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1.
Euro Surveill ; 27(15)2022 Apr.
Article in English | MEDLINE | ID: covidwho-1793106

ABSTRACT

In the WHO European Region, COVID-19 non-pharmaceutical interventions continued slowing influenza circulation in the 2021/22 season, with reduced characterisation data. A(H3) predominated and, in some countries, co-circulated with A(H1)pdm09 and B/Victoria viruses. No B/Yamagata virus detections were confirmed. Substantial proportions of characterised circulating virus subtypes or lineages differed antigenically from their respective northern hemisphere vaccine components. Appropriate levels of influenza virus characterisations should be maintained until the season end and in future seasons, when surveillance is adapted to integrate SARS-CoV-2.

2.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-332375

ABSTRACT

First Few X cases (FFX) investigations and Household transmission investigations (HHTI) are essential epidemiological tools for early characterisation of novel infectious pathogens and their variants. We aimed to estimate the household secondary infection attack rate (hSAR) of SARS-CoV-2 in investigations aligned with the WHO Unity Studies HHTI protocol. We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines (PROSPERO registration:CRD42021260065). We searched Medline, Embase, Web of Science, Scopus and medRxiv/bioRxiv for ‘Unity-aligned’ FFX and HHTI published between 1 December 2019 and 26 July 2021. Standardised early results were shared by WHO Unity Studies Collaborators (to 1 October 2021). We used a bespoke tool to assess investigation methodological quality. Values for hSAR and 95% confidence intervals (CIs) were extracted or calculated from crude data. Heterogeneity was assessed by visually inspecting overlap of CIs on forest plots and quantified in meta-analyses. Of 9988 records retrieved, 80 articles (64 from databases;16 provided by WHO Unity Studies collaborators) were retained in the systematic review and 62 were included in the primary meta-analysis. hSAR point estimates ranged from 2%–90% (95% prediction interval: 3%–71%;I 2 =99.7%);I 2 values remained >99% in subgroup analyses, indicating high, unexplained heterogeneity and leading to a decision not to report pooled hSAR estimates. The large, unexplained variance in hSAR estimates emphasises the need for improved standardisation in planning, conduct and analysis, and for clear and comprehensive reporting of FFX and HHTIs, to guide evidence-based pandemic preparedness and response efforts for SARS-CoV-2, influenza and future novel respiratory viruses.

3.
BMJ Open ; 12(3): e057741, 2022 03 23.
Article in English | MEDLINE | ID: covidwho-1759370

ABSTRACT

INTRODUCTION: Critical questions remain about COVID-19 vaccine effectiveness (VE) in real-world settings, particularly in middle-income countries. We describe a study protocol to evaluate COVID-19 VE in preventing laboratory-confirmed SARS-CoV-2 infection in health workers (HWs) in Albania, an upper-middle-income country. METHODS AND ANALYSIS: In this 12-month prospective cohort study, we enrolled HWs at three hospitals in Albania. HWs are vaccinated through the routine COVID-19 vaccine campaign. Participants completed a baseline survey about demographics, clinical comorbidities, and infection risk behaviours. Baseline serology samples were also collected and tested against the SARS-CoV-2 spike protein, and respiratory swabs were collected and tested for SARS-CoV-2 by RT-PCR. Participants complete weekly symptom questionnaires and symptomatic participants have a respiratory swab collected, which is tested for SARS-CoV-2. At 3, 6, 9 months and 12 months of the study, serology will be collected and tested for antibodies against the SARS-CoV-2 nucleocapsid protein and spike protein. VE will be estimated using a piecewise proportional hazards model (VE=1-HR). BASELINE DATA: From February to May 2021, 1504 HWs were enrolled. The median age was 44 (range: 22-71) and 78% were female. At enrolment, 72% of participants were seropositive for SARS-CoV-2. 56% of participants were vaccinated with one dose, of whom 98% received their first shot within 4 days of enrolment. All HWs received the Pfizer BNT162b2 mRNA COVID-19 vaccine. ETHICS AND DISSEMINATION: The study protocol and procedures were reviewed and approved by the WHO Ethical Review Board, reference number CERC.0097A, and the Albanian Institute of Public Health Ethical Review Board, reference number 156. All participants have provided written informed consent to participate in this study. The primary results of this study will be published in a peer-reviewed journal at the time of completion. TRIAL REGISTRATION NUMBER: NCT04811391.


