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1.
N Engl J Med ; 386(4): 340-350, 2022 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-35021002

RESUMO

BACKGROUND: Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), have been used since December 2020 in the United Kingdom. Real-world data have shown the vaccines to be highly effective against Covid-19 and related severe disease and death. Vaccine effectiveness may wane over time since the receipt of the second dose of the ChAdOx1-S (ChAdOx1 nCoV-19) and BNT162b2 vaccines. METHODS: We used a test-negative case-control design to estimate vaccine effectiveness against symptomatic Covid-19 and related hospitalization and death in England. Effectiveness of the ChAdOx1-S and BNT162b2 vaccines was assessed according to participant age and status with regard to coexisting conditions and over time since receipt of the second vaccine dose to investigate waning of effectiveness separately for the B.1.1.7 (alpha) and B.1.617.2 (delta) variants. RESULTS: Vaccine effectiveness against symptomatic Covid-19 with the delta variant peaked in the early weeks after receipt of the second dose and then decreased by 20 weeks to 44.3% (95% confidence interval [CI], 43.2 to 45.4) with the ChAdOx1-S vaccine and to 66.3% (95% CI, 65.7 to 66.9) with the BNT162b2 vaccine. Waning of vaccine effectiveness was greater in persons 65 years of age or older than in those 40 to 64 years of age. At 20 weeks or more after vaccination, vaccine effectiveness decreased less against both hospitalization, to 80.0% (95% CI, 76.8 to 82.7) with the ChAdOx1-S vaccine and 91.7% (95% CI, 90.2 to 93.0) with the BNT162b2 vaccine, and death, to 84.8% (95% CI, 76.2 to 90.3) and 91.9% (95% CI, 88.5 to 94.3), respectively. Greater waning in vaccine effectiveness against hospitalization was observed in persons 65 years of age or older in a clinically extremely vulnerable group and in persons 40 to 64 years of age with underlying medical conditions than in healthy adults. CONCLUSIONS: We observed limited waning in vaccine effectiveness against Covid-19-related hospitalization and death at 20 weeks or more after vaccination with two doses of the ChAdOx1-S or BNT162b2 vaccine. Waning was greater in older adults and in those in a clinical risk group.


Assuntos
Vacina BNT162 , COVID-19/prevenção & controle , ChAdOx1 nCoV-19 , Eficácia de Vacinas , Adolescente , Adulto , Fatores Etários , Idoso , COVID-19/mortalidade , COVID-19/virologia , Estudos de Casos e Controles , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Imunização Secundária , Imunogenicidade da Vacina , Masculino , Pessoa de Meia-Idade , Gravidade do Paciente , Fatores de Risco , SARS-CoV-2 , Fatores de Tempo , Reino Unido/epidemiologia
2.
N Engl J Med ; 386(16): 1532-1546, 2022 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-35249272

