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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336247

ABSTRACT

Objective To analyse the impact on hospital admissions for COVID-19 of large-scale, voluntary, public open access rapid testing for SARS-CoV-2 antigen in Liverpool (UK) between 6 th November 2020 and 2 nd January 2021. Design Synthetic control analysis comparing hospital admissions for small areas in the intervention population to a group of control areas weighted to be similar in terms of prior COVID-19 hospital admission rates and socio-demographic factors. Intervention COVID-SMART (Systematic Meaningful Asymptomatic Repeated Testing), a national pilot of large-scale, voluntary rapid antigen testing for people without symptoms of COVID-19 living or working in the City of Liverpool, deployed with the assistance of the British Army from the 6 th November 2020 in an unvaccinated population. This pilot informed the UK roll-out of SARS-CoV-2 antigen rapid testing, and similar policies internationally. Main outcome measure Weekly COVID-19 hospital admissions for neighbourhoods in England. Results The intensive introduction of COVID-SMART community testing was associated with a 43% (95% confidence interval: 29% to 57%) reduction in COVID-19 hospital admissions in Liverpool compared to control areas for the initial period of intensive testing with military assistance in national lockdown from 6 th November to 3 rd December 2020. A 25% (11% to 35%) reduction was estimated across the overall intervention period (6 th November 2020 to 2 nd January 2021), involving fewer testing centres, before England’s national roll-out of community testing, after adjusting for regional differences in Tiers of COVID-19 restrictions from 3 rd December 2020 to 2 nd January 2021. Conclusions The world’s first voluntary, city-wide SARS-CoV-2 rapid antigen testing pilot in Liverpool substantially reduced COVID-19 hospital admissions. Large scale asymptomatic rapid testing for SARS-CoV-2 can help reduce transmission and prevent hospital admissions. Summary box What is already known on this topic – Previous studies on managing the spread of SARS-CoV-2 have identified asymptomatic transmission as significant challenges for controlling the pandemic. – Along with non-pharmaceutical measures, many countries rolled out population-based asymptomatic testing programmes to further limit transmission. – Evidence is required on whether large scale voluntary testing of communities for COVID-19 reduces severe disease, by breaking chains of transmission. What this study adds – The findings of this study suggest that large scale rapid antigen testing of communities for SARS-CoV-2, within an agile local public health campaign, can reduce transmission and prevent hospital admissions. – The results indicate that policy makers should integrate such testing into comprehensive, local public health programmes targeting high risk groups, supporting those required to isolate and adapting promptly to prevailing biological, behavioural and environmental circumstances.

2.
BMJ Open ; 12(4): e054101, 2022 04 12.
Article in English | MEDLINE | ID: covidwho-1788960

ABSTRACT

OBJECTIVES: To analyse the impact on SARS-CoV-2 transmission of tier 3 restrictions introduced in October and December 2020 in England, compared with tier 2 restrictions. We further investigate whether these effects varied between small areas by deprivation. DESIGN: Synthetic control analysis. SETTING: We identified areas introducing tier 3 restrictions in October and December, constructed a synthetic control group of places under tier 2 restrictions and compared changes in weekly infections over a 4-week period. Using interaction analysis, we estimated whether this effect varied by deprivation and the prevalence of a new variant (B.1.1.7). INTERVENTIONS: In both October and December, no indoor between-household mixing was permitted in either tier 2 or 3. In October, no between-household mixing was permitted in private gardens and pubs and restaurants remained open only if they served a 'substantial meal' in tier 3, while in tier 2 meeting with up to six people in private gardens were allowed and all pubs and restaurants remained open. In December, in tier 3, pubs and restaurants were closed, while in tier 2, only those serving food remained open. The differences in restrictions between tier 2 and 3 on meeting outside remained the same as in October. MAIN OUTCOME MEASURE: Weekly reported cases adjusted for changing case detection rates for neighbourhoods in England. RESULTS: Introducing tier 3 restrictions in October and December was associated with a 14% (95% CI 10% to 19%) and 20% (95% CI 13% to 29%) reduction in infections, respectively, compared with the rates expected with tier 2 restrictions only. The effects were similar across levels of deprivation and by the prevalence of the new variant. CONCLUSIONS: Compared with tier 2 restrictions, additional restrictions in tier 3 areas in England had a moderate effect on transmission, which did not appear to increase socioeconomic inequalities in COVID-19 cases.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , COVID-19/prevention & control , Family Characteristics , Humans , Restaurants
3.
BMC Infect Dis ; 22(1): 270, 2022 Mar 20.
Article in English | MEDLINE | ID: covidwho-1745481