Subject(s)
COVID-19 , Viral Vaccines , Adult , Albania/epidemiology , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Female , Health Personnel , Humans , Prospective Studies , SARS-CoV-2 , Spike Glycoprotein, Coronavirus
4.
Influenza Other Respir Viruses ; 2022 Mar 22.
Article in English | MEDLINE | ID: covidwho-1752578

ABSTRACT

INTRODUCTION: We evaluated uptake and factors associated with COVID-19 vaccination among health workers (HWs) in Azerbaijan. RESULTS: Among 1575 HWs, 73% had received at least one dose, and 67% received two doses; all received CoronaVac. Factors associated with vaccination uptake included no previous COVID-19 infection, older age, belief in the vaccine's safety, previous vaccination for influenza, having patient-facing roles and good or excellent health by self-assessment. CONCLUSION: These findings could inform strategies to increase vaccination uptake as the campaign continues.

5.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-329239

ABSTRACT

We evaluated uptake and factors associated with COVID-19 vaccination among health workers (HWs) in Azerbaijan. Among 1,575 HWs, 73% had received at least one dose and 67% received two doses;all received CoronaVac. Factors associated with vaccination uptake included no previous COVID-19 infection, older age, belief in the vaccine’s safety, previous vaccination for influenza, having patient-facing roles, and good or excellent health by self-assessment. These findings could inform strategies to increase vaccination uptake as the campaign continues.

6.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-310743

ABSTRACT

Background: Underlying conditions have been found to be associated with severe COVID-19 outcomes, such as hospitalisation and death. This study aimed to estimate age-specific adjusted relative and absolute effects of individual underlying conditions on hospitalisation, death and in-hospital death among COVID-19 cases.Methods: We analysed case-based COVID-19 data submitted to The European Surveillance System (TESSy) between 2 June and 13 December 2020 by nine European countries. We individually assessed the association between 11 underlying conditions with hospitalisation, death and in-hospital death. Two additional categorical exposures were created: number of underlying conditions (1,2, ≥ 3) and the presence of any underlying condition (≥ 1). Adjusted ORs (aOR) for the association between each exposure condition and outcome were estimated using two multivariable logistic regression models: 1) an age-adjusted model and 2) an age-interaction model (exposure condition*age). All models were adjusted for sex, reporting period (June-September;October-December) and reporting country. From the age-interaction model we estimated the predicted probability of the three outcomes for each level of condition and age-group, marginalised over the levels of each covariable.Findings: After controlling for age, sex, reporting period and reporting country in the age-adjusted models, cases with cancer, cardiac disorder, diabetes, immune deficiency disorder, kidney disease, liver disease, lung disease, neurological disorders, obesity, any underlying condition or up to three or more conditions were between 1·5 and 5·6 times more likely to be hospitalised or die than cases with no underlying condition. Asthma was associated with increased overall risk of hospitalisation, not death. Age was an important modifier of these associations, with an age interaction present in the majority of models. For all outcomes, age-specific aOR in the age-interaction models tended to decrease with increasing age, whereas predicted probabilities of the outcome increased with age. For instance, individuals aged <20 years with any underlying condition were significantly more likely to be hospitalised (aOR: 5·16, 95%CI: 4·42 - 6·02) and die (aOR: 33·77, 95%CI: 12·57 - 90·75) compared to same-aged individuals without condition. The aOR fell to 1·77 (95%CI: 1·71 - 1·83) and 1·61 (95%CI: 1·55 - 1·68) respectively in individuals 80 years and older. Conversely, the predicted probabilities of hospitalisation and death among cases aged <20 years were 5·69% (95%CI: 4·97 - 6·51) and 0.15% (95%CI: 0·08 - 0·31), respectively, while they were 44·55% (95%CI: 43·68 - 45·43) and 16·31% (95%CI: 15·44 - 17·21), respectively for individuals aged 80 years and older. For some conditions, the probability of the outcome was at least as high in younger individuals with the condition as older cases without the condition.Interpretation: Several underlying conditions were found to have a significant independent effect on severe COVID-19 outcomes. Age is an important effect modifier in these associations. Interpretation of the results in this study is facilitated by considering together the estimates of relative (aOR) and absolute (predicted probabilities) effects that are presented. The presence of underlying conditions tended to have a larger relative effect in the young than the old, but the absolute probability of being hospitalised or dying increased with age. The finding that for some conditions, a younger person may have the same or even higher probability of severe outcome than an older person without it, has relevance for age and risk-factor based prioritisation of vaccination, particularly in the young.Funding Information: This study was funded through ECDC internal funding.Declaration of Interests: None to declare.

