scholarly journals Predicting the impact of pneumococcal conjugate vaccine programme options in Vietnam: a dynamic transmission model

2017 ◽  
Author(s):  
Olivier Le Polain De Waroux ◽  
W. John Edmunds ◽  
Kensuke Takahashi ◽  
Koya Ariyoshi ◽  
E. Kim Mulholland ◽  
...  
Keyword(s):  
Age Groups ◽  
Social Contact ◽  
Transmission Model ◽  
Local Data ◽  
Complete Replacement ◽  
Vaccine Introduction ◽  
Dynamic Transmission Model ◽  
Vaccine Type ◽  
Catch Up ◽  
The Impact

ABSTRACTBackgroundCatch-up campaigns (CCs) at the introduction of the pneumococcal conjugate vaccines (PCVs) may accelerate the impact of PCVs. However, limited vaccine supplies may delay vaccine introduction if additional doses are needed for such campaigns. We studied the relative impact of introducing PCV13 with and without catch-up campaign, and the implications of potential introduction delays.MethodsWe used a dynamic transmission model applied to the population of Nha Trang in Sout central Vietnam. Four strategies were considered: routine vaccination (RV) only, and RV alongside catch-up campaigns among <1y olds (CC1), <2y olds (CC2) and <5y olds (CC5). The model was parameterised with local data on human social contact rates, and was fitted to local carriage data. Post-PCV predictions were based on best estimates of parameters governing post-PCV dynamics, including serotype competition, vaccine efficacy and duration of protection.ResultsOur model predicts elimination of vaccine-type (VT) carriage across all age groups within 10 years of introduction in all scenarios with near-complete replacement by non-VT. Most of the benefit of CCs is predicted to occur within the first 3 years after introduction, with the highest impact in the first year, when IPD incidence is predicted to be 11% (95%CrI 9 – 14%) lower than RV with CC1, 25% (21 – 30 %) lower with CC2 and 38% (32 – 46%) lower with CC5.However, CCs would only prevent more cases of IPD insofar such campaigns do not delay introduction by more than 31 (95%CrI 30 – 32) weeks with CC1, 58 (53 – 63) weeks with CC2 and 89 (78 – 101) weeks for CC5.ConclusionCCs are predicted to offer a substantial additional reduction in pneumococcal disease burden over RV alone, if their implementation does not result in much introduction delay. Those findings are important to help guide vaccine introduction in countries that have not yet introduced PCV, particularly in Asia.

scholarly journals Vaccinating Adolescents and Children Significantly Reduces COVID-19 Morbidity and Mortality across All Ages: A Popula-Tion-Based Modeling Study Using the UK as an Example

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1180
Author(s):  
Tinevimbo Shiri ◽  
Marc Evans ◽  
Carla A. Talarico ◽  
Angharad R. Morgan ◽  
Maaz Mussad ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Age Groups ◽  
Population Level ◽  
Vital Role ◽  
Morbidity And Mortality ◽  
Transmission Model ◽  
Base Case ◽  
Global Public Health ◽  
The Uk ◽  
The Impact

Debate persists around the risk–benefit balance of vaccinating adolescents and children against COVID-19. Central to this debate is quantifying the contribution of adolescents and children to the transmission of SARS-CoV-2, and the potential impact of vaccinating these age groups. In this study, we present a novel SEIR mathematical disease transmission model that quantifies the impact of different vaccination strategies on population-level SARS-CoV-2 infections and clinical outcomes. The model employs both age- and time-dependent social mixing patterns to capture the impact of changes in restrictions. The model was used to assess the impact of vaccinating adolescents and children on the natural history of the COVID-19 pandemic across all age groups, using the UK as an example. The base case model demonstrates significant increases in COVID-19 disease burden in the UK following a relaxation of restrictions, if vaccines are limited to those ≥18 years and vulnerable adolescents (≥12 years). Including adolescents and children in the vaccination program could reduce overall COVID-related mortality by 57%, and reduce cases of long COVID by 75%. This study demonstrates that vaccinating adolescents and children has the potential to play a vital role in reducing SARS-CoV-2 infections, and subsequent COVID-19 morbidity and mortality, across all ages. Our results have major global public health implications and provide valuable information to inform a potential pandemic exit strategy.

