Vaccination Coverage In Population Research Articles

RHDV2 outbreak reduces survival and juvenile recruitment, causing European rabbit population collapse

AbstractInfectious diseases can cause considerable mortality in vertebrate populations, especially when a new pathogen emerges. Quantifying the impact of diseases on wild populations and dissecting the underlying mechanisms requires longitudinal individual monitoring combining demographic and epidemiologic data. Such longitudinal population studies are rare. Rabbit hemorrhagic disease (RHD) is one of the main causes of the decline in European wild rabbit (Oryctolagus cuniculus) populations. A new genotype of RHD virus (RHDV), called RHDV2 or GI.2, emerged in 2010, posing a new threat to previously weakened populations, particularly as this virus can infect individuals already immune to classical RHDV strains. Taking advantage of intensive monitoring from 2009 to 2014 by physical captures and microchip detections of a semi‐captive population of rabbits, we finely assessed the demographic impact of an initial RHDV2 outbreak that occurred in the population and identified the most affected demographic parameters. A multi‐event modeling analysis revealed decreased survival in both juveniles and adults in 2011 and 2012, suggesting an RHDV2 outbreak for two consecutive years. The short‐term survival benefit of vaccination against classical RHDV strains only during these years, and the recovery of carcasses with RHDV2 detection, supported this hypothesis. Variations in population vaccination coverage also explain the difference in adult survival between the two years of the outbreak. And the transient protective effect of vaccination could explain the prolonged duration of the outbreak. A brief episode of myxomatosis in 2011 seems to have had only a limited impact on the population. During outbreak years, in individuals not recently vaccinated, monthly juvenile survival crashed (0.55), and annual adult survival was three times lower than in normal years (0.21 vs. 0.69). The combination of successive juvenile and adult survival estimates for unvaccinated rabbits during the outbreak years resulted in a very low recruitment rate in the breeding population. Finally, RHDV2 outbreaks appear to have caused mortalities comparable to those caused by older classical RHDV strains and may have a strong demographic impact on wild populations of European rabbit. This work highlights the importance of long‐term observational and experimental studies to better understand the impact of epidemics on animal populations.

The dawn of a cure for sickle cell disease through CRISPR-based treatment: A critical test of equity in public health genomics.

Equity in access to genomic technologies, resources, and products remains a great challenge. This was evident especially during the coronavirus disease 2019 (COVID-19) pandemic when the majority of lower middle-income countries were unable to achieve at least 10% population vaccination coverage during initial COVID-19 vaccine rollouts, despite the rapid development of those vaccines. Sickle cell disease (SCD) is an inherited monogenic red blood cell disorder that affects hemoglobin, the protein that carries oxygen through the body. Globally, the African continent carries the highest burden of SCD with at least 240,000 children born each year with the disease. SCD has evolved from a treatable to a curable disease. Recently, the UK medical regulator approved its cure through clustered regularly interspaced short palindromic repeat (CRISPR)-based treatment, whereas the US Food and Drug Administration has equally approved two SCD gene therapies. This presents a remarkable opportunity to demonstrate equity in public health genomics. This CRISPR-based treatment is expensive and therefore, a need for an ambitious action to ensure that they are affordable and accessible where they are needed most and stand to save millions of lives.

Differences between Italians and immigrants in COVID-19 vaccination coverage in the Reggio Emilia resident population (Emilia-Romagna Region, Northern Italy)

The present work describes the cumulative coverage curves by country of birth, sex, age, and area of residence of the adult population residing in the province of Reggio Emilia (Emilia-Romagna Region, Northern Italy).The analyses are stratified by country of birth into HDC (Highly Developed Country), mostly Italians, and HMPC (Highly Migration Pressure Country), as a proxy of migrant status, excluding deaths. Vaccinations carried out up to September 2022 and recorded in the information system were considered, including vaccinations performed outside the province. Vaccinations done abroad are not included when the information is incomplete or the type of vaccine is different from those administered in Italy.Vaccination coverage (%) by number of doses and estimated Hazard Ratio (HR) and related 95% confidence intervals (95%CI) are calculated using Cox models, adjusted for age and stratified by sex.A lower vaccination coverage was detected, delayed by a few weeks, among HMPC, but the differences in vaccination coverage are reversed when the different age structure of the two populations is taken into account. From the estimates of the Cox models, a higher propensity to vaccinate was noted among immigrants, in particular among women (women HR: 1.65; CI95% 1.52-1.78; men HR: 1.39; CI95% 1.28-1.52). Women were vaccinated first, but, at the end of the observation period, there were no particular differences in coverage between the two sexes, either among Italians or immigrants. Focusing on the area of origin, a strong propensity for vaccination was noted, particularly among who came from North Africa. In the mountain areas of the province, a lower propensity for vaccination was observed, perhaps explained by the greater distance of the vaccination centers or by a lower acceptability of the vaccine.