RESUMO

BACKGROUND: A rapid increase in coronavirus disease 2019 (Covid-19) cases due to the omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 in highly vaccinated populations has aroused concerns about the effectiveness of current vaccines. METHODS: We used a test-negative case-control design to estimate vaccine effectiveness against symptomatic disease caused by the omicron and delta (B.1.617.2) variants in England. Vaccine effectiveness was calculated after primary immunization with two doses of BNT162b2 (Pfizer-BioNTech), ChAdOx1 nCoV-19 (AstraZeneca), or mRNA-1273 (Moderna) vaccine and after a booster dose of BNT162b2, ChAdOx1 nCoV-19, or mRNA-1273. RESULTS: Between November 27, 2021, and January 12, 2022, a total of 886,774 eligible persons infected with the omicron variant, 204,154 eligible persons infected with the delta variant, and 1,572,621 eligible test-negative controls were identified. At all time points investigated and for all combinations of primary course and booster vaccines, vaccine effectiveness against symptomatic disease was higher for the delta variant than for the omicron variant. No effect against the omicron variant was noted from 20 weeks after two ChAdOx1 nCoV-19 doses, whereas vaccine effectiveness after two BNT162b2 doses was 65.5% (95% confidence interval [CI], 63.9 to 67.0) at 2 to 4 weeks, dropping to 8.8% (95% CI, 7.0 to 10.5) at 25 or more weeks. Among ChAdOx1 nCoV-19 primary course recipients, vaccine effectiveness increased to 62.4% (95% CI, 61.8 to 63.0) at 2 to 4 weeks after a BNT162b2 booster before decreasing to 39.6% (95% CI, 38.0 to 41.1) at 10 or more weeks. Among BNT162b2 primary course recipients, vaccine effectiveness increased to 67.2% (95% CI, 66.5 to 67.8) at 2 to 4 weeks after a BNT162b2 booster before declining to 45.7% (95% CI, 44.7 to 46.7) at 10 or more weeks. Vaccine effectiveness after a ChAdOx1 nCoV-19 primary course increased to 70.1% (95% CI, 69.5 to 70.7) at 2 to 4 weeks after an mRNA-1273 booster and decreased to 60.9% (95% CI, 59.7 to 62.1) at 5 to 9 weeks. After a BNT162b2 primary course, the mRNA-1273 booster increased vaccine effectiveness to 73.9% (95% CI, 73.1 to 74.6) at 2 to 4 weeks; vaccine effectiveness fell to 64.4% (95% CI, 62.6 to 66.1) at 5 to 9 weeks. CONCLUSIONS: Primary immunization with two doses of ChAdOx1 nCoV-19 or BNT162b2 vaccine provided limited protection against symptomatic disease caused by the omicron variant. A BNT162b2 or mRNA-1273 booster after either the ChAdOx1 nCoV-19 or BNT162b2 primary course substantially increased protection, but that protection waned over time. (Funded by the U.K. Health Security Agency.).


Assuntos
Vacinas contra COVID-19 , COVID-19 , Eficácia de Vacinas , Vacina de mRNA-1273 contra 2019-nCoV/uso terapêutico , Vacina BNT162/uso terapêutico , COVID-19/prevenção & controle , Vacinas contra COVID-19/uso terapêutico , Estudos de Casos e Controles , ChAdOx1 nCoV-19/uso terapêutico , Humanos , Imunização Secundária/efeitos adversos , SARS-CoV-2/genética
3.
Clin Infect Dis ; 78(2): 349-351, 2024 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-37758203

RESUMO

We estimated the risk of death from coronavirus disease 2019 in vaccinated compared with unvaccinated patients. The risk of death was reduced 44% after 1 dose of the Pfizer-BioNTech BNT162b2 vaccine, 55% after 1 dose of the Oxford-Astrazeneca ChAdOx1 vaccine, and 69% after 2 doses of the BNT162b2 vaccine. This is above the protection provided against infection.


Assuntos
Vacinas contra Adenovirus , COVID-19 , Vacinas , Adulto , Humanos , Adenoviridae/genética , Vacina BNT162 , Vacinas de mRNA , COVID-19/prevenção & controle , RNA Mensageiro
4.
N Engl J Med ; 385(7): 585-594, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34289274

