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Featured researches published by Ivelina Yonova.


Eurosurveillance | 2016

Effectiveness of seasonal influenza vaccine for adults and children in preventing laboratory-confirmed influenza in primary care in the United Kingdom: 2015/16 end-of-season results

Richard Pebody; Fiona Warburton; Joanna Ellis; Nick Andrews; Alison Potts; S Cottrel; J Johnston; Arlene Reynolds; Rory Gunson; Catherine Thompson; Monica Galiano; Chris Robertson; Rachel Byford; Naomh Gallagher; Mary Sinnathamby; Ivelina Yonova; Sameera Pathirannehelage; Matthew Donati; Catherine Moore; S de Lusignan; Jim McMenamin; Maria Zambon

The United Kingdom (UK) is in the third season of introducing universal paediatric influenza vaccination with a quadrivalent live attenuated influenza vaccine (LAIV). The 2015/16 season in the UK was initially dominated by influenza A(H1N1)pdm09 and then influenza of B/Victoria lineage, not contained in that season’s adult trivalent inactivated influenza vaccine (IIV). Overall adjusted end-of-season vaccine effectiveness (VE) was 52.4% (95% confidence interval (CI): 41.0–61.6) against influenza-confirmed primary care consultation, 54.5% (95% CI: 41.6–64.5) against influenza A(H1N1)pdm09 and 54.2% (95% CI: 33.1–68.6) against influenza B. In 2–17 year-olds, adjusted VE for LAIV was 57.6% (95% CI: 25.1 to 76.0) against any influenza, 81.4% (95% CI: 39.6–94.3) against influenza B and 41.5% (95% CI: −8.5 to 68.5) against influenza A(H1N1)pdm09. These estimates demonstrate moderate to good levels of protection, particularly against influenza B in children, but relatively less against influenza A(H1N1)pdm09. Despite lineage mismatch in the trivalent IIV, adults younger than 65 years were still protected against influenza B. These results provide reassurance for the UK to continue its influenza immunisation programme planned for 2016/17.


Eurosurveillance | 2015

Uptake and impact of vaccinating school age children against influenza during a season with circulation of drifted influenza A and B strains, England, 2014/15

Richard Pebody; Helen K. Green; Nick Andrews; Nicola L Boddington; Hongxin Zhao; Ivelina Yonova; Joanna Ellis; Sophia Steinberger; Matthew Donati; Alex J. Elliot; Helen Hughes; Sameera Pathirannehelage; David Mullett; Gillian E. Smith; Simon de Lusignan; Maria Zambon

The 2014/15 influenza season was the second season of roll-out of a live attenuated influenza vaccine (LAIV) programme for healthy children in England. During this season, besides offering LAIV to all two to four year olds, several areas piloted vaccination of primary (4-11 years) and secondary (11-13 years) age children. Influenza A(H3N2) circulated, with strains genetically and antigenically distinct from the 2014/15 A(H3N2) vaccine strain, followed by a drifted B strain. We assessed the overall and indirect impact of vaccinating school age children, comparing cumulative disease incidence in targeted and non-targeted age groups in vaccine pilot to non-pilot areas. Uptake levels were 56.8% and 49.8% in primary and secondary school pilot areas respectively. In primary school age pilot areas, cumulative primary care influenza-like consultation, emergency department respiratory attendance, respiratory swab positivity, hospitalisation and excess respiratory mortality were consistently lower in targeted and non-targeted age groups, though less for adults and more severe end-points, compared with non-pilot areas. There was no significant reduction for excess all-cause mortality. Little impact was seen in secondary school age pilot only areas compared with non-pilot areas. Vaccination of healthy primary school age children resulted in population-level impact despite circulation of drifted A and B influenza strains.


BMJ Open | 2016

Royal College of General Practitioners Research and Surveillance Centre (RCGP RSC) sentinel network: a cohort profile

Ana Correa; William Hinton; Andrew McGovern; Jeremy van Vlymen; Ivelina Yonova; Simon Jones; Simon de Lusignan