Routine Vaccination Coverage in an Adolescent Transgender Population in a Large Tertiary Care Center in the United States

To address healthcare disparities among transgender and gender diverse (TGD) adolescents, we examined vaccination coverage in those receiving gender-affirming care. Our study analyzed de-identified data (2013-2022) from a tertiary care clinic. Comparing vaccination rates of 203 TGD adolescent patients to age-matched peers in New York State using CDC National Immunization Survey-Teen data. We found TGD patients had similar vaccination coverage to the general adolescent population. Notably, TGD patients had significantly higher up-to-date human papillomavirus vaccination coverage (76.4%, CI=69.9, 82.0) than the NYS adolescent population (60.5%, CI=53.0, 67.5). This suggests TGD adolescents at gender-affirming clinics maintain or exceed vaccination rates of their cisgender counterparts. Future research should explore vaccination rates for TGD individuals without access to gender-affirming care.

Hospitalisations and Deaths Averted by COVID-19 Vaccination in Navarre, Spain, 2021-2022.

In 2021-2022, most of the Spanish population received COVID-19 vaccines and a high proportion of them had SARS-CoV-2 infection. We estimated the rate of hospitalisations and deaths that were averted by risk reduction among vaccinated COVID-19 cases. Hospitalisations and deaths were analysed among COVID-19 cases confirmed in 2021 and 2022 in Navarre, Spain. To calculate the number of prevented outcomes by sex, age, comorbidities, and semester, the difference in the risk of each outcome between unvaccinated and vaccinated cases was multiplied by the number of vaccinated cases. COVID-19 vaccination coverage with any dose reached 88%, 86% with full vaccination, and 56% with a booster dose. The cumulative rates per 1000 inhabitants were 382 COVID-19 confirmed cases, 6.70 hospitalisations, and 1.15 deaths from COVID-19. The estimated rates of prevented events by vaccination were 16.33 hospitalisations and 3.39 deaths per 1000 inhabitants, which was 70.9% and 74.7% of expected events without vaccination, respectively. People aged 80 years and older or with major chronic conditions accounted for the majority of hospitalizations and deaths prevented by COVID-19 vaccination. One hospitalisation and death due to COVID-19 were averted for every 53 and 258 people vaccinated, respectively. The high COVID-19 vaccine effect in reducing the risk of severe outcomes and the high vaccination coverage in risk populations prevented three out of four hospitalisations and deaths due to COVID-19 during a period of intense circulation of SARS-CoV-2.

Early COVID-19 vaccine effectiveness of XBB.1.5 vaccine against hospitalisation and admission to intensive care, the Netherlands, 9 October to 5 December 2023.

We present early vaccine effectiveness (VE) estimates of the 2023 seasonal COVID-19 XBB.1.5 vaccine against COVID-19 hospitalisation and admission to an intensive care unit (ICU) in previously vaccinated adults ≥ 60 years in the Netherlands. We compared vaccination status of 2,050 hospitalisations including 92 ICU admissions with age group-, sex-, region- and date-specific population vaccination coverage between 9 October and 5 December 2023. VE against hospitalisation was 70.7% (95% CI: 66.6-74.3), VE against ICU admission was 73.3% (95% CI: 42.2-87.6).

Possible counter-intuitive impact of local vaccine mandates for vaccine-preventable infectious diseases.