7.
Int J Infect Dis ; 112: 352-361, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1654550

ABSTRACT

BACKGROUND: The secondary attack rate (SAR) of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was estimated, and the risk factors for infection among members of households with a coronavirus disease 2019 (COVID-19) index case were identified to inform preventive measures. METHODS: Between 3 August and 19 December 2020, a household transmission study was implemented based on a standardized World Health Organization protocol. Laboratory-confirmed cases of SARS-CoV-2 infection were recruited through the federal COVID-19 database. Trained contact tracers interviewed index cases and household members to collect information on demographic, clinical and behavioural factors. Contacts were followed up for 28 days to identify secondary infections. SAR was estimated and odds ratios (OR) were calculated for risk factors for transmission. RESULTS: In total, 383 households and 793 contacts were included in this study. The overall SAR was 17% [95% confidence interval (CI) 14-21]. Contacts had higher risk for infection if the primary case had both cough and runny nose (OR 4.31, 95% CI 1.60-11.63), if the contact was aged 18-49 years (OR 4.67, 95% CI 1.83-11.93), if the contact kissed the primary case (OR 3.16, 95% CI 1.19-8.43), or if the contact shared a meal with the primary case (OR 3.10, 95% CI 1.17-8.27). CONCLUSIONS: These results add to the global literature by providing evidence from a middle-income setting. Standard preventive measures in households with positive cases remain critical to reduce transmission.


Subject(s)
COVID-19 , SARS-CoV-2 , Bosnia and Herzegovina/epidemiology , Contact Tracing , Family Characteristics , Humans , Prospective Studies
8.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296545

ABSTRACT

Background: COVID-19 case data underestimates infection and immunity, especially in low- and middle-income countries (LMICs). We meta-analyzed standardized SARS-CoV-2 seroprevalence studies to estimate global seroprevalence. Objectives/Methods We conducted a systematic review and meta-analysis, searching MEDLINE, Embase, Web of Science, preprints, and grey literature for SARS-CoV-2 seroprevalence studies aligned with the WHO UNITY protocol published between 2020-01-01 and 2021-10-29. Eligible studies were extracted and critically appraised in duplicate. We meta-analyzed seroprevalence by country and month, pooling to estimate regional and global seroprevalence over time;compared seroprevalence from infection to confirmed cases to estimate under-ascertainment;meta-analyzed differences in seroprevalence between demographic subgroups;and identified national factors associated with seroprevalence using meta-regression. PROSPERO: CRD42020183634. Results We identified 396 full texts reporting 736 distinct seroprevalence studies (41% LMIC), including 355 low/moderate risk of bias studies with national/sub-national scope in further analysis. By April 2021, global SARS-CoV-2 seroprevalence was 26.1%, 95% CI [24.6-27.6%]. Seroprevalence rose steeply in the first half of 2021 due to infection in some regions (e.g., 18.2% to 45.9% in Africa) and vaccination and infection in others (e.g., 11.3% to 57.4% in the Americas high-income countries), but remained low in others (e.g., 0.3% to 1.6% in the Western Pacific). In 2021 Q1, median seroprevalence to case ratios were 1.9:1 in HICs and 61.9:1 in LMICs. Children 0-9 years and adults 60+ were at lower risk of seropositivity than adults 20-29. In a multivariate model using data pre-vaccination, more stringent public health and social measures were associated with lower seroprevalence. Conclusions Global seroprevalence has risen considerably over time and with regional variation, however much of the global population remains susceptible to SARS-CoV-2 infection. True infections far exceed reported COVID-19 cases. Standardized seroprevalence studies are essential to inform COVID-19 control measures, particularly in resource-limited regions.