scholarly journals Mathematical Models for Assessing Vaccination Scenarios in Several Provinces in Indonesia

2020 ◽  
Author(s):  
N. Nuraini ◽  
K. Khairudin ◽  
P. Hadisoemarto ◽  
H. Susanto ◽  
A. Hasan ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Age Groups ◽  
Transmission Model ◽  
West Java ◽  
Dynamic Transmission Model ◽  
Simulation Results ◽  
Age Structured

AbstractTo mitigate more casualties from the COVID-19 outbreak, this study assessed optimal vaccination scenarios, considering some existing healthcare conditions and some assumptions, by developing SIQRD (Susceptible-Infected-Quarantine-Recovery-Death) models for Jakarta, West Java, and Banten, in Indonesia. The models included an age-structured dynamic transmission model that naturally could give different treatments among age groups of population. The simulation results show that the timing and period’s length of the vaccination should be well planned and prioritizing particular age groups will give significant impact on the total number of casualties.

scholarly journals FACE-TO-FACE AND FACEBOOK ACROSS THE LIFESPAN: SOCIAL INTERACTIONS BUFFER STRESS ON MOOD, BUT ONLY FOR ADOLESCENTS

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S694-S695
Author(s):  
Yin Liu ◽  
Elizabeth B Fauth ◽  
Myles Maxey ◽  
Troy Beckert
Keyword(s):  
Social Support ◽  
Social Media ◽  
Protective Factor ◽  
Stress Reactivity ◽  
Age Groups ◽  
Social Contact ◽  
Developmental Differences ◽  
Stress Appraisal ◽  
Face To Face ◽  
The Impact

Abstract Social support serves as a protective factor, buffering stress in both adolescents and adults, however Socioemotional Selectivity Theory suggests developmental differences in stress reactivity and social support. It is unclear how modern forms of social contact, such as social media buffer stress, and the extent to which this differs across the lifespan. We utilized ecological momentary data to examine the moderating effects of age and two distinct types of social contacts the person had experienced in prior hours (frequency of face-to-face, or social media contacts) on the association between daily stress and momentary mood. Participants were recruited initially through Amazon.com’s Mechanical Turk (adolescents referred by a parent). A total of 119 adolescent (n = 44; Agemean= 15.73) and middle-aged/older adult participants (n = 75; Agemean= 59.67) provided momentary data three times a day, on three consecutive days, every two weeks, for up to 12 weeks. Multi-level models showed significant 3-way interactions between stress appraisal of avoiding an argument, age group, and frequency of social contact via face-to-face (β = 1.698, se = 0.542, p = .002) and social media (β = 3.341, se = 0.984, p = .001). Older adults experienced better mood than adolescents. When avoiding an argument was appraised as more stressful, both age groups displayed worse mood. Whereas high levels of recent social contact (both face-to-face and social media) seemed to exacerbate the impact of this stressor on poorer mood for older persons, high levels of recent social contact, particularly social media, had stress-buffering benefits for adolescents.

scholarly journals Modelling control measures to reduce the impact of pandemic influenza among schoolchildren

2007 ◽  
Vol 136 (8) ◽  
pp. 1035-1045 ◽  
Author(s):  
S.-C. CHEN ◽  
C.-M. LIAO
Keyword(s):  
Elementary School ◽  
Pandemic Influenza ◽  
Age Groups ◽  
Integrated Approach ◽  
Control Measures ◽  
Transmission Model ◽  
Transmission Potential ◽  
Vaccination Coverage Rate ◽  
Control Programmes ◽  
The Impact

