scholarly journals Predicting the impact of COVID-19 vaccination campaigns - a flexible age-dependent, spatially-stratified predictive model, accounting for multiple viral variants and vaccines

2022 ◽  
Author(s):  
Kristan Alexander Schneider ◽  
Henri Christian Junior Tsoungui Obama ◽  
Nessma Adil Mahmoud Yousif ◽  
Pierre Marie Ngougoue Ngougoue
Keyword(s):  
Herd Immunity ◽  
Risk Groups ◽  
Vaccination Schedule ◽  
Dimensional System ◽  
Vaccination Rates ◽  
Low Incidence ◽  
Mandatory Vaccination ◽  
Vaccination Campaigns ◽  
Low Coverage ◽  
The Impact

Background: After COVID-19 vaccines received approval, vaccination campaigns were launched worldwide. Initially, these were characterized by a shortage of vaccine supply, and specific risk groups were prioritized. Once supply was guaranteed and vaccination coverage saturated, the focus shifted from risk groups to anti-vaxxers, the underaged population, and regions of low coverage. At the same time, hopes to reach herd immunity by vaccination campaigns were put into perspective by the emergence and spread of more contagious and aggressive viral variants. Particularly, concerns were raised that not all vaccines protect against the new-emerging variants. Methods and findings: A model designed to predict the effect of vaccination campaigns on the spread of viral variants is introduced. The model is a comprehensive extension of the model underlying the pandemic preparedness tool CovidSim 2.0 (http://covidsim.eu/). The model is age and spatially stratified, incorporates a finite (but arbitrary) number of different viral variants, and incorporates different vaccine products. The vaccines are allowed to differ in their vaccination schedule, vaccination rates, the onset of vaccination campaigns, and their effectiveness. These factors are also age and/or location dependent. Moreover, the effectiveness and the immunizing effect of vaccines are assumed to depend on the interaction of a given vaccine and viral variant. Importantly, vaccines are not assumed to immunize perfectly. Individuals can be immunized completely, only partially, or fail to be immunized against one or many viral variants. Not all individuals in the population are vaccinable. The model is formulated as a high-dimensional system of differential equations, which is implemented efficiently in the programming language Julia. As an example, the model was parameterized to reflect the epidemic situation in Germany until November 2021 and predicted the future dynamics of the epidemic under different interventions. In particular, without tightening contact reductions, a strong epidemic wave is predicted. At the current state, mandatory vaccination would be too late to have a strong effect on reducing the number of infections. However, it would reduce mortality. An emergency brake, i.e., an incidence-based stepwise lockdown would be efficient to reduce the number of infections and mortality. Furthermore, to specifically account for mobility between regions, the model was applied to two German provinces of particular interest: Saxony, which currently has the lowest vaccine rollout in Germany and high incidence, and Schleswig-Holstein, which has high vaccine rollout and low incidence. Conclusions: A highly sophisticated and flexible but easy-to-parameterize model for the ongoing COVID-19 pandemic is introduced. The model is capable of providing useful predictions for the COVID-19 pandemic, and hence provides a relevant tool for epidemic decision-making. The model can be adjusted to any country, to derive the demand for hospital and ICU capacities as well as economic collateral damages.

Voluntary to Mandatory: Evolution of Strategies and Attitudes toward Influenza Vaccination of Healthcare Personnel

2012 ◽  
Vol 33 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Kathleen Quan ◽  
David M. Tehrani ◽  
Linda Dickey ◽  
Eugene Spiritus ◽  
Denise Hizon ◽  
...  
Keyword(s):  
Influenza Vaccination ◽  
Vaccination Campaign ◽  
Vaccine Uptake ◽  
Healthcare Personnel ◽  
Vaccination Policy ◽  
Vaccination Rates ◽  
Hospital Policies ◽  
Mandatory Vaccination ◽  
Vaccination Campaigns ◽  
The Impact