9.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296217

ABSTRACT

Seroprevalence surveys are essential to assess the age-specific prevalence of pre-existing cross-reactive antibodies in the population with the emergence of a novel pathogen;to measure population cumulative seroincidence of infection, and to contribute to estimating infection severity. With the emergence of SARS-CoV-2, ECDC and WHO Regional Office for Europe have supported Member States in undertaking standardized population-based SARS-CoV-2 seroprevalence surveys across the WHO European Region. The objective of this study was to undertake a systematic literature review of SARS-CoV-2 population seroprevalence studies undertaken in the WHO European Region to measure pre-existing and cumulative seropositivity prior to the roll out of vaccination programmes. We systematically searched MEDLINE, ELSEVIER and the pre-print servers medRxiv and bioRxiv within the COVID-19 Global literature on coronavirus disease database using a predefined search strategy. We included seroepidemiology studies published before the widespread implementation of COVID-19 vaccination programmes in January 2021 among the general population and blood donors, at national and regional levels. Study risk of bias was assessed using a quality scoring system based on sample size, sampling and testing methodologies. Articles were supplemented with unpublished WHO-supported Unity-aligned seroprevalence studies and other studies reported directly to WHO Regional Office for Europe and ECDC. In total, 111 studies from 26 countries published or conducted between 01/01/2020 and 31/12/2020 across the WHO European Region were included. A significant heterogeneity in implementation was noted across the studies, with a paucity of studies from the east of the Region. Eighty-one (73%) studies were assessed to be of low to medium risk of bias. Overall, SARS-CoV-2 seropositivity prior to widespread community circulation was very low. National seroprevalence estimates after circulation started ranged from 0% to 51.3% (median 2.2% (IQR 0.7-5.2%);n=124), while sub-national estimates ranged from 0% to 52% (median 5.8% (IQR 2.3-12%);n=101), with the highest estimates in areas following widespread local transmission. The review found evidence of low national SARS-CoV-2 seroprevalence (<10%) across the WHO European Region in 2020. The low levels of SARS-CoV-2 antibody in most populations prior to the start of vaccine programmes highlights the critical importance of vaccinating priority groups at risk of severe disease while maintaining reduced levels of transmission to minimize population morbidity and mortality.

10.
2021.
Preprint in English | Other preprints | ID: ppcovidwho-294699

ABSTRACT

We assessed the impact of COVID-19 on healthcare workers (HCWs) from data on 2.9 million cases reported from nine countries in the EU/EEA. Compared to non-HCWs, HCWs had a higher adjusted risk of hospitalization (IRR 3.0 [95% CI 2.2-4.0]), but not death (IRR 0.9, 95% CI 0.4-2.0). Article Summary Line Healthcare workers are hospitalized more frequently than non-healthcare workers when adjusting for age, sex, and comorbidities.

