Measles Outbreak in Unvaccinated and Partially Vaccinated Children and Adults in the United States and Canada (2018-2019): A Narrative Review of Cases

Health system barriers to timely routine measles vaccinations in rural southwest China: a qualitative study on the perspectives of township vaccination professionals and village doctors

OBJECTIVES

A well-functioning health system ensures timely routine measles vaccinations for age-appropriate children, minimising measles risk. However, there is limited knowledge about the impact of the performance of immunisation programmes in health systems on the timeliness of measles vaccination. This study aimed to identify health system barriers to timely routine measles vaccination in rural southwest China, integrating the perspectives of township vaccination professionals and village doctors.

DESIGN, SETTING AND PARTICIPANTS

Qualitative study among township vaccination professionals and village doctors in rural Guangxi, southwest China.

METHODS

20 focus group discussions (FGDs) at township level and 120 in-depth interviews (IDIs) at village level, based on a four-theme framework. We used convenience sampling to recruit 60 township vaccination professionals and 120 village doctors in 2015. Instruments used were a semistructured questionnaire and interview outlines. We collected township and village-level data focusing on themes of health resources allocation, pattern of vaccination services, management and supervision of vaccination services, and perceptions of vaccination policy. The FGDs and IDIs were audio-recorded and transcribed. Braun and Clarke's thematic analysis approach was adopted to synthesise findings into meaningful subthemes, narrative text and illustrative quotations.

RESULTS

The health system barriers to timely routine vaccinations were explored across four themes. Barriers in the health resources allocation theme comprised (1) inadequacy of vaccination-related human resources (eg, lack of township vaccination professionals and lack of young village doctors), and (2) incompatible and non-identical information system of vaccination services across regions. Barriers in the pattern of vaccination services theme included inflexible vaccination services models, for example, routine vaccination services being offered monthly on fixed vaccination days, limited numbers of vaccination days per month, vaccination days being set on non-local market days, vaccination days being clustered into a specific period and absence of formal vaccination appointments. Ineffective economic incentive mechanism was identified as a barrier in the management and supervision of vaccination services theme. Low-degree participation of village doctors in routine vaccination services was identified as a barrier in the perceptions of vaccination policy theme.

CONCLUSIONS

We encourage policymakers and stakeholders to apply these findings to improve the timeliness of routine vaccination. Barriers to timely routine vaccination include inadequate allocation of vaccination-related resources and inflexible vaccination service delivery models. Financial and non-financial incentives should be used to retain and recruit vaccination professionals and village doctors. Strengthening information systems with unified data standards enables cross-regional data exchange. Optimising immunisation services and rationalising vaccination days could eliminate health system barriers and improve vaccination timeliness in rural China.

Measles: Contemporary considerations for the emergency physician

Measles, or rubeola, is a highly contagious acute febrile viral illness. Despite the availability of an effective vaccine since 1963, measles outbreaks continue worldwide. This article seeks to provide emergency physicians with the contemporary knowledge required to rapidly diagnose potential measles cases and bolster public health measures to reduce ongoing transmission.

Mapping the timeliness of routine childhood vaccination in The Gambia: A spatial modelling study

INTRODUCTION

Timeliness of routine vaccination shapes childhood infection risk and thus is an important public health metric. Estimates of indicators of the timeliness of vaccination are usually produced at the national or regional level, which may conceal epidemiologically relevant local heterogeneities and makeitdifficultto identify pockets of vulnerabilities that could benefit from targeted interventions. Here, we demonstrate the utility of geospatial modelling techniques in generating high-resolution maps of the prevalence of delayed childhood vaccination in The Gambia. To guide local immunisation policy and prioritize key interventions, we also identified the districts with a combination of high estimated prevalence and a significant population of affected infants.

METHODS

We used the birth dose of the hepatitis-B vaccine (HepB0), third-dose of the pentavalent vaccine (PENTA3), and the first dose of measles-containing vaccine (MCV1) as examples to map delayed vaccination nationally at a resolution of 1 × 1-km2 pixel. We utilized cluster-level childhood vaccination data from The Gambia 2019-20 Demographic and Health Survey. We adopted a fully Bayesian geostatistical model incorporating publicly available geospatial covariates to aid predictive accuracy. The model was implemented using the integrated nested Laplace approximation-stochastic partial differential equation (INLA-SPDE) approach.