Background.Assessing the relative success of serial strategies for increasing healthcare personnel (HCP) influenza vaccination rates is important to guide hospital policies to increase vaccine uptake.Objective.To evaluate serial campaigns that include a mandatory HCP vaccination policy and to describe HCP attitudes toward vaccination and reasons for declination.Design.Retrospective cohort study.Methods.We assessed the impact of serial vaccination campaigns on the proportions of HCP who received influenza vaccination during die 2006–2011 influenza seasons. In addition, declination data over these 5 seasons and a 2007 survey of HCP attitudes toward vaccination were collected.Results.HCP influenza vaccination rates increased from 44.0% (2,863 of 6,510 HCP) to 62.9% (4,037 of 6,414 HCP) after institution of mobile carts, mandatory declination, and peer-to-peer vaccination efforts. Despite maximal attempts to improve accessibility and convenience, 27.2% (66 of 243) of die surveyed HCP were unwilling to wait more than 10 minutes for a free influenza vaccination, and 23.3% (55 of 236) would be indifferent if they were unable to be vaccinated. In this context, institution of a mandatory vaccination campaign requiring unvaccinated HCP to mask during the influenza season increased rates of compliance to over 90% and markedly reduced the proportion of HCP who declined vaccination as a result of preference.Conclusions.A mandatory influenza vaccination program for HCP was essential to achieving high vaccination rates, despite years of intensive vaccination campaigns focused on increasing accessibility and convenience. Mandatory vaccination policies appear to successfully capture a large portion of HCP who are not opposed to receipt of die vaccine but who have not made vaccination a priority.Infect Control Hosp Epidemiol 2012;33(1):63-70

scholarly journals The Effect of Vaccination Rates on the Infection of COVID-19 under the Vaccination Rate below the Herd Immunity Threshold

2021 ◽  
Vol 18 (14) ◽  
pp. 7491
Author(s):  
Yi-Tui Chen
Keyword(s):  
Infection Rate ◽  
Herd Immunity ◽  
The United States ◽  
Vaccination Rate ◽  
Infection Rates ◽  
Vaccination Rates ◽  
The United Kingdom ◽  
The World ◽  
Almost All ◽  
The Impact

Although vaccination is carried out worldwide, the vaccination rate varies greatly. As of 24 May 2021, in some countries, the proportion of the population fully vaccinated against COVID-19 has exceeded 50%, but in many countries, this proportion is still very low, less than 1%. This article aims to explore the impact of vaccination on the spread of the COVID-19 pandemic. As the herd immunity of almost all countries in the world has not been reached, several countries were selected as sample cases by employing the following criteria: more than 60 vaccine doses per 100 people and a population of more than one million people. In the end, a total of eight countries/regions were selected, including Israel, the UAE, Chile, the United Kingdom, the United States, Hungary, and Qatar. The results find that vaccination has a major impact on reducing infection rates in all countries. However, the infection rate after vaccination showed two trends. One is an inverted U-shaped trend, and the other is an L-shaped trend. For those countries with an inverted U-shaped trend, the infection rate begins to decline when the vaccination rate reaches 1.46–50.91 doses per 100 people.

ADDRESSING COVID-19 IN KAZAKHSTAN: WHAT ARE THE EFFORTS AND CHALLENGES?

Vestnik ◽  
2021 ◽  
pp. 289-292
Author(s):  
Л.Ж. Алекешева ◽  
К.К. Тогузбаева ◽  
К.О. Джусупов
Keyword(s):  
Social Services ◽  
Herd Immunity ◽  
Health Indicators ◽  
Risk Groups ◽  
Medical Services ◽  
New Disease ◽  
Optimal Care ◽  
Number Of Patients ◽  
Coronavirus Infection ◽  
The Impact