11.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-293609

ABSTRACT

Seroprevalence surveys are essential to assess the age-specific prevalence of pre-existing cross-reactive antibodies in the population with the emergence of a novel pathogen;to measure population cumulative seroincidence of infection, and to contribute to estimating infection severity. With the emergence of SARS-CoV-2, ECDC and WHO Regional Office for Europe have supported Member States in undertaking standardized population-based SARS-CoV-2 seroprevalence surveys across the WHO European Region. The objective of this study was to undertake a systematic literature review of SARS-CoV-2 population seroprevalence studies undertaken in the WHO European Region to measure pre-existing and cumulative seropositivity prior to the roll out of vaccination programmes. We systematically searched MEDLINE, ELSEVIER and the pre-print servers medRxiv and bioRxiv within the COVID-19 Global literature on coronavirus disease database using a predefined search strategy. We included seroepidemiology studies published before the widespread implementation of COVID-19 vaccination programmes in January 2021 among the general population and blood donors, at national and regional levels. Study risk of bias was assessed using a quality scoring system based on sample size, sampling and testing methodologies. Articles were supplemented with unpublished WHO-supported Unity-aligned seroprevalence studies and other studies reported directly to WHO Regional Office for Europe and ECDC. In total, 111 studies from 26 countries published or conducted between 01/01/2020 and 31/12/2020 across the WHO European Region were included. A significant heterogeneity in implementation was noted across the studies, with a paucity of studies from the east of the Region. Eighty-one (73%) studies were assessed to be of low to medium risk of bias. Overall, SARS-CoV-2 seropositivity prior to widespread community circulation was very low. National seroprevalence estimates after circulation started ranged from 0% to 51.3% (median 2.2% (IQR 0.7-5.2%);n=124), while sub-national estimates ranged from 0% to 52% (median 5.8% (IQR 2.3-12%);n=101), with the highest estimates in areas following widespread local transmission. The review found evidence of low national SARS-CoV-2 seroprevalence (<10%) across the WHO European Region in 2020. The low levels of SARS-CoV-2 antibody in most populations prior to the start of vaccine programmes highlights the critical importance of vaccinating priority groups at risk of severe disease while maintaining reduced levels of transmission to minimize population morbidity and mortality.

12.
Lancet Reg Health Eur ; 12: 100267, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1540829

ABSTRACT

Background: Countries in the World Health Organization (WHO) European Region differ in terms of the COVID-19 vaccine supply conditions. We evaluated the health and economic impact of different age-based vaccine prioritisation strategies across this demographically and socio-economically diverse region. Methods: We fitted age-specific compartmental models to the reported daily COVID-19 mortality in 2020 to inform the immunity level before vaccine roll-out. Models capture country-specific differences in population structures, contact patterns, epidemic history, life expectancy, and GDP per capita.We examined four strategies that prioritise: all adults (V+), younger (20-59 year-olds) followed by older adults (60+) (V20), older followed by younger adults (V60), and the oldest adults (75+) (V75) followed by incrementally younger age groups. We explored four roll-out scenarios (R1-4) - the slowest scenario (R1) reached 30% coverage by December 2022 and the fastest (R4) 80% by December 2021. Five decision-making metrics were summarised over 2021-22: mortality, morbidity, and losses in comorbidity-adjusted life expectancy, comorbidity- and quality-adjusted life years, and human capital. Six vaccine profiles were tested - the highest performing vaccine has 95% efficacy against both infection and disease, and the lowest 50% against diseases and 0% against infection. Findings: Of the 20 decision-making metrics and roll-out scenario combinations, the same optimal strategy applied to all countries in only one combination; V60 was more or similarly desirable than V75 in 19 combinations. Of the 38 countries with fitted models, 11-37 countries had variable optimal strategies by decision-making metrics or roll-out scenarios. There are greater benefits in prioritising older adults when roll-out is slow and when vaccine profiles are less favourable. Interpretation: The optimal age-based vaccine prioritisation strategies were sensitive to country characteristics, decision-making metrics, and roll-out speeds. A prioritisation strategy involving more age-based stages (V75) does not necessarily lead to better health and economic outcomes than targeting broad age groups (V60). Countries expecting a slow vaccine roll-out may particularly benefit from prioritising older adults. Funding: World Health Organization, Bill and Melinda Gates Foundation, the Medical Research Council (United Kingdom), the National Institute of Health Research (United Kingdom), the European Commission, the Foreign, Commonwealth and Development Office (United Kingdom), Wellcome Trust.

