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Early effectiveness of COVID-19 vaccination with BNT162b2 mRNA vaccine and ChAdOx1 adenovirus vector vaccine on symptomatic disease, hospitalisations and mortality in older adults in England

TL;DR: In this article, the real-world effectiveness of the Pfizer/BioNTech BNT162b2 vaccine and Astrazeneca ChAdOx1 vaccine against Confirmed COVID-19, hospitalisations and deaths was estimated relative to the baseline post-vaccination period.
Abstract: Objectives To estimate the real-world effectiveness of the Pfizer/BioNTech BNT162b2 vaccine and Astrazeneca ChAdOx1 vaccine against Confirmed COVID-19, hospitalisations and deaths. To estimate effectiveness on the UK variant of concern. Design Test negative case control design Setting Community COVID-19 PCR testing in England Participants All adults in England aged 70 years and older (over 7.5 million). All COVID-19 testing in the community among eligible individuals who reported symptoms between 8th December 2020 and 19th February 2021 was included in the analysis. Interventions One and two doses of BNT162b2 vaccine. One dose of ChAdOx1 vaccine. Main outcome measures Symptomatic PCR confirmed SARS-CoV-2 infection, hospitalisations and deaths with COVID-19. Results Individuals aged >=80 years vaccinated with BNT162b2 prior to 4th January, had a higher odds of testing positive in the first 9 days after vaccination (odds ratio up to 1.48, 95%CI 1.23-1.77), indicating that those initially targeted had a higher underlying risk of infection. Vaccine effectiveness was therefore estimated relative to the baseline post-vaccination period. Vaccine effects were noted from 10-13 days after vaccination, reaching an effectiveness of 70% (95% CI 59-78%) from 28-34 days, then plateauing. From 14 days after the second dose a vaccine effectiveness of 89% (95%CI: 85-93%) was seen. Individuals aged >=70 years vaccinated from 4th January had a similar underlying risk of COVID-19 to unvaccinated individuals. With BNT162b2, vaccine effectiveness reached 61% (95%CI 51-69%) from 28-34 days after vaccination then plateaued. With the ChAdOx1 vaccine, vaccine effects were seen from 14-20 days after vaccination reaching an effectiveness of 60% (95%CI 41-73%) from 28-34 days and further increasing to 73% (95%CI 27-90%) from day 35 onwards. On top of the protection against symptomatic disease, cases who had been vaccinated with one dose of BNT162b2 had an additional 43% (95%CI 33-52%) lower risk of emergency hospitalisation and an additional 51% (95%CI 37-62%) lower risk of death. Cases who had been vaccinated with one dose of ChAdOx1 had an additional 37% (95% CI 3-59%) lower risk of emergency hospitalisation. There was insufficient follow-up to assess the effect of ChAdOx1 on mortality due to the later rollout of this vaccine. Combined with the effect against symptomatic disease, this indicates that a single dose of either vaccine is approximately 80% effective at preventing hospitalisation and a single dose of BNT162b2 is 85% effective at preventing death with COVID-19. Conclusion Vaccination with either a single dose of BNT162b2 or ChAdOx1 COVID-19 vaccination was associated with a significant reduction in symptomatic SARS-CoV2 positive cases in older adults with even greater protection against severe disease. Both vaccines show similar effects. Protection was maintained for the duration of follow-up (>6 weeks). A second dose of BNT162b2 provides further protection against symptomatic disease but second doses of ChAdOx1 have not yet been rolled out in England. There is a clear effect of the vaccines against the UK variant of concern.

Summary (2 min read)

Introduction

  • On the 8 th December 2020 the UK became the first country to implement a COVID-19 vaccination programme following the approval of the Pfizer-BioNtech messenger RNA (mRNA) vaccine, BNT162b2, for emergency use.
  • The burden of COVID-19 in the UK remains high and early evidence on the effectiveness of vaccines is essential for informing policy decisions on the ongoing rollout of the programme and the use of other non-pharmaceutical interventions.
  • (2) During these first few weeks of the programme, the priority groups for vaccination included: (i) residents in a care home for older adults and their carers; and (ii) all those 80 years of age and over and frontline health and social care workers.
  • Interim results from phase 3 clinical trials have found the BNT162b2 and ChAdOx1 vaccines to be highly effective using a two-dose schedule with a target interval of 3 weeks and 4 weeks respectively between doses.
  • (10, 11) The variant is characterised by 23 mutations, including mutations to genes encoding the spike protein, the target in the two vaccines currently in use, as well as the majority of vaccine candidates.