We modeled the impact of local vaccine mandates on the spread of vaccine-preventable infectious diseases, which in the absence of vaccines will mainly affect children. Examples of such diseases are measles, rubella, mumps, and pertussis. To model the spread of the pathogen, we used a stochastic SIR (susceptible, infectious, recovered) model with two levels of mixing in a closed population, often referred to as the household model. In this model, individuals make local contacts within a specific small subgroup of the population (e.g., within a household or a school class), while they also make global contacts with random people in the population at a much lower rate than the rate of local contacts. We considered what would happen if schools were given freedom to impose vaccine mandates on all of their pupils, except for the pupils that were exempt from vaccination because of medical reasons. We investigated first how such a mandate affected the probability of an outbreak of a disease. Furthermore, we focused on the probability that a pupil that was medically exempt from vaccination, would get infected during an outbreak. We showed that if the population vaccine coverage was close to the herd-immunity level, then both probabilities may increase if local vaccine mandates were implemented. This was caused by unvaccinated pupils possibly being moved to schools without mandates.

COVID-19 Vaccine for Children: Determinants and Beliefs Contributing to Vaccination Decision of Parents in Germany 2021/2022.

To reduce the number of COVID-19 cases, vaccines were rapidly made available worldwide. For a strategically targeted response to the COVID-19 pandemic, population vaccination coverage was to be maximized. The target groups also included healthy children. In this context, it is important to understand the determinants and beliefs that lead parents to favor or oppose COVID-19 immunization in children. This study aimed to investigate parents' COVID-19 vaccination willingness in Germany for children aged 5-11 years in 2021/2022. For this purpose, the determinants and beliefs behind parents' vaccination decisions were examined. Descriptive analysis and bivariate correlations were performed on COVID-19 vaccination willingness and parents' mental health status, general vaccination attitudes, and SARS-CoV-2 politics perceptions. In total, 2401 participants fully participated in this cross-sectional study. The COVID-19 vaccination uptake (71.4%) outweighed the vaccination refusal (19.4%). Correlations revealed higher vaccine acceptance in parents presenting full vaccination certificates (90.9%), COVID-19 immunizations (99.9%), or increased COVID-19 fear (93.6%). Vaccination-refusal was associated with higher perceived pressure by COVID-19 vaccination campaigns (87.7%), higher experienced restrictions due to COVID-19 protective measures in parents' social environment (83.6%), and engagement against COVID-19 protective measures (51.6%). Besides general anxiety, no significant correlations were observed between parents' mental health variables and vaccination willingness. Although several factors are ultimately associated with vaccination willingness, future vaccination campaigns should prioritize reducing pressure, increasing trust, and considering parents' differentiation between familiar and unfamiliar pathogens during their vaccination decision-making process.

Tracing the adaptive evolution of SARS-CoV-2 during vaccine roll-out in Norway.

Vaccination against SARS-CoV-2 has greatly mitigated the impact of the COVID-19 pandemic. However, concerns have been raised about the degree to which vaccination might drive the emergence and selection of immune escape mutations that will hamper the efficacy of the vaccines. In this study, we investigate whether vaccination impacted the micro-scale adaptive evolution of SARS-CoV-2 in the Oslo region of Norway, during the first nine months of 2021, a period in which the population went from near-zero to almost 90 per cent vaccine coverage in the population over 50 years old. Weekly aggregated data stratified by age on vaccine uptake and number of SARS-CoV-2 cases in the area were obtained from the National Immunization Registry and the Norwegian Surveillance System for Communicable Diseases, respectively. A total of 6,438 virus sequences (7.5 per cent of the registered cases) along with metadata were available. We used a causal-driven approach to investigate the relationship between vaccination progress and changes in the frequency of 362 mutations present in at least ten samples, conditioned on the emergence of new lineages, time, and population vaccination coverage. After validating our approach, we identified 21 positive and 12 negative connections between vaccination progress and mutation prevalence, and most of them were outside the Spike protein. We observed a tendency for the mutations that we identified as positively connected with vaccination to decrease as the vaccinated population increased. After modelling the fitness of different competing mutations in a population, we found that our observations could be explained by a clonal interference phenomenon in which high fitness mutations would be outcompeted by the emergence or introduction of other high-fitness mutations.