COVID-19 нанес серьезный удар по системам здравоохранения многих стран мира, включая Республику Казахстан. Чтобы справиться с пандемией, Казахстан разработал план, содержащий три стратегические цели: 1) предотвращение вспышки болезни; 2) Обеспечение оптимального ухода для всех пациентов и 3) Сведение к минимуму воздействия пандемии на системы здравоохранения, социальные услуги и экономическую деятельность. Однако неравномерное распределение финансовых ресурсов по регионам, нерегулярное потребление медицинских услуг и различия в показателях здоровья препятствуют этим усилиям. Другие проблемы - это нехватка медицинских сил, неожиданность ситуации, отсутствие знаний о коронавирусной инфекции и бессилие перед этой новой болезнью. Были трудности с массовым тестированием, поскольку стигма и страх перед карантином вынуждали людей не проходить тестирование. После отмены чрезвычайного положения и строгой изоляции страну охватила эйфория, которая привела к резкому увеличению числа случаев заболевания. Чтобы взять ситуацию под контроль в июне 2020 года был экстренно введен второй локдаун, постепенно стало уменьшаться количество больных и инфицированных. Пандемия показала, насколько хрупка и зависима система: была отложена плановая вакцинация детям до 1 года, временно приостановлено медицинское обследование и оказание медицинских услуг больным хроническими, онкологическими заболеваниями, плановая госпитализация. Многие врачи и медсестры заразились и заболели. На момент написания этой статьи эпидемиологическая ситуация в стране с COVID-19 находится под контролем и надзором, однако давать какие-либо прогнозы относительно его завершения пока рано. Казахстан готовится к вакцинации от коронавирусной инфекции, в первую очередь вакцинации должны подвергаться группы риска, медицинские и социальные работники, а также люди с хроническими заболеваниями. Пока коллективный иммунитет не сформирован, казахстанцы должны проявлять осторожность при снятии ограничений, чтобы предотвратить взрыв новых случаев заболевания. COVID-19 has strained the healthcare systems of many countries worldwide including the Republic of Kazakhstan. To cope with the pandemic, Kazakhstan mounted a plan containing three strategic objectives: 1) Preventing the outbreak of the disease; 2) Ensuring optimal care for all patients, and 3) Minimizing the impact of the pandemic on health systems, social services, and economic activities. However, the uneven distribution of financial resources across regions, irregular consumption of medical services, and inconsistent health indicators hamper these efforts. Other issues are the lack of medical forces, the unexpectedness of the situation, lack of knowledge on coronavirus infection, and powerlessness in front of this new disease. There were difficulties in mass testing as stigma and fear from quarantine forced people not to get tested. The euphoria enveloped the country after abolishing the emergency state after an intense lockdown which resulted in increased cases. A second lockdown was urgently introduced in June 2020 to take control of the situation. The number of patients and those infected gradually began to decline. The pandemic showed the fragility and inter-dependence of the health system- planned vaccinations against many infectious diseases were postponed. Medical examination and provision of medical services to patients with chronic, oncological diseases, planned hospitalization were temporarily halted. Many doctors and nurses became infected and ill. The country's COVID-19 epidemiological situation is somewhat under the control and supervision as of this writing. However, to give any forecasts for its completion is still too early. Kazakhstan is preparing to vaccinate against coronavirus infection. First of all, risk groups, medical and social workers, and people with chronic diseases should be subject to vaccination. Until herd immunity is not formed, Kazakhstanis must keep caution when the restrictions are taken off to prevent an explosion of new disease cases.

Ethical Considerations and Practical Implications in Romanian Covid-19 Vaccination Campaign

2021 ◽  
Vol 66 (Special Issue) ◽  
pp. 156-157
Author(s):  
Petru Sandu ◽  
◽  
Maria Aluaș ◽  
Răzvan M. Cherecheș ◽  
◽  
...  
Keyword(s):  
Public Health ◽  
Vaccination Campaign ◽  
European Countries ◽  
Ethical Considerations ◽  
Vaccination Rates ◽  
One Year ◽  
High Level ◽  
Vaccination Campaigns ◽  
The Impact ◽  
Practical Implications

"Besides its undoubtable significant contribution to morbidity and mortality worldwide, the COVID-19 pandemic has had numerous political, social, economic, and public health implications. Vaccination, an already long debated public health ethics theme, has reoccurred in force, as the efforts of the scientific community to curb the pandemic resulted in a viable vaccine less than one year since COVID-19 was declared a pandemic. High-level, international negotiations dictated states’ COVID-19 vaccine availability in the first few months, therefore each national Government had to develop and deploy vaccination campaigns prioritizing certain population categories. This paper aims to present Romanian COVID-19 vaccination campaign, from its inception to the present days, by focusing on the ethical considerations (e.g. prioritization, coercion, non-discrimination) and their practical implications ( e.g. vaccination hesitancy, rates, fake news). Like most countries in the European Community, Romania has initially adopted a Rawlsian approach to vaccination, prioritizing the older adults and the individuals with chronic conditions. However, unlike other European countries, coercion was not considered in any form (e.g. extended mobility facilities for the vaccinated), more recently incentives such as food vouchers being discussed. The impact of these decisions on the vaccination rates and hesitancy are discussed in the context of other European countries examples of vaccination campaigns. "

scholarly journals The importance of sustained compliance with physical distancing during COVID-19 vaccination rollout

2021 ◽  
Author(s):  
Alexandra Teslya ◽  
Ganna Rozhnova ◽  
Thi Mui Pham ◽  
Daphne van Wees ◽  
Hendrik Nunner ◽  
...  
Keyword(s):  
Vaccination Coverage ◽  
Vaccine Coverage ◽  
Transmission Model ◽  
Cumulative Number ◽  
Vaccination Rates ◽  
Contact Rates ◽  
Health Authorities ◽  
Public Health Authorities ◽  
Vaccination Campaigns ◽  
The Impact

