scholarly journals The effect of opinion clustering on disease outbreaks

2008 ◽  
Vol 5 (29) ◽  
pp. 1505-1508 ◽  
Author(s):  
Marcel Salathé ◽  
Sebastian Bonhoeffer
Keyword(s):  
Vaccination Coverage ◽  
Belief Systems ◽  
Herd Immunity ◽  
Disease Outbreaks ◽  
Disease Outbreak ◽  
High Income ◽  
Opinion Formation ◽  
Vaccine Preventable Diseases ◽  
Vaccination Rates ◽  
High Level

Many high-income countries currently experience large outbreaks of vaccine-preventable diseases such as measles despite the availability of highly effective vaccines. This phenomenon lacks an explanation in countries where vaccination rates are rising on an already high level. Here, we build on the growing evidence that belief systems, rather than access to vaccines, are the primary barrier to vaccination in high-income countries, and show how a simple opinion formation process can lead to clusters of unvaccinated individuals, leading to a dramatic increase in disease outbreak probability. In particular, the effect of clustering on outbreak probabilities is strongest when the vaccination coverage is close to the level required to provide herd immunity under the assumption of random mixing. Our results based on computer simulations suggest that the current estimates of vaccination coverage necessary to avoid outbreaks of vaccine-preventable diseases might be too low.

scholarly journals Getting personal: how vaccination exemptions shape herd immunity

2018 ◽  
Author(s):  
Emma R Nedell ◽  
Romain Garnier ◽  
Saad B Omer ◽  
Shweta Bansal
Keyword(s):  
Policy Change ◽  
Spatial Clustering ◽  
Vaccine Coverage ◽  
Herd Immunity ◽  
The United States ◽  
Vaccine Preventable Diseases ◽  
Vaccination Rates ◽  
Before And After ◽  
Exemption Policy ◽  
Epidemiological Effects

Background: State-mandated school entry immunization requirements in the United States play an important role in achieving high vaccine coverage and preventing outbreaks of vaccine-preventable diseases. Most states allow non-medical exemptions that let children remain unvaccinated on the basis of personal beliefs. However, the ease of obtaining such exemptions varies, resulting in a patchwork of state vaccination exemption laws, contributing to heterogeneity in vaccine coverage across the country. In this study, we evaluate epidemiological effects and spatial variations in non-medical exemption rates in the context of vaccine policies. Methods and Findings: We first analyzed the correlation between non-medical exemption rates and vaccine coverage for three significant childhood vaccinations and found that higher rates of non-medical exemptions were associated with lower vaccination rates of school-aged children in all cases. We then identified a subset of states where exemption policy has recently changed and found that the effects on statewide non-medical exemption rates varied widely. Focusing further on Vermont and California, we illustrated how the decrease in non-medical exemptions due to policy change was concurrent to an increase in medical exemptions (in CA) or religious exemptions (in VT). Finally, a spatial clustering analysis was performed for Connecticut, Illinois, and California, identifying clusters of high non-medical exemption rates in these states before and after a policy change occurred. The clustering analyses show that policy changes affect spatial distribution of non-medical exemptions within a state. Conclusions: Our work suggests that vaccination policies have significant impacts on patterns of herd immunity. Our findings can be used to develop evidence-based vaccine legislation.

scholarly journals Status of Vaccine Coverage In Venezuelan Children, A Country With A Complex Humanitarian Crisis

2020 ◽  
Author(s):  
Tatiana Drummond ◽  
Isabel Marín ◽  
Anny Sánchez ◽  
Marianjosé Reyes ◽  
Jenny García ◽  
...  
Keyword(s):  
Vaccination Coverage ◽  
Vaccine Coverage ◽  
Immunization Coverage ◽  
Cross Sectional Study ◽  
Vaccination Schedule ◽  
Humanitarian Crisis ◽  
Cross Sectional ◽  
Vaccine Preventable Diseases ◽  
Vaccination Rates ◽  
One Year