COVID 19 VACCINATION COVERAGE AND ITS ADVERSE EVENTS AMONG GENERAL POPULATION OF CENTRAL INDIA- A CROSS SECTIONAL STUDY

Background: The ongoing pandemic of Corona virus disease 2019(covid-19) is caused by Severe acute respiratory syndrome Corona virus 2(SARCOV-2). The World Health Organization declared it as public health emergency of international concern on January 2020, and later declared as pandemic on 11 March 2020. Indian population are less aware of the pandemic and have less access to health care facilities. Vaccinating these populations can decrease disease burden and control the on-going pandemic. Aim and Objectives: To study AEFI pattern following COVID- 19 vaccination in populations of central India. To estimate the COVID 19 vaccination coverage in general populations of central India. To assess the factorsresponsible for COVID 19 vaccination coverage. Material and Methods: Acommunity based crosssectionalstudy will be conducted among 350 participantsresiding in the eld practice area of Urban and Rural Health care Training Centre of tertiary medical college of Nagpur from January 2022 to February 2022. Data is collected using structured interview questionnaire after obtaining informed consent. Data is entered in Excelsheet and SPSS 20 for analysis. Analysis will be done using Chi square test and a p Value of <0.05 will be taken as signicant. Results: In the present study, 84.31% (301 out of 357) of the study participants had taken COVID Vaccine, of which 217 (60.78%) were partially vaccinated and remaining 80 (23.52%)were fullyVaccinated.Most ofthe vaccinated study participants had takenCovishield vaccine 237 (78.73%)followed byCovaxin vaccine 62 (20.59%). And 16.52% were aware about AE reporting however those who aware of them 20% report Adverse events. The percentage of The AEFI st nd experienced after 1 dose was 112 (51.61%) and 2 dose was 30 (35.71%). Fever and general fatigue were the most common AEFI experienced. Conclusion: The COVID vaccine coverage was good in general population.Although adverse events due to vaccines were reported during the survey none of the eventsreported were severe orserious, which reiteratesthat the vaccines used in India are safe and the events will last without any kind of sequelae.Studies ofthis nature reinforce theneedfor vigilant monitoring and reporting of AEFIs

A Systematic Review of Yellow Fever Outbreaks and Public Health Responses in Nigeria.

Yellow fever (YF) outbreaks continue to occur in Nigeria with a high mortality rate despite a well-established mode of transmission and the availability of a potent vaccine. This review is aimed at describing the epidemiology, determinants, and public health responses of yellow fever outbreaks in Nigeria from 1864 to 2020. The guidelines for the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) were used to conduct the review from November 2020 to April 2021. PubMed database, WHO library databases, and Google Scholar were used to search for relevant published materials including original and reviewed articles, conference papers and case reports from 1864 to 2020. Forty - eight articles and reports were included in the final reviews. Twenty - three outbreaks were described involving 33,830 suspected, presumptive, or confirmed cases of yellow fever and 8,355 deaths. The outbreaks occurred in every state of Nigeria including the Federal Capital Territory mostly during the rainy season. Low immunity in the population or low vaccination coverage, poor vector control, rainforest or savanna vegetation, rural-urban migration, and imported virus by travelers were common determinants noted. Public health responses have been through, centrally coordinated laboratory support, case management, emergency immunization, vector control, and surveillance. Yellow fever outbreaks have increased in frequency and geographical spread with associated mortality rates. To stem the tide, mass immunization with 17D vaccines is encouraged, planned urbanization with adequate vector control measures enforced, effective case definition, vector surveillance, and effective awareness campaigns should be emphasized.

Imperfect vaccine can yield multiple Nash equilibria in vaccination games

As infectious diseases continue to threaten communities across the globe, people are faced with a choice to vaccinate, or not. Many factors influence this decision, such as the cost of the disease, the chance of contracting the disease, the population vaccination coverage, and the efficacy of the vaccine. While the vaccination games in which individuals decide whether to vaccinate or not based on their own interests are gaining in popularity in recent years, the vaccine imperfection has been an overlooked aspect so far. In this paper we investigate the effects of an imperfect vaccine on the outcomes of a vaccination game. We use a simple SIR compartmental model for the underlying model of disease transmission. We model the vaccine imperfection by adding vaccination at birth and maintain a possibility for the vaccinated individual to become infected. We derive explicit conditions for the existence of different Nash equilibria, the solutions of the vaccination game. The outcomes of the game depend on the complex interplay between disease transmission dynamics (the basic reproduction number), the relative cost of the infection, and the vaccine efficacy. We show that for diseases with relatively low basic reproduction numbers (smaller than about 2.62), there is a little difference between outcomes for perfect or imperfect vaccines and thus the simpler models assuming perfect vaccines are good enough. However, when the basic reproduction number is above 2.62, then, unlike in the case of a perfect vaccine, there can be multiple equilibria. Moreover, unless there is a mandatory vaccination policy in place that would push the vaccination coverage above the value of unstable Nash equilibrium, the population could eventually slip to the “do not vaccinate” state. Thus, for diseases that have relatively high basic reproduction numbers, the potential for the vaccine not being perfect should be explicitly considered in the models.