Covariates

  • These include demographic factors, such as age, gender, index of multiple deprivation and ethnicity; geography and period (incidence of COVID-19 varied by region and by week over the study period, as did vaccine rollout); and care home status, care homes have been high exposure settings during the course of the pandemic.
  • Age, gender, DOB, ethnicity and address were extracted from the testing data and the NIMS.
  • Addresses were used to determine index of multiple deprivation quintile and were also linked to Care Quality Commission (CQC) registered care homes using the Unique Property Reference Number.

Statistical methods

  • Logistic regression was used to estimate the odds of vaccination in PCR confirmed cases compared to those testing negative .
  • Individuals contributed a maximum of three randomly chosen negative results in the follow-up period after excluding any taken within three weeks before a positive test result, or after a positive result, which are more likely to be false negatives, or taken within <7 days of a previous negative sample, again, because these could represent a single illness episode.
  • Proportional hazards survival analyses were also conducted for these outcomes, adjusting for age, care home status, gender and period.
  • Ethics and Governance Group and was found to be fully compliant with all regulatory requirements.

Ethics

  • As no regulatory issues were identified, and ethical review is not a requirement for this type of work, it was decided that a full ethical review would not be necessary.
  • Differences in characteristics in linked and unlinked tests are shown in supplementary table 1.
  • During the first few days after vaccination (before an immune response would be anticipated), vaccinated individuals had a higher odds of testing positive, suggesting that vaccination was being targeted at those at higher risk of disease.
  • A stratified approach was therefore considered more appropriate for the primary analysis.

Vaccine coverage by vaccine brand at

  • This was due to confounding by age and care home status, likely because few care home residents were vaccinated in the early period and this period was restricted to a smaller age group (>=80 years).
  • When using the comparison to the 4-9 day period to account for differences in baseline risk in those vaccinated, the results are similar with and without SGTF.

Discussion

  • This study provides the first real world evidence of COVID-19 vaccine effectiveness against symptomatic COVID-19 in older people in the UK.
  • (4, 23) This effect appears to lessen as roll-out vaccination programme progresses suggesting that access to vaccine was initially focussed on those at higher risk, although this bias may still affect the longer follow-up periods (to which those vaccinated earliest will contribute) more than the earlier follow-up periods.
  • Dagan et al found a vaccine effectiveness against symptomatic disease of 57% in the 14-20 day period and 66% in the 21-27 day period which is similar to their estimates.
  • The initial phase 3 trial found a two-dose efficacy against symptomatic disease of 70.4% (all ages).(.
  • Failure to exclude those with past infection because of low testing rates in wave 1 is another possibility.

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Content maybe subject to copyright    Report

Early effectiveness of COVID-19 vaccination with BNT162b2
mRNA vaccine and ChAdOx1 adenovirus vector vaccine on
symptomatic disease, hospitalisations and mortality in older
adults in England
Jamie Lopez Bernal
1,2,3
, Nick Andrews
1,2
, Charlotte Gower
1
, Julia Stowe
1
, Chris Robertson
4
, Elise
Tessier
1
, Ruth Simmons,
1
Simon Cottrell
5
, Richard Roberts
5
, Mark ODoherty
6
, Kevin Brown
1
, Claire
Cameron
7
, Diane Stockton
7
, Jim McMenamin
7
, Mary Ramsay
1,2
1.
Public Health England, London, United Kingdom
2.
NIHR Health Protection Research Unit in Vaccines and Immunisation, London School of
Hygiene and Tropical Medicine, London, United Kingdom
3.
NIHR Health Protection Research Unit in Respiratory Infections, Imperial College London,
United Kingdom
4.
University of Strathclyde, Glasgow, United Kingdom.
5.
Public Health Wales, Cardiff, United Kingdom.
6.
Public Health Agency Northern Ireland, Belfast, United Kingdom.
7.
Public Health Scotland, Glasgow, United Kingdom.
Corresponding author: jamie.lopezbernal2@phe.gov.uk
. CC-BY-NC-ND 4.0 International licenseIt is made available under a
is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)
The copyright holder for this preprint this version posted March 2, 2021. ; https://doi.org/10.1101/2021.03.01.21252652doi: medRxiv preprint
NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.