RESUMO

BACKGROUND: The B.1.617.2 (delta) variant of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), has contributed to a surge in cases in India and has now been detected across the globe, including a notable increase in cases in the United Kingdom. The effectiveness of the BNT162b2 and ChAdOx1 nCoV-19 vaccines against this variant has been unclear. METHODS: We used a test-negative case-control design to estimate the effectiveness of vaccination against symptomatic disease caused by the delta variant or the predominant strain (B.1.1.7, or alpha variant) over the period that the delta variant began circulating. Variants were identified with the use of sequencing and on the basis of the spike (S) gene status. Data on all symptomatic sequenced cases of Covid-19 in England were used to estimate the proportion of cases with either variant according to the patients' vaccination status. RESULTS: Effectiveness after one dose of vaccine (BNT162b2 or ChAdOx1 nCoV-19) was notably lower among persons with the delta variant (30.7%; 95% confidence interval [CI], 25.2 to 35.7) than among those with the alpha variant (48.7%; 95% CI, 45.5 to 51.7); the results were similar for both vaccines. With the BNT162b2 vaccine, the effectiveness of two doses was 93.7% (95% CI, 91.6 to 95.3) among persons with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) among those with the delta variant. With the ChAdOx1 nCoV-19 vaccine, the effectiveness of two doses was 74.5% (95% CI, 68.4 to 79.4) among persons with the alpha variant and 67.0% (95% CI, 61.3 to 71.8) among those with the delta variant. CONCLUSIONS: Only modest differences in vaccine effectiveness were noted with the delta variant as compared with the alpha variant after the receipt of two vaccine doses. Absolute differences in vaccine effectiveness were more marked after the receipt of the first dose. This finding would support efforts to maximize vaccine uptake with two doses among vulnerable populations. (Funded by Public Health England.).


Assuntos
Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , SARS-CoV-2 , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/epidemiologia , COVID-19/virologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Reino Unido/epidemiologia , Potência de Vacina , Adulto Jovem
5.
Euro Surveill ; 29(3)2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38240057

RESUMO

Under International Health Regulations from 2005, a human infection caused by a novel influenza A virus variant is considered an event that has potential for high public health impact and is immediately notifiable to the World Health Organisation. We here describe the clinical, epidemiological and virological features of a confirmed human case of swine influenza A(H1N2)v in England detected through community respiratory virus surveillance. Swabbing and contact tracing helped refine public health risk assessment, following this unusual and unexpected finding.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana , Infecções por Orthomyxoviridae , Doenças dos Suínos , Animais , Humanos , Suínos , Vírus da Influenza A Subtipo H1N2 , Vírus da Influenza A Subtipo H1N1/genética , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/epidemiologia , Influenza Humana/diagnóstico , Influenza Humana/epidemiologia , Inglaterra/epidemiologia
6.
Emerg Infect Dis ; 29(1): 127-132, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36529456

RESUMO

A single SARS-CoV-2 vaccine dose reduces onward transmission from case-patients. We assessed the potential effects of receiving 2 doses on household transmission for case-patients in England and their household contacts. We used stratified Cox regression models to calculate hazard ratios (HRs) for contacts becoming secondary case-patients, comparing contacts of 2-dose vaccinated and unvaccinated index case-patients. We controlled for age, sex, and vaccination status of case-patients and contacts, as well as region, household composition, and relative socioeconomic condition based on household location. During the Alpha-dominant period, HRs were 0.19 (0.13-0.28) for contacts of 2-dose BNT162b2-vaccinated case-patients and 0.54 (0.41-0.69) for contacts of 2-dose Ch4dOx1-vaccinated case-patients; during the Delta-dominant period, HRs were higher, 0.74 (0.72-0.76) for BNT162b2 and 1.06 (1.04-1.08) for Ch4dOx1. Reduction of onward transmission was lower for index case-patients who tested positive ≥2 months after the second dose of either vaccine.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Humanos , Vacina BNT162 , SARS-CoV-2 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinação , Inglaterra/epidemiologia
7.
Epidemiol Infect ; 151: e58, 2023 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-36938806

RESUMO

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant (B.1.1.529) rapidly replaced Delta (B.1.617.2) to become dominant in England. Our study assessed differences in transmission between Omicron and Delta using two independent data sources and methods. Omicron and Delta cases were identified through genomic sequencing, genotyping and S-gene target failure in England from 5-11 December 2021. Secondary attack rates for named contacts were calculated in household and non-household settings using contact tracing data, while household clustering was identified using national surveillance data. Logistic regression models were applied to control for factors associated with transmission for both methods. For contact tracing data, higher secondary attack rates for Omicron vs. Delta were identified in households (15.0% vs. 10.8%) and non-households (8.2% vs. 3.7%). For both variants, in household settings, onward transmission was reduced from cases and named contacts who had three doses of vaccine compared to two, but this effect was less pronounced for Omicron (adjusted risk ratio, aRR 0.78 and 0.88) than Delta (aRR 0.62 and 0.68). In non-household settings, a similar reduction was observed only in contacts who had three doses vs. two doses for both Delta (aRR 0.51) and Omicron (aRR 0.76). For national surveillance data, the risk of household clustering, was increased 3.5-fold for Omicron compared to Delta (aRR 3.54 (3.29-3.81)). Our study identified increased risk of onward transmission of Omicron, consistent with its successful global displacement of Delta. We identified a reduced effectiveness of vaccination in lowering risk of transmission, a likely contributor for the rapid propagation of Omicron.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , Estudos de Coortes , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinação , Inglaterra/epidemiologia
8.
Euro Surveill ; 28(39)2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37768561