Abstract In Venezuela, PAHO has reported an increase in vaccine-preventable diseases since 2016. The goal of this work was to assess vaccination coverage in children hospitalized in the Department of Pediatrics at the Hospital Universitario de Caracas (HUC). Methods: A descriptive cross-sectional study included 0 to 12 years old children hospitalized in HUC admitted between January 2015 and December 2019, and verified immunization scheme. The patient data were compared with the schedule of the Ministry of Health of Venezuela and analyzed by comparing immunization coverage by year of patient hospitalization and patient age. Results: A total of 2903 patients were surveyed, corresponding to 53.2% male, 37.4% infants. A coverage level above 95% was found only for BCG. Comparing vaccination coverage with the vaccination schedule vs year of patient hospitalization, it was observed a mean decrease in vaccine coverage of 21.5% in 2019 relative to 2015 (p = 0.0000). Vaccination rates in children under one year old were lower than in children older than 6 years for all vaccines (p = 0.0000) Conclusions: There is a decline in vaccination coverage in 2019 in relation to previous years, being the most affected children less than one year old

scholarly journals Childhood vaccination as a part of the National Immunization Schedule during the COVID-19: problems and potential solutions

2021 ◽  
Vol 4 (1) ◽  
pp. 85-89
Author(s):  
A.A. Girina ◽  
◽  
A.L. Zaplatnikov ◽  
F.I. Petrovskiy ◽  
L.P. Tandalova ◽  
...  
Keyword(s):  
Whooping Cough ◽  
Herd Immunity ◽  
Childhood Vaccination ◽  
Immunization Schedule ◽  
Vaccine Preventable Diseases ◽  
National Immunization ◽  
Fold Reduction ◽  
High Level ◽  
In The Beginning ◽  
And Child Health

Aim: to compare monthly implementation of immunization plan as a part of the National Immunization Schedule in 2019 and 2020 in children aged 0–18 years. Patients and Methods: monthly and annual form No. 5 “Information on prophylactic immunization” (from January 2019 to December 2020) was analyzed. Monthly implementation of immunization plan for each vaccine-preventable disease (whooping cough, poliomyelitis, mumps, rubella, measles, diphtheria tetanus and other) were analyzed separately. Results: in the beginning of the COVID-19 pandemic, a significant (8.8-fold) reduction in the coverage of children with immunization against vaccine-preventable diseases was reported compared to 2019 (р<0.0001). The reduction in the implementation of immunization schedule required urgent solutions to maintain a high level of herd immunity. The recovery of the required implementation of immunization plan against whooping cough and poliomyelitis was achieved by the end of 2020. The recovery of the required implementation of immunization plan against diphtheria and tetanus, measles, rubella, and mumps will be achieved in September 2020 (considering the National Immunization Schedule that includes revaccinations in preschool and school years). Conclusions: timely identification of the drawbacks of the organization of immunization and the prompt development of effective measures and implementation into clinical practice allowed for full implementation of immunization plan in children in 2020, despite the ongoing COVID-19 pandemic. KEYWORDS: vaccination, children, National Immunization Schedule, revaccination, COVID-19 pandemic. FOR CITATION: Girina A.A., Zaplatnikov A.L., Petrovskiy F.I., Tandalova L.P. Childhood vaccination as a part of the National Immunization Schedule during the COVID-19: problems and potential solutions. Russian Journal of Woman and Child Health. 2021;4(1):85–89. DOI: 10.32364/2618-8430-2021-4-1-85-89.

scholarly journals Public health practitioner perspectives on dealing with measles outbreaks if high anti-vaccination sentiment is present

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Penelope Robinson ◽  
Kerrie Wiley ◽  
Chris Degeling
Keyword(s):  
Public Health ◽  
Vaccination Schedule ◽  
Health Practitioner ◽  
Vaccine Preventable Diseases ◽  
Vaccination Rates ◽  
Modified Delphi ◽  
Global Pandemic ◽  
Measles Outbreak ◽  
High Level ◽  
Measles Outbreaks