RESULTS

We found significant subnational heterogeneity in delayed HepB0, PENTA3 and MCV1 vaccinations. Specificdistricts in the central and eastern regions of The Gambia consistentlyexhibited the highest prevalence of delayed vaccination, while the coastal districts showed alower prevalence forallthree vaccines. We also found that districts in the eastern, central, as well as in coastal parts of The Gambia had a combination of high estimated prevalence of delayed HepB0, PENTA3 and MCV1 and a significant population of affected infants.

CONCLUSIONS

Our approach provides decision-makers with a valuable tool to better understand local patterns of untimely childhood vaccination and identify districts where strengthening vaccine delivery systems could have the greatest impact.

Geographic disparities and predictors of vaccination exemptions in Florida: a retrospective study

BACKGROUND

In the United States, state-level policies requiring vaccination of school-going children constitute a critical strategy for improving vaccination coverage. However, policies allowing vaccination exemptions have also been implemented and contribute to reductions in vaccination coverage and potential increases in the burden of vaccine-preventable diseases. Understanding the geographic disparities in the distribution of vaccination exemptions and identifying high risk areas is necessary for guiding resource allocation and public health control strategies. This study investigated geographic disparities in vaccination exemptions as well as socioeconomic and demographic predictors of vaccination exemptions in Florida.

METHODS

Vaccination exemption data were obtained from the Florida Department of Health's Florida HealthCHARTS web interface. Spatial patterns in geographic distribution of total and non-medical vaccination exemptions were assessed using county-level choropleth maps. Negative binomial models were used to identify significant predictors of county-level risks of both total and non-medical vaccination exemptions.

RESULTS

Total exemptions varied from 0 to 30.2 per 10,000 people. Nine counties had exemption risks in the top two classes (10.4-15.9 and 15.9-30.2 exemptions per 10,000 people). These counties were distributed in five distinct areas: Western Panhandle, central northern area, central, South-eastern coastal area, and the southern coastal border of the state. Non-medical exemptions varied from 0 to 10.4 per 10,000 people. Fifteen counties had exemption risks in the top two classes (3.7-5.6 and 5.6-10.4 exemptions per 10,000 people), and were located in six distinct areas: Western and Central Panhandle, Northeastern, Central-eastern coastal area, Central-western coastal area, and the South-western coastal border of the state. Predictors of high risk of total vaccination exemptions were high density of primary care providers (p < 0.001), high median income (p = 0.001), high percentage of Hispanic population (p = 0.046), and low percentage of population with a college education (p = 0.013). A predictor of high risk of non-medical vaccination exemptions was high percentage of White population (p = 0.045). However, predictors of low risks of non-medical exemptions were high percentages of population: living in rural areas (p = 0.023), with college education (p = 0.013), with high school education (p = 0.009), and with less than high school education (p < 0.001).

CONCLUSIONS

There is evidence of county-level geographic disparities in both total and non-medical vaccination exemption risks in Florida. These disparities are explained by differences in county-level socioeconomic and demographic factors. Study findings are important in guiding resource allocation for health planning aimed at improving vaccination rates and reducing incidence of vaccine-preventable diseases.

Parents’ and Guardians’ Willingness to Vaccinate Their Children against COVID-19: A Systematic Review and Meta-Analysis

COVID-19 vaccination for children is crucial to achieve herd immunity. This is the first systematic review and meta-analysis to estimate parents’ and guardians’ willingness to vaccinate their children against COVID-19 and identify the determinants of vaccination intention. Systematic research was performed on the two databases (PubMed and EMBASE) from inception to 6 November 2021. Acceptance rates were pooled by use of a random-effects model and all predictors of vaccine acceptance were identified according to the health belief model (HBM) framework. This analysis was registered with PROSPERO (CRD42021292326) and reported in compliance with the PRISMA guidelines. Of 452 identified records, 29 eligible studies were included (N = 68,327 participants). The estimated worldwide vaccination acceptance rate was 61.40% (95% CI: 53.56–68.69%, I² = 99.3%), ranging from 21.6% to 91.4% across countries and regions. In the determinant assessment, the age of parents and guardians, access to scientific information and recommendations, routine and influenza vaccination behavior, and the willingness of parents and guardians to vaccinate themselves were potentially significant predictors of the vaccination willingness. Given the limited quality and quantity of included articles, future studies with a rigorous design will be necessary for the confirmation of our findings.