Purpose The Royal College of General Practitioners Research and Surveillance Centre (RCGP RSC) is one of the longest established primary care sentinel networks. In 2015, it established a new data and analysis hub at the University of Surrey. This paper evaluates the representativeness of the RCGP RSC network against the English population. Participants and method The cohort includes 1 042 063 patients registered in 107 participating general practitioner (GP) practices. We compared the RCGP RSC data with English national data in the following areas: demographics; geographical distribution; chronic disease prevalence, management and completeness of data recording; and prescribing and vaccine uptake. We also assessed practices within the network participating in a national swabbing programme. Findings to date We found a small over-representation of people in the 25–44 age band, under-representation of white ethnicity, and of less deprived people. Geographical focus is in London, with less practices in the southwest and east of England. We found differences in the prevalence of diabetes (national: 6.4%, RCPG RSC: 5.8%), learning disabilities (national: 0.44%, RCPG RSC: 0.40%), obesity (national: 9.2%, RCPG RSC: 8.0%), pulmonary disease (national: 1.8%, RCPG RSC: 1.6%), and cardiovascular diseases (national: 1.1%, RCPG RSC: 1.2%). Data completeness in risk factors for diabetic population is high (77–99%). We found differences in prescribing rates and costs for infections (national: 5.58%, RCPG RSC: 7.12%), and for nutrition and blood conditions (national: 6.26%, RCPG RSC: 4.50%). Differences in vaccine uptake were seen in patients aged 2 years (national: 38.5%, RCPG RSC: 32.8%). Owing to large numbers, most differences were significant (p<0.00015). Future plans The RCGP RSC is a representative network, having only small differences with the national population, which have now been quantified and can be assessed for clinical relevance for specific studies. This network is a rich source for research into routine practice.


Eurosurveillance | 2017

End-of-season influenza vaccine effectiveness in adults and children, United Kingdom, 2016/17

Richard Pebody; Fiona Warburton; Joanna Ellis; Nick Andrews; Alison Potts; Simon Cottrell; Arlene Reynolds; Rory Gunson; Catherine Thompson; Monica Galiano; Chris Robertson; Naomh Gallagher; Mary Sinnathamby; Ivelina Yonova; Ana Correa; Catherine Moore; Muhammad Sartaj; Simon de Lusignan; Jim McMenamin; Maria Zambon

Introduction The United Kingdom is in the fourth season of introducing a universal childhood influenza vaccine programme. The 2016/17 season saw early influenza A(H3N2) virus circulation with care home outbreaks and increased excess mortality particularly in those 65 years or older. Virus characterisation data indicated emergence of genetic clusters within the A(H3N2) 3C.2a group which the 2016/17 vaccine strain belonged to. Methods: The test-negative case–control (TNCC) design was used to estimate vaccine effectiveness (VE) against laboratory confirmed influenza in primary care. Results: Adjusted end-of-season vaccine effectiveness (aVE) estimates were 39.8% (95% confidence interval (CI): 23.1 to 52.8) against all influenza and 40.6% (95% CI: 19.0 to 56.3) in 18–64-year-olds, but no significant aVE in ≥ 65-year-olds. aVE was 65.8% (95% CI: 30.3 to 83.2) for 2–17-year-olds receiving quadrivalent live attenuated influenza vaccine. Discussion: The findings continue to provide support for the ongoing roll-out of the paediatric vaccine programme, with a need for ongoing evaluation. The importance of effective interventions to protect the ≥ 65-year-olds remains.


British Journal of General Practice | 2017

RCGP Research and Surveillance Centre: 50 years’ surveillance of influenza, infections, and respiratory conditions

Simon de Lusignan; Ana Correa; Gillian E. Smith; Ivelina Yonova; Richard Pebody; Filipa Ferreira; Alex J. Elliot; Douglas M. Fleming

The Royal College of General Practitioners’ (RCGP) programme of influenza and respiratory disease surveillance has been supported by the Department of Health (DH) since 1967. The RCGP ‘Weekly Returns Service (WRS)’ has published a weekly report since, making it the longest established primary care sentinel network in Europe (http://www.rcgp.org.uk/clinical-and-research/our-programmes/research-and-surveillance-centre.aspx [web page includes sign-up instructions]). In 1953, the College established a Records and Statistical Unit in Birmingham and the Epidemiological Observation Unit in Surrey. The WRS was formed through integration of these units into one. There has been continuity of leadership: from Donald Crombie (1953–1989) and Douglas Fleming (1989–2013).1 In 2013 Simon de Lusignan became Director and the network name changed to the RCGP Research and Surveillance Centre (RSC). The RCGP RSC has grown in terms of size, scope, integration of microbiological testing, and data-linkage. Its outputs and impact come from its leading international role in surveillance and research, including the early identification of pandemics and the contribution to the development of what are now standard methods of assessment of vaccine effectiveness. We describe its evolution and its plans for the future. Between 1967 and 1993 the registered population within the RCGP RSC grew to 200 000 and it comprised 40 practices. …