RESUMO

We investigated an outbreak of SARS-CoV-2 variant BA.2.86 in an East of England care home. We identified 45 infections (33 residents, 12 staff), among 38 residents and 66 staff. Twenty-nine of 43 PCR swabs were sequenced, all of which were variant BA.2.86. The attack rate among residents was 87%, 19 were symptomatic, and one was hospitalised. Twenty-four days after the outbreak started, no cases were still unwell. Among the 33 resident cases, 29 had been vaccinated 4 months earlier.

9.
J Infect Dis ; 226(5): 808-811, 2022 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-35184201

RESUMO

To investigate if the AY.4.2 sublineage of the SARS-CoV-2 delta variant is associated with hospitalization and mortality risks that differ from non-AY.4.2 delta risks, we performed a retrospective cohort study of sequencing-confirmed COVID-19 cases in England based on linkage of routine health care datasets. Using stratified Cox regression, we estimated adjusted hazard ratios (aHR) of hospital admission (aHR = 0.85; 95% confidence interval [CI], .77-.94), hospital admission or emergency care attendance (aHR = 0.87; 95% CI, .81-.94), and COVID-19 mortality (aHR = 0.85; 95% CI, .71-1.03). The results indicate that the risks of hospitalization and mortality are similar or lower for AY.4.2 compared to cases with other delta sublineages.


Assuntos
COVID-19 , SARS-CoV-2 , Hospitalização , Humanos , Estudos Retrospectivos
10.
Lancet ; 398(10316): 2084-2092, 2021 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-34741816

RESUMO

BACKGROUND: Human papillomavirus (HPV) immunisation with a bivalent vaccine (Cervarix) was introduced in England, UK, in Sept 1, 2008: routine vaccination was offered to girls aged 12-13 years with a catch-up programme for females aged 14-18 years in 2008-10. We quantified the early effect of this immunisation programme on cervical cancer and cervical carcinoma in situ, namely grade 3 cervical intraepithelial neoplasia (CIN3), registrations. METHODS: In this observational study, we used an extension of the age-period-cohort Poisson model to estimate the relative risk of cervical cancer in three vaccinated cohorts compared with earlier cohorts that were not eligible for HPV vaccination. Data from a population-based cancer registry were extracted on Jan 26, 2021, and were assessed for diagnoses of cervical cancer and CIN3 from Jan 1, 2006 to June 30, 2019 in women aged 20-64 years and who were a resident in England. We used three vaccinated cohorts to account for differences in the school year in which the vaccine was offered and its national coverage. Adjustment for confounding was made using information on changes in cervical screening policy and historical events that affected cervical cancer incidence. Results were compared across models with different adjustments for confounders. FINDINGS: We used data from a total of 13·7 million-years of follow-up of women aged 20 years to younger than 30 years. The estimated relative reduction in cervical cancer rates by age at vaccine offer were 34% (95% CI 25-41) for age 16-18 years (school year 12-13), 62% (52-71) for age 14-16 years (school year 10-11), and 87% (72-94) for age 12-13 years (school year 8), compared with the reference unvaccinated cohort. The corresponding risk reductions for CIN3 were 39% (95% CI 36-41) for those offered at age 16-18 years, 75% (72-77) for age 14-16 years, and 97% (96-98) for age 12-13 years. These results remained similar across models. We estimated that by June 30, 2019 there had been 448 (339-556) fewer than expected cervical cancers and 17 235 (15 919-18 552) fewer than expected cases of CIN3 in vaccinated cohorts in England. INTERPRETATION: We observed a substantial reduction in cervical cancer and incidence of CIN3 in young women after the introduction of the HPV immunisation programme in England, especially in individuals who were offered the vaccine at age 12-13 years. The HPV immunisation programme has successfully almost eliminated cervical cancer in women born since Sept 1, 1995. FUNDING: Cancer Research UK.