Shift from a Zero-COVID strategy to a New-normal strategy for controlling SARS-COV-2 infections in Vietnam.

The aim of this study is to analyse the changing patterns in the transmission of COVID-19 in relation to changes in Vietnamese governmental policies, based on epidemiological data and policy actions in a large Vietnamese province, Bac Ninh, in 2021. Data on confirmed cases from January to December 2021 were collected, together with policy documents. There were three distinct periods of the COVID-19 pandemic in Bac Ninh province during 2021. During the first period, referred to as the 'Zero-COVID' period (01/04-07/04/2021), there was a low population vaccination rate, with less than 25% of the population receiving its first vaccine dose. Measures implemented during this period focused on domestic movement restrictions, mask mandates, and screening efforts to control the spread of the virus. The subsequent period, referred to as the 'Transition' period (07/05-10/22/2021), witnessed a significant increase in population vaccination coverage, with 80% of the population receiving their first vaccine dose. During this period, several days passed without any reported COVID-19 cases in the community. The local government implemented measures to manage domestic actions and reduce the time spent in quarantine, and encouraged home quarantining for the close contacts of cases with COVID-19. Finally, the 'New-normal' stage (10/23-12/31/2021), during which the population vaccination coverage with a second vaccine dose increased to 70%, and most of the mandates for the prevention and control of COVID-19 were reduced. In conclusion, this study highlights the importance of governmental policies in managing and controlling the transmission of COVID-19 and provides insights for developing realistic and context-specific strategies in similar settings.

Hepatitis B Virus (HBV) Infection in Patients at Pasteur Institute of Dakar in Senegal from 2016 to 2020: Prevalence and Seroprotection Level

Hepatitis B virus (HBV) infection is highly endemic in Senegal. Vaccination of all children against HBV was introduced in 1999 and included in Expanded Programme on Immunisation in 2005. The aim of this study was to assess the prevalence and immune status against HBV in patients received at Pasteur Institut in Dakar, Senegal. Methods: Between January 2016 and December 2020, patients aged between 1 and 96 years received laboratory were included in the study. Serum samples were analysed for HBV serology (HBs antigen: HBsAg, HBs antibody: HBsAb and HBc antibody: HBcAb) using ARCHITECT? analyser. Patients with anti-HBs antibody levels (HBsAb ≥ 10 IU/l) were considered seroprotected against HBV. Results: A total of 5629 patients were analysed with a mean age of 39 years and extremes from 1 to 96 years. The most represented age group was 31 - 45 years with 38.4%. HBsAg was present in 520 patients (9.2%) and was signed by sex and age group. Anti-HBc antibodies were found in 52.7% of patients and 1603 (28.48%) had isolated anti-HBs antibodies reflecting proportion of people vaccinated at the time of the study. However, 2143 patients (41.9%) had no seroprotection (HBsAb 10 IU/L) and 640 (12.6%) had strong seroprotection defined as HBsAb > 1000 IU/L. Conclusion: Our results show a significant presence of virus in Senegalese population and low vaccination coverage, especially in adults. Evaluation of HBsAb levels and provision of HBV booster shots should be considered for children in Senegal.

Comparison of the Basic Reproduction Numbers for COVID-19 through Four Waves of the Pandemic in Vietnam

Estimating the basic reproduction number (R0) of an infectious disease is a crucial step to describe the contagiousness and provides suggestions for interventions. To lift the effectiveness of preventive measures for the COVID-19 pandemic, we need to minimize the newly infected cases by reaching adequate herd immunity. This study thus aimed to compare the R0 through four waves of COVID-19 outbreaks in Vietnam and to calculate the minimal vaccination coverage in different populations. The data on the number of daily confirmed COVID-19 patients were collected from 21 January 2020 to 16 November 2021 from the daily reports through the four waves of the pandemic in Vietnam. The R0 values were estimated by exponential growth and the maximum likelihood methods to range from 1.04 to 3.31 from the first to the third wave. The fourth wave was the most severe, especially in the southern provinces, and the highest R0 was in Ho Chi Minh City. The herd immunity would range from 43.50% to 95.76% by various R0 values from different populations. Overall, the presence of new viral mutants increased the infectiousness and the vaccination coverage was higher to establish the required herd immunity in a high-density population. The results provide the basis for policy recommendations and resource allocation for vaccine management and distribution at a time when the COVID-19 pandemic is not yet over.