13.
Euro Surveill ; 26(47)2021 11.
Article in English | MEDLINE | ID: covidwho-1538334

ABSTRACT

Since December 2019, over 1.5 million SARS-CoV-2-related fatalities have been recorded in the World Health Organization European Region - 90.2% in people ≥ 60 years. We calculated lives saved in this age group by COVID-19 vaccination in 33 countries from December 2020 to November 2021, using weekly reported deaths and vaccination coverage. We estimated that vaccination averted 469,186 deaths (51% of 911,302 expected deaths; sensitivity range: 129,851-733,744; 23-62%). Impact by country ranged 6-93%, largest when implementation was early.


Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , SARS-CoV-2 , Vaccination , World Health Organization
14.
Euro Surveill ; 26(40)2021 10.
Article in English | MEDLINE | ID: covidwho-1511988

ABSTRACT

BackgroundAnnual seasonal influenza activity in the northern hemisphere causes a high burden of disease during the winter months, peaking in the first weeks of the year.AimWe describe the 2019/20 influenza season and the impact of the COVID-19 pandemic on sentinel surveillance in the World Health Organization (WHO) European Region.MethodsWe analysed weekly epidemiological and virological influenza data from sentinel primary care and hospital sources reported by countries, territories and areas (hereafter countries) in the European Region.ResultsWe observed co-circulation of influenza B/Victoria-lineage, A(H1)pdm09 and A(H3) viruses during the 2019/20 season, with different dominance patterns observed across the Region. A higher proportion of patients with influenza A virus infection than type B were observed. The influenza activity started in week 47/2019, and influenza positivity rate was ≥ 50% for 2 weeks (05-06/2020) rather than 5-8 weeks in the previous five seasons. In many countries a rapid reduction in sentinel reports and the highest influenza activity was observed in weeks 09-13/2020. Reporting was reduced from week 14/2020 across the Region coincident with the onset of widespread circulation of SARS-CoV-2.ConclusionsOverall, influenza type A viruses dominated; however, there were varying patterns across the Region, with dominance of B/Victoria-lineage viruses in a few countries. The COVID-19 pandemic contributed to an earlier end of the influenza season and reduced influenza virus circulation probably owing to restricted healthcare access and public health measures.


Subject(s)
COVID-19 , Influenza, Human , Humans , Influenza, Human/epidemiology , Pandemics , SARS-CoV-2 , Seasons , World Health Organization
15.
Front Public Health ; 9: 676838, 2021.
Article in English | MEDLINE | ID: covidwho-1470769

ABSTRACT

Introduction: The COVID-19 crisis provides an opportunity to reflect on what worked during the pandemic, what could have been done differently, and what innovations should become part of an enhanced health information system in the future. Methods: An online qualitative survey was designed and administered online in November 2020 to all the 37 Member States that are part of the WHO European Health Information Initiative and the WHO Central Asian Republics Information Network. Results: Nineteen countries responded to the survey (Austria, Belgium, Croatia, Czech Republic, Finland, Greece, Iceland, Ireland, Israel, Italy, Kazakhstan, Latvia, Lithuania, Romania, Russian Federation, Sweden, Turkey, United Kingdom, and Uzbekistan). The COVID-19 pandemic required health information systems (HIS) to rapidly adapt to identify, collect, store, manage, and transmit accurate and timely COVID-19 related data. HIS stakeholders have been put to the test, and valuable experience has been gained. Despite critical gaps such as under-resourced public health services, obsolete health information technologies, and lack of interoperability, most countries believed that their information systems had worked reasonably well in addressing the needs arising during the COVID-19 pandemic. Conclusion: Strong enabling environments and advanced and digitized health information systems are vital to controlling epidemics. Sustainable finance and government support are required for the continued implementation and enhancement of HIS. It is important to promote digital solutions beyond the COVID-19 pandemic. Now is the time to discuss potential solutions to obtain timely, accurate, and reliable health information and steer policy-making while protecting privacy rights and meeting the highest ethical standards.