Assuntos
Detecção Precoce de Câncer , Incidência , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Displasia do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Adolescente , Adulto , Criança , Inglaterra/epidemiologia , Feminino , Humanos , Imunização , Pessoa de Meia-Idade , Sistema de Registros , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/virologia , Vacinação , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/virologia
11.
Lancet ; 397(10286): 1725-1735, 2021 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-33901423

RESUMO

BACKGROUND: BNT162b2 mRNA and ChAdOx1 nCOV-19 adenoviral vector vaccines have been rapidly rolled out in the UK from December, 2020. We aimed to determine the factors associated with vaccine coverage for both vaccines and documented the vaccine effectiveness of the BNT162b2 mRNA vaccine in a cohort of health-care workers undergoing regular asymptomatic testing. METHODS: The SIREN study is a prospective cohort study among staff (aged ≥18 years) working in publicly-funded hospitals in the UK. Participants were assigned into either the positive cohort (antibody positive or history of infection [indicated by previous positivity of antibody or PCR tests]) or the negative cohort (antibody negative with no previous positive test) at the beginning of the follow-up period. Baseline risk factors were collected at enrolment, symptom status was collected every 2 weeks, and vaccination status was collected through linkage to the National Immunisations Management System and questionnaires. Participants had fortnightly asymptomatic SARS-CoV-2 PCR testing and monthly antibody testing, and all tests (including symptomatic testing) outside SIREN were captured. Data cutoff for this analysis was Feb 5, 2021. The follow-up period was Dec 7, 2020, to Feb 5, 2021. The primary outcomes were vaccinated participants (binary ever vacinated variable; indicated by at least one vaccine dose recorded by at least one of the two vaccination data sources) for the vaccine coverage analysis and SARS-CoV-2 infection confirmed by a PCR test for the vaccine effectiveness analysis. We did a mixed-effect logistic regression analysis to identify factors associated with vaccine coverage. We used a piecewise exponential hazard mixed-effects model (shared frailty-type model) using a Poisson distribution to calculate hazard ratios to compare time-to-infection in unvaccinated and vaccinated participants and estimate the impact of the BNT162b2 vaccine on all PCR-positive infections (asymptomatic and symptomatic). This study is registered with ISRCTN, number ISRCTN11041050, and is ongoing. FINDINGS: 23 324 participants from 104 sites (all in England) met the inclusion criteria for this analysis and were enrolled. Included participants had a median age of 46·1 years (IQR 36·0-54·1) and 19 692 (84%) were female; 8203 (35%) were assigned to the positive cohort at the start of the analysis period, and 15 121 (65%) assigned to the negative cohort. Total follow-up time was 2 calendar months and 1 106 905 person-days (396 318 vaccinated and 710 587 unvaccinated). Vaccine coverage was 89% on Feb 5, 2021, 94% of whom had BNT162b2 vaccine. Significantly lower coverage was associated with previous infection, gender, age, ethnicity, job role, and Index of Multiple Deprivation score. During follow-up, there were 977 new infections in the unvaccinated cohort, an incidence density of 14 infections per 10 000 person-days; the vaccinated cohort had 71 new infections 21 days or more after their first dose (incidence density of eight infections per 10 000 person-days) and nine infections 7 days after the second dose (incidence density four infections per 10 000 person-days). In the unvaccinated cohort, 543 (56%) participants had typical COVID-19 symptoms and 140 (14%) were asymptomatic on or 14 days before their PCR positive test date, compared with 29 (36%) with typical COVID-19 symptoms and 15 (19%) asymptomatic in the vaccinated cohort. A single dose of BNT162b2 vaccine showed vaccine effectiveness of 70% (95% CI 55-85) 21 days after first dose and 85% (74-96) 7 days after two doses in the study population. INTERPRETATION: Our findings show that the BNT162b2 vaccine can prevent both symptomatic and asymptomatic infection in working-age adults. This cohort was vaccinated when the dominant variant in circulation was B1.1.7 and shows effectiveness against this variant. FUNDING: Public Health England, UK Department of Health and Social Care, and the National Institute for Health Research.