SUMMARYWe coupled the Wells–Riley equation and the susceptible–exposed–infected–recovery (SEIR) model to quantify the impact of the combination of indoor air-based control measures of enhanced ventilation and respiratory masking in containing pandemic influenza within an elementary school. We integrated indoor environmental factors of a real elementary school and aetiological characteristics of influenza to estimate the age-specific risk of infection (P) and basic reproduction number (R0). We combined the enhanced ventilation rates of 0·5, 1, 1·5, and 2/h and respiratory masking with 60%, 70%, 80%, and 95% efficacies, respectively, to predict the reducing level of R0. We also took into account the critical vaccination coverage rate among schoolchildren. Age-specific P and R0 were estimated respectively to be 0·29 and 16·90; 0·56 and 16·11; 0·59 and 12·88; 0·64 and 16·09; and 0·07 and 2·80 for five age groups 4–6, 7–8, 9–10, 11–12, and 25–45 years, indicating pre-schoolchildren have the highest transmission potential. We conclude that our integrated approach, employing the mechanism of transmission of indoor respiratory infection, population-dynamic transmission model, and the impact of infectious control programmes, is a powerful tool for risk profiling prediction of pandemic influenza among schoolchildren.

scholarly journals Sex differences in invasive pneumococcal disease and the impact of pneumococcal conjugate vaccination in the Netherlands, 2004 to 2015

2017 ◽  
Vol 22 (10) ◽  
Author(s):  
Gertjan H J Wagenvoort ◽  
Elisabeth A M Sanders ◽  
Bart J Vlaminckx ◽  
Hester E de Melker ◽  
Arie van der Ende ◽  
...  
Keyword(s):  
Sex Differences ◽  
The Netherlands ◽  
Invasive Pneumococcal Disease ◽  
Pneumococcal Disease ◽  
Age Groups ◽  
Temporary Increase ◽  
Long Term Effects ◽  
Vaccine Introduction ◽  
Ongoing Surveillance ◽  
The Impact

Implementation of pneumococcal conjugate vaccines in the Netherlands (PCV7 in 2006 and PCV10 in 2011) for infants caused a shift in serotypes in invasive pneumococcal disease (IPD). We explored sex differences in serotype-specific IPD incidence before and after vaccine introduction. Incidences in the pre-PCV7 (June 2004–May 2006), post-PCV7 (June 2008–May 2011) and post-PCV10 period (June 2013–May 2015), stratified by age, were compared. Incidence was higher in men for all age groups (overall in men: 16.7, 15.5 and 14.4/100,000 and women: 15.4, 13.6 and 13.9/100,000 pre-PCV7, post-PCV7 and post-PCV10, respectively), except for 20–39 year-olds after PCV7 and 40–64 year-olds after PCV10 introduction. After PCV7 and PCV10 introduction, the overall IPD incidence decreased in men aged 20–39 years (from 5.3 pre-PCV7 to 4.7 and 2.6/100,000 post-PCV7 and post-PCV10, respectively), whereas it showed a temporary increase in women (from 3.9/100,000 pre-PCV7 to 5.0/100,000 post-PCV7 and back to 4.0/100,000 post-PCV10) due to replacement disease. PCV10 herd effects were observed throughout, but in women older than 40 years, a significant increase in non-PCV10 serotype offset a decrease in overall IPD incidence. Ongoing surveillance of IPD incidence by sex is important to evaluate the long-term effects of PCV implementation.

scholarly journals Indigenous Australian household structure: a simple data collection tool and implications for close contact transmission of communicable diseases

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3958 ◽  
Author(s):  
Thiripura Vino ◽  
Gurmeet R. Singh ◽  
Belinda Davison ◽  
Patricia T. Campbell ◽  
Michael J. Lydeamore ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Close Contact ◽  
Age Groups ◽  
Social Contact ◽  
Communicable Diseases ◽  
Household Structure ◽  
Indigenous Populations ◽  
Indigenous Australian ◽  
Different Populations ◽  
The Impact

Households are an important location for the transmission of communicable diseases. Social contact between household members is typically more frequent, of greater intensity, and is more likely to involve people of different age groups than contact occurring in the general community. Understanding household structure in different populations is therefore fundamental to explaining patterns of disease transmission in these populations. Indigenous populations in Australia tend to live in larger households than non-Indigenous populations, but limited data are available on the structure of these households, and how they differ between remote and urban communities. We have developed a novel approach to the collection of household structure data, suitable for use in a variety of contexts, which provides a detailed view of age, gender, and room occupancy patterns in remote and urban Australian Indigenous households. Here we report analysis of data collected using this tool, which quantifies the extent of crowding in Indigenous households, particularly in remote areas. We use these data to generate matrices of age-specific contact rates, as used by mathematical models of infectious disease transmission. To demonstrate the impact of household structure, we use a mathematical model to simulate an influenza-like illness in different populations. Our simulations suggest that outbreaks in remote populations are likely to spread more rapidly and to a greater extent than outbreaks in non-Indigenous populations.