Abstract Background Communities with low vaccination rates are at greater risk during outbreaks of vaccine preventable diseases. Most Australian parents support vaccines, but some refuse and are often judged harshly by their community, especially during an outbreak. We sought the perspectives of Australian public health experts on the key issues faced when managing a measles outbreak in an area with high anti-vaccination sentiment. Methods A measles outbreak scenario formed the basis of a 3-round modified Delphi process to identify key practitioner concerns in relation to parents/carers who don’t follow the recommended vaccination schedule. We surveyed a range of professionals in the field: policymakers, infectious disease experts, immunisation program staff, and others involved in delivering childhood vaccinations, to identify key priorities when responding to an outbreak in a community with low vaccination coverage. Results Findings indicate that responses to measles outbreaks in communities with high anti-vaccination sentiment are motivated by concerns about the potential for a much larger outbreak event. The highest operational priority is to isolate infected children. The two most highly ranked practical issues are mistrust from non-vaccinating members of the local region and combatting misinformation about vaccines. Trying to change minds of such individuals is not a priority during an outbreak, nor is vaccinating their children. Using media and social media to provide information about the outbreak and measures the public can take to limit the spread of the disease was a focus. Conclusions Our findings provide a deeper understanding of the challenges faced during an outbreak and priorities for communicating with communities where there is a high level of anti-vaccination sentiment. In the context of a global pandemic, the results of this study also have implications for managing public health responses to community transmission of SARS-CoV-2, as COVID-19 vaccines becomes widely available.

scholarly journals Influence of heterogeneous age-group contact patterns on critical vaccination rates for herd immunity to SARS-CoV-2

2021 ◽  
Author(s):  
Joan Saldana ◽  
Caterina M Scoglio
Keyword(s):  
Vaccination Coverage ◽  
Herd Immunity ◽  
Age Groups ◽  
Social Contact ◽  
Vaccination Strategy ◽  
Primary Concern ◽  
Vaccination Rates ◽  
Contact Patterns ◽  
Group Contact ◽  
Age Structured

Currently, several western countries have more than half of their population fully vaccinated against COVID-19. At the same time, some of them are experiencing a fourth or even a fifth wave of cases, most of them concentrated in sectors of the populations whose vaccination coverage is lower than the average. So, the initial scenario of vaccine prioritization has given way to a new one where achieving herd immunity is the primary concern. Using an age-structured vaccination model with waning immunity, we show that, under a limited supply of vaccines, a vaccination strategy based on minimizing the basic reproduction number allows for the deployment of a number of vaccine doses lower than the one required for maximizing the vaccination coverage. Such minimization is achieved by giving greater protection to those age groups that, for a given social contact pattern, have smaller fractions of susceptible individuals at the endemic equilibrium without vaccination, that is, to those groups that are more vulnerable to infection.

scholarly journals Protection to Six Vaccinable Pathogens in Paired Plasma/DBS and HIV Impact in Infected and Uninfected Children From Kinshasa

2021 ◽  
Author(s):  
Rodríguez-Galet Ana ◽  
Rubio-Garrido Marina ◽  
Valadés-Alcaraz Ana ◽  
Rodríguez-Domínguez Mario ◽  
Galán Juan Carlos ◽  
...  
Keyword(s):  
Vaccination Coverage ◽  
Test Performance ◽  
Herd Immunity ◽  
Roc Curves ◽  
Paediatric Population ◽  
Vaccine Preventable Diseases ◽  
Resource Limited ◽  
Republic Of The Congo ◽  
Coverage Rates ◽  
The Impact

