 10.1 to 97.7) for campaign doses received ≥5 days before rash onset in the primary case and 50.4% (95% CI, −52.1 to 87.9) for doses received 4 days before to 3 days after rash onset in the primary case. Vaccine effectiveness for most recent doses received before 2010 ranged from 51% to 57%, but it increased to 84% for second doses received in 2010 or later. Conclusions.  Low VE was a major source of measles susceptibility in this outbreak; potential reasons include historical cold chain inadequacies or waning of immunity. Vaccine effectiveness of campaign doses supports rapid implementation of vaccination campaigns in outbreak settings.

scholarly journals Using geospatial models to map zero-dose children: factors associated with zero-dose vaccination status before and after a mass measles and rubella vaccination campaign

2021 ◽  
Author(s):  
Rohan Arambepola ◽  
Yangyupei Yang ◽  
Kyle Hutchinson ◽  
Francis D Mwansa ◽  
Julie Ann Doherty ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Fine Scale ◽  
Healthcare Facilities ◽  
Factors Associated ◽  
Catchment Areas ◽  
Before And After ◽  
Childhood Vaccines ◽  
A Prospective Study ◽  
Vaccination Campaigns ◽  
The Impact

Introduction: Despite gains in global coverage of childhood vaccines, many children remain undervaccinated. Vaccination campaigns also known as Supplemental Immunization Activity (SIA) are commonly conducted to reach those who are undervaccinated. However, reaching these children even during an SIA is challenging. We evaluated the effectiveness of an SIA in reaching zero dose children. Methods: We conducted a prospective study in 10 health center catchment areas in Southern province, Zambia in November 2020. About 2 months before the measles and rubella SIA we developed aerial satellite maps which were then used to enumerate and survey households. Zero dose children were identified during this exercise. After the SIA, households with zero dose children identified before the SIA were targeted for mop up vaccination and to assess if they were vaccinated during the SIA. A Bayesian geospatial model was used to identify factors associated with zero-dose status before the campaign and produce fine-scale prevalence maps. Models were used to identify factors associated with measles zero-dose children reached in the campaign and identify optimal locations for additional vaccination sites. Results: Before the vaccination campaign, 4% of children under 9 months were DTP zero-dose and 17% of children 9-60 months were measles zero-dose. Of the 461 measles zero-dose children identified before the vaccination campaign, 338 (73.3%) were vaccinated during the campaign, 118 (25.6%) were reached by a targeted mop-up activity. The presence of other children in the household, younger age, greater travel time to health facilities, and living between health facility catchment areas were associated with zero-dose status. Mapping zero-dose prevalence revealed substantial heterogeneity, both within and between catchment areas. Several potential locations were identified for additional vaccination sites. Conclusion: Fine-scale variation in zero-dose prevalence and the impact of accessibility to healthcare facilities on vaccination coverage were identified. Geospatial modeling can aid targeted vaccination activities.

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