scholarly journals A simulation study on the relative role of age groups under differing pertussis transmission scenarios

2018 ◽  
Author(s):  
Ana I. Bento ◽  
Aaron A. King ◽  
Pejman Rohani
Keyword(s):  
Herd Immunity ◽  
Age Groups ◽  
Transmission Model ◽  
Relative Role ◽  
Older Individuals ◽  
Age Cohorts ◽  
Relative Risks ◽  
Transmission Mechanisms ◽  
Acellular Vaccines ◽  
The Impact

AbstractPertussis has resurged in many countries where it was once regarded as under control, with the recent outbreaks showing a shift in incidence towards teens and older individuals. Here, using an age-stratified transmission model, we tested two potential causes for underlying changes in pertussis transmission dynamics. We did so assuming hypothesized mechanisms supporting present-day pertussis epidemiology: (I) improved diagnostics, (II) acellular vaccines leading to asymptomatic transmission (III) both. We used the relative risks and odds ratio methods to examine the impact of these differing assumptions on signatures of relative roles of key age groups through time, allowing us to explore those age cohorts that disproportionately account for transmission. Our findings show that for epidemics after the vaccine switch, a scenario with increased adult reporting and no asymptomatic transmission reflect a loss of signal, where no age group appears to be key. While scenarios with asymptomatic transmission, reflect a population where children (1-10 years old) are still disproportionally at risk. These results demonstrate that understanding the underlying transmission mechanisms in a population are paramount for vaccination policies in attaining herd immunity and eventually eradication.

scholarly journals Indigenous Australian household structure: a simple data collection tool and implications for close contact transmission of communicable diseases

2017 ◽  
Author(s):  
Thiripura Vino ◽  
Gurmeet R Singh ◽  
Belinda Davison ◽  
Patricia T Campbell ◽  
Michael Lydeamore ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Close Contact ◽  
Age Groups ◽  
Social Contact ◽  
Communicable Diseases ◽  
Household Structure ◽  
Indigenous Populations ◽  
Indigenous Australian ◽  
Different Populations ◽  
The Impact

Households are an important location for the transmission of communicable diseases. Social contact between household members is typically more frequent, of greater intensity, and is more likely to involve people of different age groups than contact occurring in the general community. Understanding household structure in different populations is therefore fundamental to explaining patterns of disease transmission in these populations. Indigenous populations in Australia tend to live in larger households than non Indigenous populations, but limited data is available on the structure of these households, and how they differ between remote and urban communities. We have developed a novel approach to the collection of household structure data, suitable for use in a variety of contexts, which provides a detailed view of age,gender, and room occupancy patterns in remote and urban Australian Indigenous households. Here we report analysis of data collected using this tool, which quantifies the extent of crowding in Indigenous households, particularly in remote areas. We use this data to generate matrices of age-specific contact rates, as used by mathematical models of infectious disease transmission. To demonstrate the impact of household structure, we use a mathematical model to simulate an influenza-like illness in different populations. Our simulations suggest that outbreaks in remote populations are likely to spread more rapidly and to a greater extent than outbreaks in non-Indigenous populations.

scholarly journals Predictions of COVID-19 dynamics in the UK: Short-term forecasting and analysis of potential exit strategies

2021 ◽  
Vol 17 (1) ◽  
pp. e1008619
Author(s):  
Matt J. Keeling ◽  
Edward M. Hill ◽  
Erin E. Gorsich ◽  
Bridget Penman ◽  
Glen Guyver-Fletcher ◽  
...  
Keyword(s):  
Critical Care ◽  
Health Service ◽  
Age Groups ◽  
Transmission Model ◽  
Bed Occupancy ◽  
Time Data ◽  
Social Distancing ◽  
Number Of Patients ◽  
The Uk ◽  
The Impact