Effectiveness of Japanese encephalitis vaccination among children in central India.

Japanese encephalitis (JE) disease among children continues in central India despite vaccination implemented in the routine immunization program. Therefore, we planned to estimate the JE vaccination effectiveness among children by undertaking a 1:2 individually-matched population-based case-control study from August 2018 to October 2020. The laboratory-confirmed JE cases aged 1-15 years were enrolled along with neighborhood controls without fever and encephalitis matched on the residence area, age and sex. The JE vaccination history was enquired from parents and verified independently from the vaccination cards available at home and records at health facilities. We enrolled 35 JE cases and 70 matched controls. The vaccination effectiveness of 86.7% (95% confidence interval [CI]: 30.8-94.7) was estimated on the per-protocol analysis of 31 case-control sets. The screening method provided an effectiveness of 89.5% (CI: 78.9-94.7) on using the population vaccination coverage of 90% reported earlier in the same area. In conclusion, JE vaccination offered a moderate level of protection among children in JE medium-endemic central India, similar to reports from high-endemic areas in India. The operational aspects of vaccination program implementation need to be evaluated to assess the impact of vaccination on the disease burden of JE in medium-endemic regions of India.

Yellow fever virus disease: a systematic review of reemergence, incidence and mortality in Isiolo county, Kenya

Yellow fever is an endemic arboviral disease caused by yellow fever virus (YFV), with high fatality. WHO (Eliminate Yellow Fever Epidemics) is a plan to control YFV, with strategies to be carried out from 2017 to 2026. YFV outbreaks occurred in nine African countries in 2021. The burden was estimated in 2013 to be between 84,000 and 170,000 severe cases and 29,000 to 60,000 deaths. Most of the world’s cases were reported in West and East Africa. Understanding the occurrence of yellow fever epidemics is critical for targeted interventions and control efforts to reduce the burden of disease. A systematic review study design was used to review existing literature and data on the yellow fever incidence and mortality rates in the region. Predictors of occurrence of yellow fever outbreaks were identified to include; local mosquito populations and specific yellow fever virus strain, eco climatic conditions, sociopolitical and demographic factors including population size, density, mobility, and vaccine coverage. Kenya declared an outbreak of yellow fever in Isiolo County after the death of three people. About 20 cases were reported in Isiolo in February. Counties bordering Isiolo were placed in the high-risk bracket. A national incident management structure to manage the outbreak was established. The team visited the epicenter of the outbreak in Merti and Garbatulla. Active case search and surveillance was done. It was noted that there was delay in case investigation. This was attributed to low index of suspicion among clinicians. It was concluded that there could be a possibility of both malaria and yellow fever outbreak in the county. The county health team was advised to heighten continued active case search and surveillance, case management and improve on risk communication to the community.

An epidemiological overview of the equine influenza epidemic in Great Britain during 2019.

During 2019, an epidemic of equine influenza (EI) occurred in Europe. To describe the epidemiology of the 2019 EI epidemic within Great Britain (GB). Retrospective descriptive study of laboratory confirmed EI cases. Epidemiological data were obtained from veterinary surgeons referring samples for EI virus testing. Where available, data on confirmed cases and their wider resident population on EI-infected premises were collated and described. On a national level, spatial and temporal representations, consisting of choropleth maps and epidemic curves, described the spread of EI. EI-infected premises-level factors associated with the first of two epidemic phases were investigated using ordinary logistic regression analysis. There were 412 confirmed cases and 234 EI-infected premises, with the first of two epidemic phases occurring between January and April, followed by a second phase through to August. The median age of confirmed cases was 5 years and Sports horses (24%) and Cobs (16%) made up the highest proportions by general horse type and breed. Among confirmed cases 72% were unvaccinated and 18% were vaccinated against EI. New horses arriving within 2 weeks of a confirmed case were reported by 42% of EI-infected premises. Investigation of EI-infected premises biosecurity measures indicated that 23% quarantined new arrivals, 37% had isolation facilities and 57% of resident horses were vaccinated. EI-infected premises were more likely in the first than second epidemic phase to be classified as professional, have a vaccinated confirmed case and EI confirmed in a newly arrived animal. Data were collected at a single time point for each EI-infected premises with no follow ups performed. During 2019, EI-infected premises generally had low levels of population vaccine coverage and implemented limited preventive biosecurity measures, particularly linked to horse movements. Without substantial improvements in infectious disease prevention and control, the GB equine population remains at risk of future EI epidemics.