Epidemiology of measles cases, vaccine effectiveness, and performance towards measles elimination in The Gambia

Introduction

In 2011, member states of the World Health Organization (WHO) Africa Regional Office (AFRO) resolved to eliminate Measles by 2020. Our study aims to assess The Gambia’s progress towards the set AFRO measles elimination target and highlight surveillance and immunisation gaps to better inform future measles prevention strategies.

Material and methods

A retrospective review of measles surveillance data for the period 2011–2019, was extracted from The Gambia case-based measles surveillance database. WHO—UNICEF national coverage estimates were used for estimating national level MCV coverage. Measles post campaign coverage survey coverage estimates were used to estimate national measles campaign coverage.

Results

One hundred and twenty-five of the 863 reported suspected cases were laboratory confirmed as measles cases. More than half (53.6%) of the confirmed cases have unknown vaccination status, 24% of cases were vaccinated, 52.8% of cases occurred among males, and 72.8% cases were among urban residents. The incidence of measles cases per million population was lowest (0) in 2011–2012 and highest in 2015 and 2016 (31 and 23 respectively). The indicator for surveillance sensitivity was met in all years except in 2016 and 2019. Children aged 5–9 years (Incidence Rate Ratio—IRR = 0.6) and residents of Central River region (IRR = 0.21) had lower measles risk whilst unvaccinated (Adjusted IRR = 5.95) and those with unknown vaccination status (IRR 2.21) had higher measles risk. Vaccine effectiveness was 89.5%.

Conclusion

The Gambia’s quest to attain measles elimination status by 2020 has registered significant success but it is unlikely that all target indicators will be met. Vaccination has been very effective in preventing cases. There is variation in measles risk by health region, and it will be important to take it into account when designing prevention and control strategies. The quality of case investigations should be improved to enhance the quality of surveillance for decision making.

Genetic Characterizations and Molecular Evolution of the Measles Virus Genotype B3's Hemagglutinin (H) Gene in the Elimination Era

Measles virus (MeV) genotype B3 is one globally significant circulating genotype. Here, we present a systematic description of long-term evolutionary characterizations of the MeV genotype B3's hemagglutinin (H) gene in the elimination era. Our results show that the B3 H gene can be divided into two main sub-genotypes, and the highest intra-genotypic diversity was observed in 2004. MeV genotype B3's H gene diverged in 1976; its overall nucleotide substitution rate is estimated to be 5.697 × 10^-4 substitutions/site/year, and is slowing down. The amino acid substitution rate of genotype B3's H gene is also decreasing, and the mean effective population size has been in a downward trend since 2000. Selection pressure analysis only recognized a few sites under positive selection, and the number of positive selection sites is getting smaller. All of these observations may reveal that genotype B3's H gene is not under strong selection pressure, and is becoming increasingly conservative. MeV H-gene or whole-genome sequencing should be routine, so as to better elucidate the molecular epidemiology of MeV in the future.

Worldwide Vaccination Willingness for COVID-19: A Systematic Review and Meta-Analysis

Countries across the globe are currently experiencing a third or fourth wave of SARS-CoV-2 infections; therefore, the need for effective vaccination campaigns is higher than ever. However, effectiveness of these campaigns in disease reduction is highly dependent on vaccination uptake and coverage in susceptible populations. Therefore, this systematic review and meta-analysis estimated the vaccination intention and identified determinants of willingness and hesitancy. This study updates the existing body of literature on vaccination willingness, and was conducted according to the PRISMA guidelines. PubMed was searched for publications, selecting only studies published between 20 October 2020 and 1 March 2021, in English, with participants aged >16 years of age. The search identified 411 articles, of which 63 surveys were included that accounted for more than 30 countries worldwide. The global COVID-19 vaccination willingness was estimated at 66.01% [95% CI: 60.76–70.89% I² = 99.4% [99.3%; 99.4%]; τ² = 0.83]. The vaccination willingness varied within as well as between countries. Age, gender, education, attitudes and perceptions about vaccines were most frequently observed to be significantly associated with vaccine acceptance or refusal.

How To Prepare for the Unexpected: a Public Health Laboratory Response

Public health laboratories (PHLs) continue to face internal and external challenges to their abilities to provide successful, timely responses to public health crises and emerging threats. These laboratories are mandated to maintain the health of their communities by identifying, diagnosing, and warning constituents of potential and real health emergencies.