Efforts to suppress transmission of SARS-CoV-2 in the UK have seen non-pharmaceutical interventions being invoked. The most severe measures to date include all restaurants, pubs and cafes being ordered to close on 20th March, followed by a “stay at home” order on the 23rd March and the closure of all non-essential retail outlets for an indefinite period. Government agencies are presently analysing how best to develop an exit strategy from these measures and to determine how the epidemic may progress once measures are lifted. Mathematical models are currently providing short and long term forecasts regarding the future course of the COVID-19 outbreak in the UK to support evidence-based policymaking. We present a deterministic, age-structured transmission model that uses real-time data on confirmed cases requiring hospital care and mortality to provide up-to-date predictions on epidemic spread in ten regions of the UK. The model captures a range of age-dependent heterogeneities, reduced transmission from asymptomatic infections and produces a good fit to the key epidemic features over time. We simulated a suite of scenarios to assess the impact of differing approaches to relaxing social distancing measures from 7th May 2020 on the estimated number of patients requiring inpatient and critical care treatment, and deaths. With regard to future epidemic outcomes, we investigated the impact of reducing compliance, ongoing shielding of elder age groups, reapplying stringent social distancing measures using region based triggers and the role of asymptomatic transmission. We find that significant relaxation of social distancing measures from 7th May onwards can lead to a rapid resurgence of COVID-19 disease and the health system being quickly overwhelmed by a sizeable, second epidemic wave. In all considered age-shielding based strategies, we projected serious demand on critical care resources during the course of the pandemic. The reintroduction and release of strict measures on a regional basis, based on ICU bed occupancy, results in a long epidemic tail, until the second half of 2021, but ensures that the health service is protected by reintroducing social distancing measures for all individuals in a region when required. Our work confirms the effectiveness of stringent non-pharmaceutical measures in March 2020 to suppress the epidemic. It also provides strong evidence to support the need for a cautious, measured approach to relaxation of lockdown measures, to protect the most vulnerable members of society and support the health service through subduing demand on hospital beds, in particular bed occupancy in intensive care units.

Pneumococcal vaccine and serotype replacement in England: the bias of increased reporting

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
C Chiavenna ◽  
A Presanis ◽  
A Charlett ◽  
S Ladhani ◽  
D De Angelis
Keyword(s):  
Pneumococcal Vaccine ◽  
Pneumococcal Disease ◽  
Model Building ◽  
Age Groups ◽  
Statistical Modelling ◽  
Incidence Rates ◽  
Synthetic Control ◽  
Serotype Replacement ◽  
Vaccine Type ◽  
The Impact

Abstract Background Increased incidence of invasive pneumococcal disease (IPD) attributable to non-vaccine serotypes (NVT) has been reported in several countries following introduction of PCV7 and PCV13 vaccines, concurrently with a reduction in vaccine-type IPD. Such serotype replacement has, importantly, emerged in England, offsetting the benefit of PCV introduction. We scrutinise most recent findings to assess if the estimated increase in NVT disease might result from surveillance artefacts. Methods Using IPD surveillance for 2000-2018, we estimate the impact of PCV7 and PCV13 introduction on age-serotype-specific incidence rates through a synthetic control regression model, building counterfactuals by combining age-specific incidences reported for pathogens unaffected by PCVs. Results Following the introduction of PCV7 and PCV13 (pre-2006 vs post-2011), total IPD incidence declined by 57% and by 76% in children younger than 5. PCV7-IPD decreased by 93% in all age groups, whereas PCV13-IPD declined by 68% since PCV13 was introduced. Importantly, NVT-IPD increased by 43% after PCV7, with non-significant statistical increases in most age groups. Conclusions Through appropriate statistical modelling, we disentangled the impact of vaccine and improved surveillance on the changes in IPD incidence rates. By controlling for the confounding effects of improved surveillance, we are able to estimate a lower serotype replacement. Key messages Pneumococcal vaccine has been beneficial despite serotype replacement. Adequate statistical methods are needed to disentangle the two phenomena.

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