Assuntos
Vacinas contra COVID-19/provisão & distribuição , Pessoal de Saúde , Doenças Profissionais/prevenção & controle , Exposição Ocupacional/prevenção & controle , RNA Mensageiro , Vacina BNT162 , Vacinas contra COVID-19/administração & dosagem , Estudos de Coortes , Inglaterra , Humanos , Estudos Prospectivos , Resultado do Tratamento
12.
Age Ageing ; 51(5)2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35596946

RESUMO

INTRODUCTION: residents of long-term care facilities (LTCFs) are at high risk of adverse outcomes from SARS-CoV-2. We aimed to estimate the vaccine effectiveness (VE) of one and two doses of BNT162b2 and ChAdOx-1 against SARS CoV-2 infection and COVID-19-related death in residents of LTCFs. METHODS: this observational study used testing, vaccination and mortality data for LTCF residents aged ≥ 65 years who were regularly tested regardless of symptoms from 8 December 2020 to 30 September 2021 in England. Adjusted VE, calculated as one minus adjusted hazard ratio, was estimated using time-varying Cox proportional hazards models for infection and death within 28 days of positive test result. Vaccine status was defined by receipt of one or two doses of vaccine and assessed over a range of intervals. RESULTS: of 197,885 LTCF residents, 47,087 (23.8%) had a positive test and 11,329 (5.8%) died within 28 days of a positive test during the study period. Relative to unvaccinated individuals, VE for infection was highest for ChAdOx-1 at 61% (40-74%) at 1-4 weeks and for BNT162b2 at 69% (52-80%) at 11-15 weeks following the second dose. Against death, VE was highest for ChAdOx-1 at 83% (58-94%) at 1-4 weeks and for BNT162b2 at 91% (75-97%) at 11-15 weeks following second dose. CONCLUSIONS: compared with unvaccinated residents, vaccination with one dose of BNT162b2 or ChAdOx-1 provided moderate protection against infection and death in residents of LTCFs. Protection against death improved after two doses. However, some waning of protection over time was noted.


Assuntos
COVID-19 , SARS-CoV-2 , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Inglaterra/epidemiologia , Humanos , Assistência de Longa Duração , Modelos de Riscos Proporcionais
13.
Euro Surveill ; 27(15)2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35426357

RESUMO

BackgroundHouseholds appear to be the highest risk setting for COVID-19 transmission. Large household transmission studies in the early stages of the pandemic in Asia reported secondary attack rates ranging from 5 to 30%.AimWe aimed to investigate the transmission dynamics of COVID-19 in household and community settings in the UK.MethodsA prospective case-ascertained study design based on the World Health Organization FFX protocol was undertaken in the UK following the detection of the first case in late January 2020. Household contacts of cases were followed using enhanced surveillance forms to establish whether they developed symptoms of COVID-19, became confirmed cases and their outcomes. We estimated household secondary attack rates (SAR), serial intervals and individual and household basic reproduction numbers. The incubation period was estimated using known point source exposures that resulted in secondary cases.ResultsWe included 233 households with two or more people with 472 contacts. The overall household SAR was 37% (95% CI: 31-43%) with a mean serial interval of 4.67 days, an R0 of 1.85 and a household reproduction number of 2.33. SAR were lower in larger households and highest when the primary case was younger than 18 years. We estimated a mean incubation period of around 4.5 days.ConclusionsRates of COVID-19 household transmission were high in the UK for ages above and under 18 years, emphasising the need for preventative measures in this setting. This study highlights the importance of the FFX protocol in providing early insights on transmission dynamics.