ABSTRACT

BACKGROUND: From January to May 2021 the alpha variant (B.1.1.7) of SARS-CoV-2 was the most commonly detected variant in the UK. Following this, the Delta variant (B.1.617.2) then became the predominant variant. The UK COVID-19 vaccination programme started on 8th December 2020. Prior to the Delta variant, most vaccine effectiveness studies focused on the alpha variant. We therefore aimed to estimate the effectiveness of the BNT162b2 (Pfizer-BioNTech) and the ChAdOx1 nCoV-19 (Oxford-AstraZeneca) vaccines in preventing symptomatic and asymptomatic infection with respect to the Delta variant in a UK setting. METHODS: We used anonymised public health record data linked to infection data (PCR) using the Combined Intelligence for Population Health Action resource. We then constructed an SIR epidemic model to explain SARS-CoV-2 infection data across the Cheshire and Merseyside region of the UK. Vaccines were assumed to be effective after 21 days for 1 dose and 14 days for 2 doses. RESULTS: We determined that the effectiveness of the Oxford-AstraZeneca vaccine in reducing susceptibility to infection is 39% (95% credible interval [34, 43]) and 64% (95% credible interval [61, 67]) for a single dose and a double dose respectively. For the Pfizer-BioNTech vaccine, the effectiveness is 20% (95% credible interval [10, 28]) and 84% (95% credible interval [82, 86]) for a single-dose and a double dose respectively. CONCLUSION: Vaccine effectiveness for reducing susceptibility to SARS-CoV-2 infection shows noticeable improvement after receiving two doses of either vaccine. Findings also suggest that a full course of the Pfizer-BioNTech provides the optimal protection against infection with the Delta variant. This reinforces the need to complete the full course programme to maximise individual protection and reduce transmission.


Subject(s)
COVID-19 , Viral Vaccines , COVID-19/prevention & control , COVID-19 Vaccines , Humans , SARS-CoV-2/genetics
4.
The Lancet ; 398, 2021.
Article in English | ProQuest Central | ID: covidwho-1537173

ABSTRACT

Background In 2020, a second wave of COVID-19 cases unevenly affected places in England, and different levels of tiered restrictions were introduced in different parts of the country. Previous research has examined the impact of national lockdowns on transmission. We aimed to examine the differences in the effect of localised restrictions on COVID-19 cases and how these differences varied by deprivation. Methods We examined the transmission impact of tier 3 restrictions using data on weekly reported COVID-19 cases, adjusted for case-detection rates for 7201 neighbourhoods in England. We identified areas that entered tier 3 restrictions in October and December, 2020, constructed a synthetic control group of places under tier 2 restrictions, and compared changes in weekly infections over a 4-week period. Sufficiently granular data on deaths were not available to investigate excess mortality. We analysed whether this effect varied by level of deprivation and the prevalence of a new variant (B.1.1.7), by stratifying the synthetic control weighting by subgroups and then including an interaction term between subgroup and intervention in the regression model. We used the English Indices of Multiple Deprivation and its tertiles in the stratification to measure deprivation. We tested the spatial spillover effects excluding tier 2 areas within 20 km of tier 3 areas. Ethics approval was not needed. Findings The introduction of tier 3 restrictions was associated with a reduction in infections of 14% (95% CI 10–19) in October and of 20% (13–29) in December, or with a reduction in absolute number of total infections of 3536 (95% CI 2880–4192) in October and of 92 732 (49 776–135 688) in December, compared with what would have been expected under tier 2 restrictions. The effects were similar across levels of deprivation and by the prevalence of the new variant. We found smaller effects with high non-significant p values when excluding boundary areas. Interpretation Compared to tier 2 restrictions, restrictions on hospitality and meeting outdoors in tier 3 areas had a moderate effect on transmission and these restrictions did not appear to increase inequalities in COVID-19 cases. Limitations include a lack of specificity as to which of the main restrictions contributed to this effect, potentially biases from the crude measure of case-detection rates applied, and the lack of controls for individual or household characteristics in this ecological analysis. Funding National Institute for Health Research (NIHR).

5.
Journal of Epidemiology and Community Health ; 75(Suppl 1):A1, 2021.
Article in English | ProQuest Central | ID: covidwho-1394140

ABSTRACT

BackgroundIn 2020, a second wave of COVID-19 cases unevenly affected places in England leading to the introduction of a tiered system of controls with different geographical areas subject to different levels of restrictions. Whilst previous research has examined the impact of national lockdowns on transmission, there has been limited research examining the marginal effect of differences in localised restrictions or how these effects vary between socioeconomic contexts. We therefore examined how Tier 3 restrictions in England implemented between October-December 2020, which included additional restrictions on the hospitality sector and people meeting outdoors affected COVID-19 case rates, compared to Tier 2 restrictions, and how these effects varied by level of deprivation.MethodsWe used data on weekly reported COVID-19 cases for 7201 neighbourhoods in England and adjusted these for changing case-detection rates to provide an estimate of weekly SARS-CoV-2 infections in each neighbourhood. We identified those areas that entered Tier 3 restrictions at two time points in October and December, and constructed a synthetic control group of similar places that had entered Tier 2 restrictions, using calibration weights to match them on a wide range of covariates that may influence transmission. We then compared the change in weekly infections between those entering Tier 3 to the synthetic control group to estimate the proportional reduction of cases resulting from Tier 3 restrictions compared to Tier 2 restrictions, over a 4-week period. We further used interaction analysis to estimate whether this effect differed based on the level of socioeconomic deprivation in each neighbourhood and whether effects were modified by the prevalence of a new more infectious variant of SARS-CoV-2 (B.1.1.7) in each area.ResultsThe introduction of Tier 3 restrictions in October and December was associated with a 14% (95% CI 10% to 19%) and 20% (95% CI 13% to 29%) reduction in infections respectively, compared to the rates expected if only Tier 2 restrictions had been in place in those areas. We found that effects were similar across levels of deprivation and limited evidence that Tier 3 restrictions had a greater effect in areas where the new more infectious variant was more prevalent.DiscussionCompared to Tier 2 restrictions, additional restrictions on hospitality and meeting outdoors introduced in Tier 3 areas in England had a moderate effect on transmission and these restrictions did not appear to increase inequalities.

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