Abstract
Objectives
To estimate the real-world effectiveness of the Pfizer/BioNTech BNT162b2 vaccine and Astrazeneca
ChAdOx1 vaccine against Confirmed COVID-19, hospitalisations and deaths. To estimate
effectiveness on the UK variant of concern.
Design
Test negative case control design
Setting
Community COVID-19 PCR testing in England
Participants
All adults in England aged 70 years and older (over 7.5 million). All COVID-19 testing in the
community among eligible individuals who reported symptoms between 8
th
December 2020 and 19
th
February 2021 was included in the analysis.
Interventions
One and two doses of BNT162b2 vaccine . One dose of ChAd Ox1 vacci ne.
Main outcome measures
Symptomatic PCR confirmed SARS-CoV-2 infection, hospitalisations and deaths with COVID-19.
Results
Individuals aged >=80 years vaccinated with BNT162b2 prior to 4
th
January, had a higher odds of
testing positive in the first 9 days after vaccination (odds ratio up to 1.48, 95%CI 1.23-1.77),
indicating that those initially targeted had a higher underlying risk of infection. Vaccine effectiveness
was therefore estimated relative to the baseline post-vaccination period. Vaccine effects were noted
from 10-13 days after vaccination, reaching an effectiveness of 70% (95% CI 59-78%) from 28-34
days, then plateauing. From 14 days after the second dose a vaccine effectiveness of 89% (95%CI:
85-93%) was seen.
Individuals aged >=70 years vaccinated from 4
th
January had a similar underlying risk of COVID-19 to
unvaccinated individuals. With BNT162b2, vaccine effectiveness reached 61% (95%CI 51-69%) from
28-34 days after vaccination then plateaued. With the ChAdOx1 vaccine, vaccine effects were seen
from 14-20 days after vaccination reaching an effectiveness of 60% (95%CI 41-73%) from 28-34 days
and further increasing to 73% (95%CI 27-90%) from day 35 onwards.
On top of the protection against symptomatic disease, cases who had been vaccinated with one
dose of BNT162b2 had an additional 43% (95%CI 33-52%) lower risk of emergency hospitalisation
and an additional 51% (95%CI 37-62%) lower risk of death. Cases who had been vaccinated with one
dose of ChAdOx1 had an additional 37% (95% CI 3-59%) lower risk of emergency hospitalisation.
There was insufficient follow-up to assess the effect of ChAdOx1 on mortality due to the later rollout
of this vaccine. Combined with the effect against symptomatic disease, this indicates that a single
dose of either vaccine is approximately 80% effective at preventing hospitalisation and a single dose
of BNT162b2 is 85% effective at preventing death with COVID-19.
Conclusion
Vaccina ti on with ei ther a single do se of BNT162b2 or ChAdOx1 COVID -19 vacc inat ion was associa ted
with a significant reduction in symptomatic SARS-CoV2 positive cases in older adults with even
greater protection against severe disease. Both vaccines show similar effects. Protection was
. CC-BY-NC-ND 4.0 International licenseIt is made available under a
is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)
The copyright holder for this preprint this version posted March 2, 2021. ; https://doi.org/10.1101/2021.03.01.21252652doi: medRxiv preprint

maintaine d for the duration of follow -up (>6 week s) . A second d ose o f BNT162b2 provide s further
protection against symptomatic disease but second doses of ChAdOx1 have not yet been rolled out
in England. There is a clear effect of the vaccines against the UK variant of concern.
. CC-BY-NC-ND 4.0 International licenseIt is made available under a
is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)
The copyright holder for this preprint this version posted March 2, 2021. ; https://doi.org/10.1101/2021.03.01.21252652doi: medRxiv preprint