Abstract Child vaccination reduces infant mortality rates. HIV-infected children present higher risk of diseases than non-infected. We report the protection coverage rates to 6 vaccine-preventable diseases in a paediatric population from the Democratic Republic of the Congo (DRC) and the impact of HIV infection, providing the first data on the validity of dried blood samples (DBS) to monitor the immune protection. During 2016-2018 DBS from 143 children/adolescents were collected in Kinshasa (DRC), being 52 HIV-infected. Forty-two had a paired plasma sample. Protective IgG was quantified (VirClia®IgG,Vircell) to obtain the optimal cut-off in IgG detection in DBS. ROC curves were generated with R software and statistical analyses with Stata. Protective IgG levels varied across pathogens, not reaching the herd immunity. HIV-infected presented lower vaccine protection than uninfected for all analysed pathogens, except rubella, with statistically significant differences for measles (30.8% vs. 53.8%;p=0.008) and tetanus (3.8% vs. 22%;p=0.004). New cut-offs were calculated when using DBS to improve test performance. We reinforce the necessity to increase pediatric vaccination coverage in Kinshasa, specially in HIV seropositive, with less capacity to maintain adequate antibody levels. DBS were useful to monitor vaccination coverage in seroprevalence studies in resource-limited settings, after optimizing the cut-off value for each pathogen.

scholarly journals Public Health Practitioner Perspectives on Dealing with Measles Outbreaks in Areas with high Anti-vaccination Sentiment

2020 ◽  
Author(s):  
Penelope Robinson ◽  
Kerrie Wiley ◽  
Chris Degeling
Keyword(s):  
Public Health ◽  
Vaccination Schedule ◽  
Effective Vaccine ◽  
Health Practitioner ◽  
Vaccine Preventable Diseases ◽  
Vaccination Rates ◽  
Modified Delphi ◽  
Measles Outbreak ◽  
High Level ◽  
Measles Outbreaks

Abstract BackgroundCommunities with low vaccination rates are at greater risk during outbreaks of vaccine preventable diseases. Most Australian parents support vaccines, but some refuse and are often judged harshly by their community, especially during an outbreak. We sought the perspectives of Australian public health experts on the key issues faced when managing a measles outbreak in an area with high anti-vaccination sentiment.MethodsA measles outbreak scenario formed the basis of a 3-round modified Delphi process to identify key practitioner concerns in relation to parents/carers who don’t follow the recommended vaccination schedule. We surveyed a range of professionals in the field: policymakers, infectious disease experts, immunisation program staff, and others involved in delivering childhood vaccinations, to identify key priorities when responding to an outbreak in a community with low vaccination coverage.ResultsFindings indicate that responses to measles outbreaks in communities with high anti-vaccination sentiment are motivated by concerns about the potential for a much larger outbreak event. The highest operational priority is to isolate infected children. The two most highly ranked practical issues are mistrust from non-vaccinating members of the local region and combatting misinformation about vaccines. Trying to change minds of such individuals is not a priority during an outbreak, nor is vaccinating their children. Using media and social media to provide information about the outbreak and measures the public can take to limit the spread of the disease was a focus.ConclusionsOur findings provide a deeper understanding of the challenges faced during an outbreak and priorities for communicating with communities where there is a high level of anti-vaccination sentiment. In the context of a global pandemic, the results of this study also have implications for managing public health responses to community transmission of SARS-CoV-2, if and when a safe and effective vaccine becomes widely available.

scholarly journals Steep decline of HPV 6 and genital warts despite low HPV vaccination coverage in young women in Germany: a long-term, population-based cohort study

2019 ◽  
Author(s):  
Agnieszka Denecke ◽  
Thomas Iftner ◽  
Angelika Iftner ◽  
Sebastian Riedle ◽  
Marion Ocak ◽  
...  
Keyword(s):  
Protective Effect ◽  
Young Women ◽  
Vaccination Coverage ◽  
Hpv Vaccination ◽  
Herd Immunity ◽  
Life Time ◽  
Genital Warts ◽  
Quadrivalent Vaccine ◽  
Vaccination Rates