Abstract Mass vaccination campaigns against SARS-CoV-2 are under way in many countries with the hope that increasing vaccination coverage will enable reducing current physical distancing measures. Compliance with these measures is waning, while more transmissible virus variants such as B.1.1.7 have emerged. Using SARS-CoV-2 transmission model we investigated the impact of the feedback between compliance, the incidence of infection, and vaccination coverage on the success of a vaccination programme in the population where waning of compliance depends on vaccine coverage. Our results suggest that the combination of fast waning compliance, slow vaccination rates, and more transmissible variants may result in a higher cumulative number of infections than in a situation without vaccination. These adverse effects can be alleviated if vaccinated individuals do not revert to pre-pandemic contact rates, and if non-vaccinated individuals remain compliant with physical distancing measures. Both require convincing, clear and appropriately targeted communication strategies by public health authorities.

scholarly journals Mathematical modeling of endemic cholera transmission

2021 ◽  
Author(s):  
Dennis L Chao
Keyword(s):  
Mathematical Modeling ◽  
Herd Immunity ◽  
Population Level ◽  
Additional Benefit ◽  
Mass Vaccination ◽  
The Cost ◽  
Vaccination Campaigns ◽  
The Impact ◽  
Indirect Protection ◽  
Endemic Cholera

Abstract Mathematical modeling can be used to project the impact of mass vaccination on cholera transmission. Here, we discuss two examples for which indirect protection from mass vaccination needs to be considered. In the first, we show that non-vaccinees can be protected by mass vaccination campaigns. This additional benefit of indirect protection improves the cost-effectiveness of mass vaccination. In the second, we model the use of mass vaccination to eliminate cholera. In this case, a high population level of immunity, including contributions from infection and vaccination, is required to reach the “herd immunity” threshold needed to stop transmission and achieve elimination.

scholarly journals Comparison between one and two dose SARS-CoV-2 vaccine prioritization for a fixed number of vaccine doses

2021 ◽  
Vol 18 (182) ◽  
pp. 20210214
Author(s):  
Edward M. Hill ◽  
Matt J. Keeling
Keyword(s):  
Phase 1 ◽  
Vaccine Dose ◽  
Optimal Dose ◽  
Risk Groups ◽  
Vaccination Schedule ◽  
Careful Consideration ◽  
Fixed Number ◽  
Vaccination Rates ◽  
Risk Of Mortality ◽  
Priority Order

The swift development of SARS-CoV-2 vaccines has been met with worldwide commendation. However, in the context of an ongoing pandemic there is an interplay between infection and vaccination. While infection can grow exponentially, vaccination rates are generally limited by supply and logistics. With the first SARS-CoV-2 vaccines receiving medical approval requiring two doses, there has been scrutiny on the spacing between doses; an elongated period between doses allows more of the population to receive a first vaccine dose in the short-term generating wide-spread partial immunity. Focusing on data from England, we investigated prioritization of a one dose or two dose vaccination schedule given a fixed number of vaccine doses and with respect to a measure of maximizing averted deaths. We optimized outcomes for two different estimates of population size and relative risk of mortality for at-risk groups within the Phase 1 vaccine priority order. Vaccines offering relatively high protection from the first dose favour strategies that prioritize giving more people one dose, although with increasing vaccine supply eventually those eligible and accepting vaccination will receive two doses. While optimal dose timing can substantially reduce the overall mortality risk, there needs to be careful consideration of the logistics of vaccine delivery.

scholarly journals BNT162b2 mRNA COVID-19 Vaccine Effectiveness in the Prevention of SARS-CoV-2 Infection and Symptomatic Disease in Five-Month Follow-Up: A Retrospective Cohort Study

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1143
Author(s):  
Francesco Bianchi ◽  
Silvio Tafuri ◽  
Giovanni Migliore ◽  
Luigi Vimercati ◽  
Andrea Martinelli ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Vaccination Schedule ◽  
Vaccine Effectiveness ◽  
University Hospital ◽  
Symptomatic Disease ◽  
Vaccination Rates ◽  
Mass Vaccination Campaign ◽  
Mandatory Vaccination

To combat the COVID-19 pandemic, a mass vaccination campaign was initiated in Italy on 27 December 2020. The vaccine available to immunize Italian healthcare workers (HCWs) was the BNT162b2 mRNA COVID-19 vaccine (Comirnaty). This study evaluated the effectiveness of the vaccine against documented SARS-CoV-2 infection and symptomatic diseases in the medium- to long-term. HCWs at Bari Policlinico University-Hospital (Italy) who completed the vaccination schedule were matched with HCWs who had refused vaccination; the two groups were followed-up for 5 months (January–May 2021). Vaccine effectiveness (VE) against infection was 97.7% (95.4–99.0%) at 14–34 days after the first dose, and 94.8% (87.0–97.8%), 83.0% (65.0–92.0%), and 81.0% (42.0–94.0%) at 14–41, 42–69, and >69 days, respectively, after the second dose. The estimated VE for documented symptomatic disease was 99.2% (96.4–99.8%) at 14–34 days after the first dose and 97.2% (90.3–99.2%), 85.0% (63.0–94.2%), and 88.0% (42.0–97.6%) at 14–41, 42–69, and >69 days, respectively, after the second dose. Efforts to increase vaccination rates should be strengthened, including mandatory vaccination for HCWs and greater incentives to increase vaccine acceptance by the general population.