Assuntos
COVID-19 , Adolescente , Características da Família , Humanos , Pandemias , SARS-CoV-2 , Reino Unido/epidemiologia
14.
Epidemiol Infect ; 149: e248, 2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34749838

RESUMO

This study describes the development of a pilot sentinel school absence syndromic surveillance system. Using data from a sample of schools in England the capability of this system to monitor the impact of disease on school absences in school-aged children is shown, using the coronavirus disease 2019 (COVID-19) pandemic period as an example. Data were obtained from an online app service used by schools and parents to report their children absent, including reasons/symptoms relating to absence. For 2019 and 2020, data were aggregated into daily counts of 'total' and 'cough' absence reports. There was a large increase in the number of absence reports in March 2020 compared to March 2019, corresponding to the first wave of the COVID-19 pandemic in England. Absence numbers then fell rapidly and remained low from late March 2020 until August 2020, while lockdown was in place in England. Compared to 2019, there was a large increase in the number of absence reports in September 2020 when schools re-opened in England, although the peak number of absences was smaller than in March 2020. This information can help provide context around the absence levels in schools associated with COVID-19. Also, the system has the potential for further development to monitor the impact of other conditions on school absence, e.g. gastrointestinal infections.


Assuntos
Absenteísmo , COVID-19/epidemiologia , Surtos de Doenças/prevenção & controle , Monitoramento Epidemiológico , Vigilância de Evento Sentinela , Criança , Controle de Doenças Transmissíveis , Inglaterra/epidemiologia , Humanos , Masculino , Pandemias , SARS-CoV-2 , Instituições Acadêmicas , Estudantes/estatística & dados numéricos
15.
Euro Surveill ; 26(27)2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34240699

RESUMO

We investigated a COVID-19 outbreak of the SARS-CoV-2 Delta variant of concern in a London care home, where 8/21 residents and 14/21 staff had received a single dose of Vaxzevria (ChAdOx1-S; AstraZeneca) vaccine. We identified 24 SARS-CoV-2 infections (16 residents, 8 staff) among 40 individuals (19 residents, 21 staff); four (3 residents, 1 staff) were hospitalised, and none died. The attack rate after one vaccine dose was 35.7% (5/14) for staff and 81.3% (13/16) for residents.


Assuntos
COVID-19 , SARS-CoV-2 , Vacinas contra COVID-19 , Surtos de Doenças , Inglaterra , Humanos , Londres/epidemiologia , Vacinação
16.
Euro Surveill ; 25(28)2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32700669

RESUMO

England has experienced one of the highest excess in all-cause mortality in Europe during the current COVID-19 pandemic. As COVID-19 emerged, the excess in all-cause mortality rapidly increased, starting in March 2020. The excess observed during the pandemic was higher than excesses noted in the past 5 years. It concerned all regions and all age groups, except the 0-14 year olds, but was more pronounced in the London region and in those aged ≥ 85 years.


Assuntos
Betacoronavirus , Infecções por Coronavirus/mortalidade , Pneumonia Viral/mortalidade , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Algoritmos , COVID-19 , Causas de Morte , Inglaterra/epidemiologia , Humanos , Pessoa de Meia-Idade , Pandemias , Distribuição de Poisson , SARS-CoV-2 , Adulto Jovem
17.
Euro Surveill ; 25(32)2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32794447