Decoding the effects of spike receptor binding domain mutations on antibody escape abilities of omicron variants

Recent times witnessed an upsurge in the number of COVID19 cases which is primarily attributed to the emergence of several omicron variants, although there is substantial population vaccination coverage across the globe. Currently, many therapeutic antibodies have been approved for emergency usage. The present study critically evaluates the effect of mutations observed in several omicron variants on the binding affinities of different classes of RBD-specific antibodies using a combined approach of immunoinformatics and binding free energy calculations. Our binding affinity data clearly show that omicron variants achieve antibody escape abilities by incorporating mutations at the immunogenic hotspot residues for each specific class of antibody. K417N and Y505H point mutations are primarily accountable for the loss of class I antibody binding affinities. The K417N/Q493R/Q498R/Y505H combined mutant significantly reduces binding affinities for all the class I antibodies. E484A single mutation, on the other hand, drastically reduces binding affinities for most of the class II antibodies. E484A and E484A/Q493R double mutations cause a 33–38% reduction in binding affinity for an approved therapeutic monoclonal antibody. The Q498R RBD mutation observed across all the omicron variants can reduce ∼12% binding affinity for REGN10987, a class III therapeutic antibody, and the L452R/Q498R double mutation causes a ∼6% decrease in binding affinities for another class III therapeutic antibody, LY-CoV1404. Our data suggest that achieving the immune evasion abilities appears to be the selection pressure behind the emergence of omicron variants.

Field evaluation of typhoid conjugate vaccine in a catch-up campaign among children aged 9 months to 15 years in Sindh, Pakistan

BackgroundTyphoid conjugate vaccine (TCV) has recently been introduced in the expanded program for immunization (EPI) in Pakistan. Before its introduction in routine immunization, a onetime catchup campaign among children 9 months to 15 years old was conducted in November 2019. We performed field evaluation of TCV against culture confirmed Salmonella Typhi (S. Typhi) among 9 months to 15 years old children during the catch up campaign in Karachi and Hyderabad. MethodsA rapid assessment of blood culture confirmed S. Typhi was performed. Age eligible cases of culture confirmed S. Typhi were identified from the laboratory networks of Aga Khan University Hospital Karachi and Hyderabad, Kharadar General Hospital Karachi, and Liaqat University of Medical & Health Sciences (LUMHS) Hyderabad. Information on sociodemographic, typhoid vaccination history and antimicrobial resistance was collected using a structured questionnaire.Patient medical records and lab reports were also reviewed to collect information on diagnosis and antimicrobial susceptibility information. Information about the population vaccination coverage during catch-up campaign was obtained from the provincial EPI office. Field performance of TCV in catchup campaign was measured by calculating the effectiveness using rapid screening method which is less resource-intensive technique of calculating vaccine effectiveness (VE). ResultsOverall, 968 culture confirmed typhoid cases were enrolled. Among them, 82% (793/968) were from Karachi and 18% (175/968) from Hyderabad. The average age of the participants was 5.68 years, and 54% (523/968) were male. 6% (62/968) of the culture confirmed S. Typhi cases were multidrug resistant (MDR), and 61% (586/968) were extensively drug resistant (XDR). The VE using the TCV coverage data provided by EPI was 98%. ConclusionTCV is effective against culture confirmed S. Typhi among children aged 9 months to 15 years in the catch-up campaign setting. While typhoid vaccination can significantly decrease the burden of typhoid disease, improvements in sanitation and hygiene are necessary for the prevention of spread of enteric fever. Longer term follow up will be needed to assess the duration of protection and requirement for booster doses of TCV.