British Journal of General Practice | 2017

RCGP Research and Surveillance Centre Annual Report 2014–2015: disparities in presentations to primary care

Simon de Lusignan; Ana Correa; Sameera Pathirannehelage; Rachel Byford; Ivelina Yonova; Alex J. Elliot; Theresa Lamagni; Gayatri Amirthalingam; Richard Pebody; Gillian E. Smith; Simon Jones; Imran Rafi

BACKGROUND The Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) comprises over 100 general practices in England, with a population of around 1 million, providing a public health surveillance system for England and data for research. AIM To demonstrate the scope of data with the RCGP Annual Report 2014-2015 (May 2014 to April 2015) by describing disparities in the presentation of six common conditions included in the report. DESIGN AND SETTING This is a report of respiratory and communicable disease incidence from a primary care sentinel network in England. METHOD Incidence rates and demographic profiles are described for common cold, acute otitis media, pneumonia, influenza-like illness, herpes zoster, and scarlet fever. The impact of age, sex, ethnicity, and deprivation on the diagnosis of each condition is explored using a multivariate logistic regression. RESULTS With the exception of herpes zoster, all conditions followed a seasonal pattern. Apart from pneumonia and scarlet fever, the odds of presenting with any of the selected conditions were greater for females (P<0.001). Older people had a greater probability of a pneumonia diagnosis (≥75 years, odds ratio [OR] 6.37; P<0.001). Common cold and influenza-like illness were more likely in people from ethnic minorities than white people, while the converse was true for acute otitis media and herpes zoster. There were higher odds of acute otitis media and herpes zoster diagnosis among the less deprived (least deprived quintile, OR 1.32 and 1.48, respectively; P<0.001). CONCLUSION The RCGP RSC database provides insight into the content and range of GP workload and provides insight into current public health concerns. Further research is needed to explore these disparities in presentation to primary care.


BMJ Open | 2017

Post-authorisation passive enhanced safety surveillance of seasonal influenza vaccines: protocol of a pilot study in England

Simon de Lusignan; Gaël Dos Santos; Ana Correa; François Haguinet; Ivelina Yonova; Florence Lair; Rachel Byford; Filipa Ferreira; Karen Stuttard; Tom Chan

Aim To pilot enhanced safety surveillance of seasonal influenza vaccine meeting the European Medicines Agency (EMA) requirement to rapidly detect a significant increase in the frequency or severity of adverse events of interest (AEIs), which may indicate risk from the new season’s vaccine. Study design A prospective passive enhanced safety surveillance combining data collection from adverse drug reaction (ADR) cards with automated collection of pseudonymised routinely collected electronic health record (EHR) data. This study builds on a feasibility study carried out at the start of the 2015/2016 influenza season. We will report influenza vaccine exposure and any AEIs reported via ADR card or recorded directly into the EHR, from the commencement of influenza vaccination and ends as specified by EMA (30 November 2016). Setting Ten volunteer English general practices, primarily using the GSK influenza vaccines. They had selected this vaccine in advance of the study. Participants People who receive a seasonal influenza vaccine, in each age group defined in EMA interim guidance: 6 months to 5 years, 6–12 years, 13–17 years, 18–65 years and >65 years. Outcome measures The primary outcome measure is the rate of AEIs occurring within 7 days postvaccination, using passive surveillance of general practitioner (GP) EHR systems enhanced by a card-based ADR reporting system. Extracted data will be presented overall by brand (Fluarix Tetra vs others), by age strata and risk groups. The secondary outcome measure is the vaccine uptake among the subjects registered in the enrolled general practices. Ethics and dissemination Ethical approval was granted by the Proportionate Review Sub-committee of the North East—Newcastle & North Tyneside 2 on 5 August 2016. The study received approval from the Health Research Authority on 1 September 2016. We will produce an interim analysis within 8 weeks, and an end-of-study report, which will be submitted to peer-reviewed journals.