scholarly journals Comparison between one and two dose SARS-CoV-2 vaccine prioritisation for a fixed number of vaccine doses

2021 ◽  
Author(s):  
Edward M. Hill ◽  
Matt J. Keeling
Keyword(s):  
Phase 1 ◽  
Vaccine Dose ◽  
Risk Groups ◽  
Vaccination Schedule ◽  
Careful Consideration ◽  
Fixed Number ◽  
Optimal Timing ◽  
Vaccination Rates ◽  
Risk Of Mortality ◽  
Optimal Mix

AbstractBackgroundThe swift development of vaccines targeting SARS-CoV-2, which have been shown to generate significant immune responses and offer considerable protection against disease, has been met with worldwide commendation. However, in the context of an ongoing pandemic there is an interplay between infection and vaccination. While infection can grow exponentially, potentially overwhelming healthcare resources, vaccination rates are generally limited by both supply and logistics. With the first SARS-CoV-2 vaccines receiving medical approval requiring two doses, there has been scrutiny on the spacing between doses; an elongated period between doses would allow more of the population to receive a first vaccine dose in the short-term generating wide-spread partial immunity.MethodsFocusing on data from England, we investigated prioritisation of a one dose or two dose vaccination schedule given a fixed number of vaccine doses and with respect to a measure of maximising averted deaths. We optimised outcomes for two different estimates of population size and relative risk of mortality for at-risk groups within the Phase 1 vaccine priority order in England, for different amounts of available vaccine and for different vaccine efficacies.FindingsWe find that vaccines offering relatively high protection from the first dose (compared to the efficacy derived from two doses) favour strategies that prioritise giving more people one dose rather than a smaller number two. The optimal mix of one and two doses between the defined priority groups of Phase 1 shows a pattern of returning to give second doses to the highest risk groups as the number of available doses increases.DiscussionWhile this work highlights that an optimal timing of first and second doses between the Phase 1 priority groups can substantially reduce the overall mortality risk to the population, there also needs to be careful consideration of the precise timing between first and second doses as well as the logistics of vaccine delivery.

scholarly journals Sustained low rotavirus activity and hospitalisation rates in the post-vaccination era in Belgium, 2007 to 2014

2016 ◽  
Vol 21 (27) ◽  
Author(s):  
Martine Sabbe ◽  
Nicolas Berger ◽  
Adriaan Blommaert ◽  
Benson Ogunjimi ◽  
Tine Grammens ◽  
...  
Keyword(s):  
Herd Immunity ◽  
Vaccination Schedule ◽  
Vaccine Uptake ◽  
Age Group ◽  
The European Union ◽  
Post Vaccination ◽  
Rotavirus Vaccination ◽  
Rotavirus Gastroenteritis ◽  
The Impact ◽  
Vaccination Period

In 2006, Belgium was the first country in the European Union to recommend rotavirus vaccination in the routine infant vaccination schedule and rapidly achieved high vaccine uptake (86–89% in 2007). We used regional and national data sources up to 7 years post-vaccination to study the impact of vaccination on laboratory-confirmed rotavirus cases and rotavirus-related hospitalisations and deaths. We showed that (i) from 2007 until 2013, vaccination coverage remained at 79–88% for a complete course, (ii) in children 0–2 years, rotavirus cases decreased by 79% (95% confidence intervals (CI): 68–­89%) in 2008–2014 compared to the pre-vaccination period (1999–­2006) and by 50% (95% CI: 14–82%) in the age group ≥ 10 years, (iii) hospitalisations for rotavirus gastroenteritis decreased by 87% (95% CI: 84–90%) in 2008–­2012 compared to the pre-vaccination period (2002–­2006), (iv) median age of rotavirus cases increased from 12 months to 17 months and (v) the rotavirus seasonal peak was reduced and delayed in all post-vaccination years. The substantial decline in rotavirus gastroenteritis requiring hospitalisations and in rotavirus activity following introduction of rotavirus vaccination is sustained over time and more pronounced in the target age group, but with evidence of herd immunity.

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