Introduction
On the 8
th
December 2020 the UK became the first country to implement a COVID-19 vaccination
programme following the approval of the Pfizer-BioNtech messenger RNA (mRNA) vaccine,
BNT162b2, for emergency use.(1) The programme has since expanded to include the AstraZeneca
adenovirus-vector vaccine, ChAdOx1 nCOV-19, and over 6.5 million individuals have now been
vacci nated. The burden of CO VID-19 in the UK remain s high and early evidence on the effec tiven e ss
of vaccines is essential for informing policy decisions on the ongoing rollout of the programme and
the use of other non-pharmaceutical interventions.(2)
During these first few weeks of the programme, the priority groups for vaccination included: (i)
residents in a care home for older adults and their carers; and (ii) all those 80 years of age and over
and frontline health and social care workers.(3) From the 18
th
of January, rollout was expanded to all
adults aged 70 years or older and those in clinically extremely vulnerable groups. Delivery was
initially through hospital trusts and care homes, where possible, subsequently also through primary
care providers and mass vaccination centres. Interim results from phase 3 clinical trials have found
the BNT162b2 and ChAdOx1 vaccines to be highly effective using a two-dose schedule with a target
interval of 3 weeks and 4 weeks respectively between doses.(4, 5) Data from the ChAdOx1 trial
suggests that protection may be greater with a longer dosing interval.(5) A reanalysis of the
BNT162b2 trial data suggests that a single dose of this vaccine has an efficacy of 92.6% in the early
post-vaccination period.(6) Furthermore, with other vaccines an extended interval between the
prime and booster doses typically provides a better immune response to the booster dose.(7, 8)
Based on this evidence, the increasing incidence of COVID-19 in the UK and the need to rapidly
vaccinate as many vulnerable people as possible, on the 20
th
December 2020, the Joint Committee
on Vaccination and Immunisation (JCVI) advised that the dose interval for both vaccines could be
extended to up to 12 weeks. A policy decision was subsequently made to prioritise vaccinating as
many people as possible with the first dose.
Also in December 2020, a new COVID-19 variant of concern (labelled VOC 202012/01) was found to
be associated with increasing case numbers in Kent in South East England.(9) Recent analyses
suggest that this variant has increased transmissibility and it has since become the dominant strain
in large parts of the UK.(10, 11) The variant is characterised by 23 mutations, including mutations to
genes encoding the spike protein, the target in the two vaccines currently in use, as well as the
majority of vaccine candidates.(9) Concerns have been raised on the possible impact of the new
variant on vaccine effectiveness.(12)
Public Health England have undertaken their first analysis of the early effect of COVID-19 vaccination
using routine testing and vaccination data. The aims of this analysis were: (i) to estimate the effect
of vaccination on confirmed COVID-19 in adults aged >=70 years with one and two doses; (ii) to
estimate vaccine effectiveness against the new variant of concern, VOC 202012/01; (iii) to estimate
case hospitalisation and case fatality rates among vaccinated and unvaccinated cases.
. CC-BY-NC-ND 4.0 International licenseIt is made available under a
is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)
The copyright holder for this preprint this version posted March 2, 2021. ; https://doi.org/10.1101/2021.03.01.21252652doi: medRxiv preprint