Public health laboratories (PHLs) continue to face internal and external challenges to their abilities to provide successful, timely responses to public health crises and emerging threats. These laboratories are mandated to maintain the health of their communities by identifying, diagnosing, and warning constituents of potential and real health emergencies. Due to the changing characteristics of public health threats and their cross-jurisdictional nature, laboratories are facing increased pressure to ensure that they respond in a consistent and coordinated manner. Here, the Association of Public Health Laboratories (APHL) Emerging Leader Program Cohort 11 members have compiled stories from subject matter experts (SMEs) at PHLs with direct involvement in crises to determine the characteristics of a successful response. Experts examined a diverse selection of emerging threats from across PHLs, including infectious diseases, opioids, natural disasters, and government shutdowns. While no public health crisis will be identical to another, overarching themes were consistent across subjects. Experiences from SMEs that could improve future responses to emerging threats are highlighted.

Air Passenger Travel and International Surveillance Data Predict Spatiotemporal Variation in Measles Importations to the United States

Measles incidence in the United States has grown dramatically, as vaccination rates are declining and transmission internationally is on the rise. Because imported cases are necessary drivers of outbreaks in non-endemic settings, predicting measles outbreaks in the US depends on predicting imported cases. To assess the predictability of imported measles cases, we performed a regression of imported measles cases in the US against an inflow variable that combines air travel data with international measles surveillance data. To understand the contribution of each data type to these predictions, we repeated the regression analysis with alternative versions of the inflow variable that replaced each data type with averaged values and with versions of the inflow variable that used modeled inputs. We assessed the performance of these regression models using correlation, coverage probability, and area under the curve statistics, including with resampling and cross-validation. Our regression model had good predictive ability with respect to the presence or absence of imported cases in a given state in a given year (area under the curve of the receiver operating characteristic curve (AUC) = 0.78) and the magnitude of imported cases (Pearson correlation = 0.84). By comparing alternative versions of the inflow variable averaging over different inputs, we found that both air travel data and international surveillance data contribute to the model's ability to predict numbers of imported cases and individually contribute to its ability to predict the presence or absence of imported cases. Predicted sources of imported measles cases varied considerably across years and US states, depending on which countries had high measles activity in a given year. Our results emphasize the importance of the relationship between global connectedness and the spread of measles. This study provides a framework for predicting and understanding imported case dynamics that could inform future studies and outbreak prevention efforts.

Human immunology and immunotherapy: main achievements and challenges

The immune system is a fascinating world of cells, soluble factors, interacting cells, and tissues, all of which are interconnected. The highly complex nature of the immune system makes it difficult to view it as a whole, but researchers are now trying to put all the pieces of the puzzle together to obtain a more complete picture. The development of new specialized equipment and immunological techniques, genetic approaches, animal models, and a long list of monoclonal antibodies, among many other factors, are improving our knowledge of this sophisticated system. The different types of cell subsets, soluble factors, membrane molecules, and cell functionalities are some aspects that we are starting to understand, together with their roles in health, aging, and illness. This knowledge is filling many of the gaps, and in some cases, it has led to changes in our previous assumptions; e.g., adaptive immune cells were previously thought to be unique memory cells until trained innate immunity was observed, and several innate immune cells with features similar to those of cytokine-secreting T cells have been discovered. Moreover, we have improved our knowledge not only regarding immune-mediated illnesses and how the immune system works and interacts with other systems and components (such as the microbiome) but also in terms of ways to manipulate this system through immunotherapy. The development of different types of immunotherapies, including vaccines (prophylactic and therapeutic), and the use of pathogens, monoclonal antibodies, recombinant proteins, cytokines, and cellular immunotherapies, are changing the way in which we approach many diseases, especially cancer.

MMR Vaccine Adverse Drug Reactions Reports in the CDC WONDER System, 1989-2019

Dissemination of misleading information regarding vaccine safety has contributed to the reduction in vaccination rates and the resurgence of diseases once considered eliminated. The CDC WONDER interface can be used to perform simple but powerful safety analyses and counter misinformation. The dissemination of false and misleading information regarding vaccine adverse reactions online has led to negative consequences, including raising parents' concerns about vaccine safety and fostering a growing opposition to the use of vaccines. However, health care workers can also use online resources to counter misinformation. The Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research (CDC WONDER) is an online interface that allows health care workers to access the large-linked electronic health record database Vaccine Adverse Event Reporting System and perform near real-time vaccine safety analyses; hence it has the potential to become a powerful and accessible tool to provide information-driven decision-making regarding vaccine safety.