JMIR public health and surveillance | 2018

Conurbation, urban and rural living are contributing determinants of allergic and infectious disease: Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) Annual Report 2016-2017 (Preprint)

Simon de Lusignan; Christopher McGee; Rebecca Webb; Mark Joy; Rachel Byford; Ivelina Yonova; Mariya Hriskova; Filipa Ferreira; Alex J. Elliot; Gillian E. Smith; Imran Rafi

Background Living in a conurbation, urban, or rural environment is an important determinant of health. For example, conurbation and rural living is associated with increased respiratory and allergic conditions, whereas a farm or rural upbringing has been shown to be a protective factor against this. Objective The objective of the study was to assess differences in general practice presentations of allergic and infectious disease in those exposed to conurbation or urban living compared with rural environments. Methods The population was a nationally representative sample of 175 English general practices covering a population of over 1.6 million patients registered with sentinel network general practices. General practice presentation rates per 100,000 population were reported for allergic rhinitis, asthma, and infectious conditions grouped into upper and lower respiratory tract infections, urinary tract infection, and acute gastroenteritis by the UK Office for National Statistics urban-rural category. We used multivariate logistic regression adjusting for age, sex, ethnicity, deprivation, comorbidities, and smoking status, reporting odds ratios (ORs) with 95% CIs. Results For allergic rhinitis, the OR was 1.13 (95% CI 1.04-1.23; P=.003) for urban and 1.29 (95% CI 1.19-1.41; P<.001) for conurbation compared with rural dwellers. Conurbation living was associated with a lower OR for both asthma (OR 0.70, 95% CI 0.67-0.73; P<.001) and lower respiratory tract infections (OR 0.94, 95% CI 0.90-0.98; P=.005). Compared with rural dwellers, the OR for upper respiratory tract infection was greater in urban (OR 1.06, 95% CI 1.03-1.08; P<.001) but no different in conurbation dwellers (OR 1.00, 95% CI 0.97-1.03; P=.93). Acute gastroenteritis followed the same pattern: the OR was 1.13 (95% CI 1.01-1.25; P=.03) for urban dwellers and 1.04 (95% CI 0.93-1.17; P=.46) for conurbation dwellers. The OR for urinary tract infection was lower for urban dwellers (OR 0.94, 95% CI 0.89-0.99; P=.02) but higher in conurbation dwellers (OR 1.06, 95% CI 1.00-1.13; P=.04). Conclusions Those living in conurbations or urban areas were more likely to consult a general practice for allergic rhinitis and upper respiratory tract infection. Both conurbation and rural living were associated with an increased risk of urinary tract infection. Living in rural areas was associated with an increased risk of asthma and lower respiratory tract infections. The data suggest that living environment may affect rates of consultations for certain conditions. Longitudinal analyses of these data would be useful in providing insights into important determinants.


Eurosurveillance | 2018

Uptake and impact of vaccinating primary school-age children against influenza: experiences of a live attenuated influenza vaccine programme, England, 2015/16

Richard Pebody; Mary Sinnathamby; Fiona Warburton; Nick Andrews; Nicola L Boddington; Hongxin Zhao; Ivelina Yonova; Joanna Ellis; Elise Tessier; Matthew Donati; Alex J. Elliot; Helen Hughes; Sameera Pathirannehelage; Rachel Byford; Gillian E. Smith; Simon de Lusignan; Maria Zambon

The 2015/16 influenza season was the third season of the introduction of an intra-nasally administered live attenuated influenza vaccine (LAIV) for children in England. All children aged 2‒6 years were offered LAIV, and in addition, a series of geographically discrete areas piloted vaccinating school-age children 7‒11 years old. Influenza A(H1N1)pdm09 was the dominant circulating strain during 2015/16 followed by influenza B. We measured influenza vaccine uptake and the overall and indirect effect of vaccinating children of primary school -age, by comparing cumulative disease incidence in targeted and non-targeted age groups in vaccine pilot and non-pilot areas in England. Uptake of 57.9% (range: 43.6-72.0) was achieved in the five pilot areas for children aged 5‒11 years. In pilot areas, cumulative emergency department respiratory attendances, influenza-confirmed hospitalisations and intensive care unit admissions were consistently lower, albeit mostly non-significantly, in targeted and non-targeted age groups compared with non-pilot areas. Effect sizes were less for adults and more severe endpoints. Vaccination of healthy primary school-age children with LAIV at moderately high levels continues to be associated with population-level reductions in influenza-related respiratory illness. Further work to evaluate the population-level impact of the programme is required.


medical informatics europe | 2018

Automated Differentiation of Incident and Prevalent Cases in Primary Care Computerised Medical Records (CMR).

Nadia Smith; Valerie Livina; Rachel Byford; Filipa Ferreira; Ivelina Yonova; Simon de Lusignan

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