Methods
This study estimates the effect of vaccination with the BNT162b2 and ChAdOx1 COVID-19 vaccines
on laboratory confirmed symptomatic disease in individuals aged 70 years or older in England.
All individuals aged 70 years or older in England (over 7.5 million individuals) were eligible for
inclusion.
A test negative case control design was used to estimate odds ratios for testing positive for SARS-
CoV-2 in all vaccinated compared to unvaccinated individuals with compatible symptoms who were
tested using PCR. Test negative case control designs are considered powerful study designs for
estimating vaccine effectiveness and are used extensively for estimating effectiveness of influenza
vaccines and vaccines against other respiratory viruses.(13-15) They have been found to have high
concordance with randomised controlled trials.(16, 17) Vaccination status is compared in individuals
testing positive for the target organism compared to those testing negative. Comparing to other
individuals presenting for testing but testing negative helps to control for factors that are typically
difficult to estimate in observational studies including differences in health seeking behaviour,
access to testing and case ascertainment.
Data sources
Outcome assessment
Testing for COVID-19 in the UK is conducted through hospital and public health laboratories for
those with a clinical need as well as some healthcare workers (referred to as Pillar 1) and through
community testing (referred to as Pillar 2).(18) Anybody can access a Pillar 2 test if they have
coronavirus symptoms (high temperature, new continuous cough, loss or change in sense of smell or
taste), or if they are part of a local or national mass testing programme. For this analysis, PCR testing
data from Pillar 2 in individuals who reported having symptoms were included, data were extracted
for all te sts between 26
th
of October 2020 and the 21
st
of February 2021.
The mutations to the Spike (S) gene in VOC 202012/01 cause a reproducible S gene target failure
(SGTF) in laboratories using a three target from Thermo Fisher (TaqPath) PCR assay.(9) Between
week commencing 7
th
of December 2020 and week commencing 25
th
of January 2021, VOC
202012/01 accounted for be twe en 98 and 100% of SGTF in England.(19) SGTF therefo re provide s a
good proxy for identification of VOC 202012/01 without relying on sequencing. An analysis of the
vacci ne effects again s t COVID -19 de tecti ons with SGTF was under taken restric ted to data from
laboratories using the TaqPath assay.
Exposure assessment
Testing data were linked to individual vaccination histories from the national vaccination register
(the National Immunisation Management System, NIMS) using NHS number, date of birth, surname,
forename and postcode. All COVID-19 vaccines administered in England are recorded in the NIMS by
clinici ans through point of care applications. The NIMS data were ext ract ed on February 22
nd
2021
with immunisations to February 21
st
2021. To allow for delayed entry of data into NIMS only samples
taken from February 19
th
2021 were included in analyses.
Secondary outcomes
The data were also linked to hospitalisation data from the Emergency Care Dataset (ECDS), which
includes hospital admissions via emergency departments but not elective admissions, and to deaths
data from NHS records.(20)
. CC-BY-NC-ND 4.0 International licenseIt is made available under a
is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review)
The copyright holder for this preprint this version posted March 2, 2021. ; https://doi.org/10.1101/2021.03.01.21252652doi: medRxiv preprint

Citations
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Journal ArticleDOI
TL;DR: In this article, the authors examined the proportion and probability of self-reported systemic and local side-effects within 8 days of vaccination in individuals using the COVID Symptom Study app who received one or two doses of the BNT162b2 vaccine or one dose of the ChAdOx1 nCoV-19 vaccine.
Abstract: Summary Background The Pfizer-BioNTech (BNT162b2) and the Oxford-AstraZeneca (ChAdOx1 nCoV-19) COVID-19 vaccines have shown excellent safety and efficacy in phase 3 trials. We aimed to investigate the safety and effectiveness of these vaccines in a UK community setting. Methods In this prospective observational study, we examined the proportion and probability of self-reported systemic and local side-effects within 8 days of vaccination in individuals using the COVID Symptom Study app who received one or two doses of the BNT162b2 vaccine or one dose of the ChAdOx1 nCoV-19 vaccine. We also compared infection rates in a subset of vaccinated individuals subsequently tested for SARS-CoV-2 with PCR or lateral flow tests with infection rates in unvaccinated controls. All analyses were adjusted by age (≤55 years vs >55 years), sex, health-care worker status (binary variable), obesity (BMI Findings Between Dec 8, and March 10, 2021, 627 383 individuals reported being vaccinated with 655 590 doses: 282 103 received one dose of BNT162b2, of whom 28 207 received a second dose, and 345 280 received one dose of ChAdOx1 nCoV-19. Systemic side-effects were reported by 13·5% (38 155 of 282 103) of individuals after the first dose of BNT162b2, by 22·0% (6216 of 28 207) after the second dose of BNT162b2, and by 33·7% (116 473 of 345 280) after the first dose of ChAdOx1 nCoV-19. Local side-effects were reported by 71·9% (150 023 of 208 767) of individuals after the first dose of BNT162b2, by 68·5% (9025 of 13 179) after the second dose of BNT162b2, and by 58·7% (104 282 of 177 655) after the first dose of ChAdOx1 nCoV-19. Systemic side-effects were more common (1·6 times after the first dose of ChAdOx1 nCoV-19 and 2·9 times after the first dose of BNT162b2) among individuals with previous SARS-CoV-2 infection than among those without known past infection. Local effects were similarly higher in individuals previously infected than in those without known past infection (1·4 times after the first dose of ChAdOx1 nCoV-19 and 1·2 times after the first dose of BNT162b2). 3106 of 103 622 vaccinated individuals and 50 340 of 464 356 unvaccinated controls tested positive for SARS-CoV-2 infection. Significant reductions in infection risk were seen starting at 12 days after the first dose, reaching 60% (95% CI 49–68) for ChAdOx1 nCoV-19 and 69% (66–72) for BNT162b2 at 21–44 days and 72% (63–79) for BNT162b2 after 45–59 days. Interpretation Systemic and local side-effects after BNT162b2 and ChAdOx1 nCoV-19 vaccination occur at frequencies lower than reported in phase 3 trials. Both vaccines decrease the risk of SARS-CoV-2 infection after 12 days. Funding ZOE Global, National Institute for Health Research, Chronic Disease Research Foundation, National Institutes of Health, UK Medical Research Council, Wellcome Trust, UK Research and Innovation, American Gastroenterological Association.