RESUMO

Severe acute respiratory syndrome coronavirus 2 viral load in the upper respiratory tract peaks around symptom onset and infectious virus persists for 10 days in mild-to-moderate coronavirus disease (n = 324 samples analysed). RT-PCR cycle threshold (Ct) values correlate strongly with cultivable virus. Probability of culturing virus declines to 8% in samples with Ct > 35 and to 6% 10 days after onset; it is similar in asymptomatic and symptomatic persons. Asymptomatic persons represent a source of transmissible virus.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/diagnóstico , Coronavirus/genética , Coronavirus/patogenicidade , Pandemias , Pneumonia Viral/diagnóstico , RNA Viral/genética , Eliminação de Partículas Virais/fisiologia , Infecções Assintomáticas , Betacoronavirus , COVID-19 , Teste para COVID-19 , Técnicas de Laboratório Clínico , Coronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/virologia , Inglaterra/epidemiologia , Humanos , Pneumonia Viral/epidemiologia , Pneumonia Viral/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2 , Testes Sorológicos , Carga Viral , Eliminação de Partículas Virais/genética
19.
Scand J Public Health ; 43(8): 796-801, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26261189

RESUMO

BACKGROUND: The upturn of life expectancy in Central and Eastern Europe in the 1990s, after a period of stagnation or even decline, is one of the main events in European population history of the late 20th century, but has not been satisfactorily explained. DATA AND METHODS: Turning points in total and cause-specific mortality in the Czech Republic, Bulgaria, Hungary, Poland, Romania and Slovakia were determined using joinpoint regression. Changes in life expectancy in the 10 years following country-specific turning points were decomposed by age and cause of death using Arriaga's method. RESULTS: Among men, the turning points for all-cause mortality coincided with those for ischaemic heart disease in all six countries, and sometimes also with those for liver cirrhosis, road traffic accidents and lung cancer. Among women, the pattern was more diffuse. In the 10 years since the turning point for all-cause mortality, life expectancy increased by around four years for men and three years for women in most countries. Declines in mortality from cardiovascular disease explain between a third and a half of the increase in life expectancy in all countries, but beyond this the contributing causes of death often varied considerably. CONCLUSIONS: Although the upturn of life expectancy in Central and Eastern Europe started at different points in time, improvements in prevention and/or treatment of ischaemic heart disease appear to have played a role in all six countries. Other factors, such as changes in alcohol consumption and road traffic safety, have, however, also made important contributions in some countries.


Assuntos
Expectativa de Vida/tendências , Acidentes de Trânsito/prevenção & controle , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Causas de Morte/tendências , Europa (Continente)/epidemiologia , Europa Oriental/epidemiologia , Feminino , Humanos , Masculino
20.
Hum Vaccin Immunother ; 20(1): 2311969, 2024 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38299507

RESUMO

Acute disseminated encephalomyelitis (ADEM) has been identified as an Adverse Event of Special Interest in the COVID-19 vaccine programme due to its long-standing temporal association with a wide range of other vaccines. Case reports of ADEM shortly following COVID-19 vaccination have now been documented. There were 217 ADEM admissions in 215 individuals in the period 8th December 2020 to 31st March 2023. An increased risk of ADEM following the first dose of ChAdOx1 vaccine was observed (relative incidence (RI) = 3.13, 95% Confidence Interval (CI) [1.56-6.25]) with a vaccine attributable risk of 0.39 per million doses. When doses 1 and 2 were combined this increased risk remained just significant (1.96 [95%CI 1.01-3.82]). No significant increased risk was observed with any other vaccine or dose. This small, elevated risk after the first dose of ChAdOx1-S vaccine demonstrates how large national electronic datasets can be used to identify very rare risks and provides reassurance that any risk of ADEM following the ChAdOx1-S COVID-19 vaccination is extremely small. Given the rarity of this risk, further studies in settings with access to data on large populations should be carried out to verify these findings.


Assuntos
COVID-19 , Encefalomielite Aguda Disseminada , Vacinas , Humanos , Encefalomielite Aguda Disseminada/induzido quimicamente , Encefalomielite Aguda Disseminada/epidemiologia , Vacinas contra COVID-19/efeitos adversos , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/complicações , Vacinas/efeitos adversos , Vacinação/efeitos adversos , ChAdOx1 nCoV-19 , Inglaterra/epidemiologia
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