Abstract Background: The introduction of human papilloma virus (HPV) vaccination has resulted in a remarkable decline of genital warts in women and men, but in Germany historical rates of vaccination are relatively low. We report long-term surveillance data on changes in HPV 6 and 11 infection and the prevalence of genital warts in young women in the Wolfsburg HPV epidemiological study (WOLVES).Methods: Women born in 1983/84, 1988/89, and 1993/94 participated in four cohorts between 2009/10 and 2014/15. Vaccination coverage and prevalence of HPV 6/11 and genital warts are reported for participants aged 19−22 years and 24−27 years at the time of analysis. Statistical analyses were done to compare similarly aged participants using 2 x 2 contingency tables (Röhmel-Mansmann unconditional exact test; two-side alpha of 0.05).Results: A total of 2,456 women were recruited. In 2010, vaccination rates were 40/659 (6.1%) in women aged 24−27 years and 142/600 (23.7%) in those aged 19−22 years; 5 years later, vaccination rates had increased to 135/733 (18.4%) and 177/368 (48.1%), respectively. Between 2010 and 2015, there was a statistically significant decrease in the prevalence of HPV 6 among women aged 24−27 years (2.12% versus 0%; P<0.0001) and women aged 19−22 years (2.0% versus 0%; P=0.0056). In total, 52 of 2341 participants were diagnosed with genital warts. There was a statistically significant decrease in the life-time risk of developing genital warts in women aged 24−27 years between 2010 and 2015 (4.7% versus 1.68%, respectively; P=0.0018). The overall life-time risk of developing genital warts in women aged 19−27 years decreased from 3.1% in 2010 to 1.2% in 2015 (P=0.0022).Conclusions: An increase in vaccination coverage was associated with a decreased prevalence of genital warts in young women. A protective effect greater than herd immunity alone was seen despite low vaccination rates. Quadrivalent vaccine had a protective effect on genital HPV 6 positivity and a fully protective effect on the development of genital warts in the youngest population.

scholarly journals Vaccination knowledge, attitudes and practices in patients with HIV: a cross-sectional survey

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
S Rousset ◽  
G Voglino ◽  
E Boietti ◽  
A Corradi ◽  
M R Gualano ◽  
...  
Keyword(s):  
Public Health ◽  
Infectious Diseases ◽  
Health System ◽  
Vaccination Coverage ◽  
Public Health System ◽  
Cross Sectional Survey ◽  
Hiv Patients ◽  
Cross Sectional ◽  
Contagion Risk ◽  
High Level

Abstract Background Infectious diseases are more common and severe in patients with HIV, which show different response to vaccines and a diminished protection. It is therefore very important to assess knowledge and attitudes towards vaccination in people with HIV, since precise vaccination coverage and vaccine hesitancy are not well established in this subgroup of patients. Methods A sample of 119 patients with HIV completed a cross-sectional survey. Patients were recruited during their routine medical examination at the infectious diseases clinic in Turin. The survey explored these main areas: demographics and history of HIV infection, vaccination history, attitudes towards vaccination, confidence in the public health system, contagion risk and disease seriousness perception. In this preliminary phase descriptive analysis were conducted. Results Preliminary data show that mean age of the participants was 49.51 years, 80% were males. The median of HIV infection duration was 10 years, while the median of the lymphocyte count was 762.50 cells/mm3. The disease with the highest vaccination coverage was tetanus (88.7%), considered a serious or very serious disease by 85.6% of the participants, despite low or very low contagion risk perception (84.1%). The disease with the lowest vaccination coverage was Herpes Zoster (7.3%), despite high or very high seriousness perception (70%). Furthermore, 99.1% of the participants showed high or very high confidence toward public health system professionals, and the majority of them (59.5%) stated that vaccines are more useful for the community than for the single person. Conclusions Vaccination coverage is still not fully satisfactory regarding diseases considered infrequent or mild. Considering the high level of confidence toward the public health system that has emerged, it is necessary to implement informative and operative strategies about vaccination for European HIV patients, which are particularly at risk regarding infectious diseases. Key messages Vaccination coverage and risk perception in HIV patients is not satisfactory for many diseases and an effort to implement informative strategies in Europe is needed. The role of vaccination in preventing infectious diseases in HIV patients should be recognized and strengthened by relying on the high level of confidence toward European public health systems.

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.

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