670 citations

Journal ArticleDOI
TL;DR: A post-hoc analysis of the efficacy of the adenoviral vector vaccine, ChAdOx1 nCoV-19 (AZD1222), against B.1.7, emerged as the dominant cause of COVID-19 disease in the UK from November, 2020 as discussed by the authors.

521 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigated the association between the mass roll-out of the first doses of these COVID-19 vaccines and hospital admissions for CoV-19 and found that the first dose of the BNT162b2 mRNA vaccine was associated with a vaccine effect of 91% (95% CI 85-94) for reduced COVID19 hospital admission at 28-34 days post-vaccination.

437 citations

Journal ArticleDOI
TL;DR: Most COVID-19 vaccines have been designed to elicit immune responses, ideally neutralizing antibodies (NAbs), against the SARS-CoV-2 spike protein this article.
Abstract: Most COVID-19 vaccines are designed to elicit immune responses, ideally neutralizing antibodies (NAbs), against the SARS-CoV-2 spike protein. Several vaccines, including mRNA, adenoviral-vectored, protein subunit and whole-cell inactivated virus vaccines, have now reported efficacy in phase III trials and have received emergency approval in many countries. The two mRNA vaccines approved to date show efficacy even after only one dose, when non-NAbs and moderate T helper 1 cell responses are detectable, but almost no NAbs. After a single dose, the adenovirus vaccines elicit polyfunctional antibodies that are capable of mediating virus neutralization and of driving other antibody-dependent effector functions, as well as potent T cell responses. These data suggest that protection may require low levels of NAbs and might involve other immune effector mechanisms including non-NAbs, T cells and innate immune mechanisms. Identifying the mechanisms of protection as well as correlates of protection is crucially important to inform further vaccine development and guide the use of licensed COVID-19 vaccines worldwide.