Subject(s)
COVID-19 , Health Information Systems , Czech Republic , Humans , Pandemics/prevention & control , SARS-CoV-2
16.
Influenza Other Respir Viruses ; 16(1): 7-13, 2022 01.
Article in English | MEDLINE | ID: covidwho-1455561

ABSTRACT

BACKGROUND: The declaration of Coronavirus disease 2019 (COVID-19) as a Public Health Emergency of International Concern (PHEIC) on 30 January 2020 required rapid implementation of early investigations to inform appropriate national and global public health actions. METHODS: The suite of existing pandemic preparedness generic epidemiological early investigation protocols was rapidly adapted for COVID-19, branded the 'UNITY studies' and promoted globally for the implementation of standardized and quality studies. Ten protocols were developed investigating household (HH) transmission, the first few cases (FFX), population seroprevalence (SEROPREV), health facilities transmission (n = 2), vaccine effectiveness (n = 2), pregnancy outcomes and transmission, school transmission, and surface contamination. Implementation was supported by WHO and its partners globally, with emphasis to support building surveillance and research capacities in low- and middle-income countries (LMIC). RESULTS: WHO generic protocols were rapidly developed and published on the WHO website, 5/10 protocols within the first 3 months of the response. As of 30 June 2021, 172 investigations were implemented by 97 countries, of which 62 (64%) were LMIC. The majority of countries implemented population seroprevalence (71 countries) and first few cases/household transmission (37 countries) studies. CONCLUSION: The widespread adoption of UNITY protocols across all WHO regions indicates that they addressed subnational and national needs to support local public health decision-making to prevent and control the pandemic.


Subject(s)
COVID-19 , Pandemics , Humans , Pandemics/prevention & control , SARS-CoV-2 , Seroepidemiologic Studies , World Health Organization
17.
Vaccine ; 39(30): 4013-4024, 2021 07 05.
Article in English | MEDLINE | ID: covidwho-1253726

ABSTRACT

Phase 3 randomized-controlled trials have provided promising results of COVID-19 vaccine efficacy, ranging from 50 to 95% against symptomatic disease as the primary endpoints, resulting in emergency use authorization/listing for several vaccines. However, given the short duration of follow-up during the clinical trials, strict eligibility criteria, emerging variants of concern, and the changing epidemiology of the pandemic, many questions still remain unanswered regarding vaccine performance. Post-introduction vaccine effectiveness evaluations can help us to understand the vaccine's effect on reducing infection and disease when used in real-world conditions. They can also address important questions that were either not studied or were incompletely studied in the trials and that will inform evolving vaccine policy, including assessment of the duration of effectiveness; effectiveness in key subpopulations, such as the very old or immunocompromised; against severe disease and death due to COVID-19; against emerging SARS-CoV-2 variants of concern; and with different vaccination schedules, such as number of doses and varying dosing intervals. WHO convened an expert panel to develop interim best practice guidance for COVID-19 vaccine effectiveness evaluations. We present a summary of the interim guidance, including discussion of different study designs, priority outcomes to evaluate, potential biases, existing surveillance platforms that can be used, and recommendations for reporting results.