367 citations

Journal ArticleDOI
18 Nov 2021-BMJ
TL;DR: A systematic review and meta-analysis suggests that several personal protective and social measures, including handwashing, mask wearing, and physical distancing are associated with reductions in the incidence covid-19 as mentioned in this paper.
Abstract: Objective To review the evidence on the effectiveness of public health measures in reducing the incidence of covid-19, SARS-CoV-2 transmission, and covid-19 mortality. Design Systematic review and meta-analysis. Data sources Medline, Embase, CINAHL, Biosis, Joanna Briggs, Global Health, and World Health Organization COVID-19 database (preprints). Eligibility criteria for study selection Observational and interventional studies that assessed the effectiveness of public health measures in reducing the incidence of covid-19, SARS-CoV-2 transmission, and covid-19 mortality. Main outcome measures The main outcome measure was incidence of covid-19. Secondary outcomes included SARS-CoV-2 transmission and covid-19 mortality. Data synthesis DerSimonian Laird random effects meta-analysis was performed to investigate the effect of mask wearing, handwashing, and physical distancing measures on incidence of covid-19. Pooled effect estimates with corresponding 95% confidence intervals were computed, and heterogeneity among studies was assessed using Cochran’s Q test and the I2 metrics, with two tailed P values. Results 72 studies met the inclusion criteria, of which 35 evaluated individual public health measures and 37 assessed multiple public health measures as a “package of interventions.” Eight of 35 studies were included in the meta-analysis, which indicated a reduction in incidence of covid-19 associated with handwashing (relative risk 0.47, 95% confidence interval 0.19 to 1.12, I2=12%), mask wearing (0.47, 0.29 to 0.75, I2=84%), and physical distancing (0.75, 0.59 to 0.95, I2=87%). Owing to heterogeneity of the studies, meta-analysis was not possible for the outcomes of quarantine and isolation, universal lockdowns, and closures of borders, schools, and workplaces. The effects of these interventions were synthesised descriptively. Conclusions This systematic review and meta-analysis suggests that several personal protective and social measures, including handwashing, mask wearing, and physical distancing are associated with reductions in the incidence covid-19. Public health efforts to implement public health measures should consider community health and sociocultural needs, and future research is needed to better understand the effectiveness of public health measures in the context of covid-19 vaccination. Systematic review registration PROSPERO CRD42020178692.

270 citations

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Frequently Asked Questions (10)
Q1. What contributions have the authors mentioned in the paper "Early effectiveness of covid-19 vaccination with bnt162b2 mrna vaccine and chadox1 adenovirus vector vaccine on symptomatic disease, hospitalisations and mortality in older adults in england" ?

All COVID-19 testing in the community among eligible individuals who reported symptoms between 8 th December 2020 and 19 th February 2021 was included in the analysis. It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. With the ChAdOx1 vaccine, vaccine effects were seen from 14-20 days after vaccination reaching an effectiveness of 60 % ( 95 % CI 41-73 % ) from 28-34 days and further increasing to 73 % ( 95 % CI 27-90 % ) from day 35 onwards. 

Further evidence is needed on the duration of any effect and the effect against asymptomatic infection and transmission and the four UK nations will work closely to develop and share evidence on this as it becomes available. What this study adds: • A single dose of either vaccine provides significant protection against COVID-19 and further protection against severe disease lasting at least 6 weeks, including against the UK variant of concern. 

With the ChAdOx1 vaccine, vaccine effects were seen from 14-20 days after vaccination reaching an effectiveness of 60% (95%CI 41-73%) from 28-34 days and further increasing to 73% (95%CI 27-90%) from day 35 onwards. 

On top of the protection against symptomatic disease, cases who had been vaccinated with one dose of BNT162b2 had an additional 43% (95%CI 33-52%) lower risk of emergency hospitalisation and an additional 51% (95%CI 37-62%) lower risk of death. 

Vaccination with either a single dose of BNT162b2 or ChAdOx1 COVID-19 vaccination was associated with a significant reduction in symptomatic SARS-CoV2 positive cases in older adults with even greater protection against severe disease. 

Combined with the effect against symptomatic disease, this indicates that a single dose of either vaccine is approximately 80% effective at preventing hospitalisation and a single dose of BNT162b2 is 85% effective at preventing death with COVID-19. 

Vaccine effects were noted from 10-13 days after vaccination, reaching an effectiveness of 70% (95% CI 59-78%) from 28-34 days, then plateauing. 

Test negative case control designCommunity COVID-19 PCR testing in EnglandAll adults in England aged 70 years and older (over 7.5 million). 

A second dose of BNT162b2 provides further protection against symptomatic disease but second doses of ChAdOx1 have not yet been rolled out in England. 

Individuals aged >=80 years vaccinated with BNT162b2 prior to 4th January, had a higher odds of testing positive in the first 9 days after vaccination (odds ratio up to 1.48, 95%CI 1.23-1.77), indicating that those initially targeted had a higher underlying risk of infection. 

Trending Questions (1)
Is it bad to get the first Covid vaccine twice?

Combined with the effect against symptomatic disease, this indicates that a single dose of either vaccine is approximately 80% effective at preventing hospitalisation and a single dose of BNT162b2 is 85% effective at preventing death with COVID-19.