Subject(s)
COVID-19 , Vaccines , COVID-19 Vaccines , Humans , SARS-CoV-2 , World Health Organization
18.
Influenza Other Respir Viruses ; 15(5): 599-607, 2021 09.
Article in English | MEDLINE | ID: covidwho-1214794

ABSTRACT

BACKGROUND: During 2009-2010, pandemic influenza A (H1N1) pdm09 virus (pH1N1) infections in England occurred in two epidemic waves. Reasons for a reported increase in case-severity during the second wave are unclear. METHODS: We analysed hospital-based surveillance for patients with pH1N1 infections in England during 2009-2010 and linked national data sets to estimate ethnicity, socio-economic status and death within 28 days of admission. We used multivariable logistic regression to assess whether changes in demographic, clinical and management characteristics of patients could explain an increase in ICU admission or death, and accounted for missing values using multiple imputation. RESULTS: During the first wave, 54/960 (6%) hospitalised patients required intensive care and 21/960 (2%) died; during the second wave 143/1420 (10%) required intensive care and 55/1420 (4%) died. In a multivariable model, during the second wave patients were less likely to be from an ethnic minority (OR 0.33, 95% CI 0.26-0.42), have an elevated deprivation score (OR 0.75, 95% CI 0.68-0.83), have known comorbidity (OR 0.78, 95% CI 0.63-0.97) or receive antiviral therapy ≤2 days before onset (OR 0.72, 95% CI 0.56-0.92). Increased case-severity during the second wave was not explained by changes in demographic, clinical or management characteristics. CONCLUSIONS: Monitoring changes in patient characteristics could help target interventions during multiple waves of COVID-19 or a future influenza pandemic. To understand and respond to changes in case-severity, surveillance is needed that includes additional factors such as admission thresholds and seasonal coinfections.


Subject(s)
Epidemics , Influenza A Virus, H1N1 Subtype , Influenza, Human , Adolescent , Adult , England/epidemiology , Epidemics/history , Female , History, 21st Century , Hospitalization , Humans , Influenza, Human/epidemiology , Male , Middle Aged , Minority Groups , Young Adult
19.
Euro Surveill ; 26(11)2021 03.
Article in English | MEDLINE | ID: covidwho-1143383

ABSTRACT

Between weeks 40 2020 and 8 2021, the World Health Organization European Region experienced a 99.8% reduction in sentinel influenza virus positive detections (33/25,606 tested; 0.1%) relative to an average of 14,966/39,407 (38.0%; p < 0.001) over the same time in the previous six seasons. COVID-19 pandemic public health and physical distancing measures may have extinguished the 2020/21 European seasonal influenza epidemic with just a few sporadic detections of all viral subtypes. This might possibly continue during the remainder of the influenza season.


Subject(s)
COVID-19 , Influenza, Human/epidemiology , Sentinel Surveillance , Europe , Humans , Influenza, Human/prevention & control , Pandemics , Physical Distancing , Seasons , World Health Organization
20.
Euro Surveill ; 25(46)2020 11.
Article in English | MEDLINE | ID: covidwho-937369

ABSTRACT

The COVID-19 pandemic negatively impacted the 2019/20 WHO European Region influenza surveillance. Compared with previous 4-year averages, antigenic and genetic characterisations decreased by 17% (3,140 vs 2,601) and 24% (4,474 vs 3,403). Of subtyped influenza A viruses, 56% (26,477/47,357) were A(H1)pdm09, 44% (20,880/47,357) A(H3). Of characterised B viruses, 98% (4,585/4,679) were B/Victoria. Considerable numbers of viruses antigenically differed from northern hemisphere vaccine components. In 2020/21, maintaining influenza virological surveillance, while supporting SARS-CoV-2 surveillance is crucial.


Subject(s)
Coronavirus Infections/epidemiology , Disease Notification/statistics & numerical data , Epidemiological Monitoring , Influenza A virus/isolation & purification , Influenza B virus/isolation & purification , Influenza, Human/epidemiology , Influenza, Human/virology , Antigens, Viral/genetics , Betacoronavirus , COVID-19 , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/isolation & purification , Influenza A Virus, H3N2 Subtype/genetics , Influenza A Virus, H3N2 Subtype/isolation & purification , Influenza A virus/genetics , Influenza B virus/genetics , Pandemics , Pneumonia, Viral , Population Surveillance , RNA, Viral/genetics , SARS-CoV-2 , Sequence Analysis, DNA
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