scholarly journals Effectiveness of BNT162b2 (Comirnaty, Pfizer-BioNTech) COVID-19 booster vaccine against covid-19 related symptoms in England: test negative case-control study

2021 ◽  
Author(s):  
Nick Andrews ◽  
Julia Stowe ◽  
Freja Kirsebom ◽  
Charlotte Gower ◽  
Mary Ramsay ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Booster Dose ◽  
Secondary Analysis ◽  
Vaccine Dose ◽  
Case Control ◽  
Symptomatic Disease ◽  
Booster Vaccine ◽  
Real World Evidence ◽  
Negative Case ◽  
The Uk

Background In September 2021, the UK Government introduced a booster programme targeting individuals over 50 and those in a clinical risk group. Individuals were offered either a full dose of the BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine or a half dose of the mRNA-1273 (Spikevax, Moderna) vaccine, irrespective of the vaccine received as the primary course Methods We used a test-negative case-control design to estimate the Vaccine Effectiveness (VE) of the booster dose BNT162b2 (Comirnaty, Pfizer-BioNTech) in those aged over 50 against symptomatic disease in post booster time intervals compared to individuals at least 140 days post a second dose with no booster dose recorded. In a secondary analysis, we also compared to unvaccinated individuals and to the 2 to 6 day period after a booster dose was received. Analyses were stratified by which primary doses had been received and any mixed primary courses were excluded. Results The relative VE estimate in the 14 days after the BNT162b2 (Comirnaty, Pfizer-BioNTech) booster dose, compared to individuals that received a two-dose primary course, was 87.4 (95% confidence interval 84.9-89.4) in those individuals who received two doses ChAdOx1-S (Vaxzevria, AstraZeneca) as a primary course and 84.4 (95% confidence interval 82.8-85.8) in those individuals who received two doses of BNT162b2 (Comirnaty, Pfizer-BioNTech) as a primary course. Using the 2-6 day period post the booster dose as the baseline gave similar results. The absolute VE from 14 days after the booster, using the unvaccinated baseline, was 93.1(95% confidence interval 91.7-94.3) in those with ChAdOx1-S (Vaxzevria, AstraZeneca) as their primary course and 94.0 (93.4-94.6) for BNT162b2 (Comirnaty, Pfizer-BioNTech) as their primary course. Conclusions Our study provides real world evidence of significant increased protection from the booster vaccine dose against symptomatic disease in those aged over 50 year of age irrespective of which primary course was received.

scholarly journals Adolescent vaccination with BNT162b2 (Comirnaty, Pfizer-BioNTech) vaccine and effectiveness of the first dose against COVID-19: national test-negative case-control study, England

2021 ◽  
Author(s):  
Annabel A Powell ◽  
Freja Kirsebom ◽  
Julia Stowe ◽  
Kelsey McOwat ◽  
Vanessa Saliba ◽  
...  
Keyword(s):  
Vaccine Dose ◽  
Immunisation Programme ◽  
Case Control ◽  
Symptomatic Disease ◽  
Negative Case ◽  
Community Transmission ◽  
Adolescent Vaccination ◽  
The Uk ◽  
National Test ◽  
Control Study

AbstractAdolescents in the UK were recommended to have their first dose of mRNA vaccine during a period of high community transmission due to the highly transmissible Delta variant, followed by a second dose at an extended interval of 8-12 weeks. We used national SARS-CoV-2 testing, vaccination and hospitalisation data to estimate vaccine effectiveness (VE) using a test-negative case-control design, against PCR-confirmed symptomatic COVID-19 in England. VE against symptomatic disease increased to 80% within two weeks of the first dose of BNT162b2 vaccine (higher than in adults aged 18-64 years) and then declines rapidly to 40% within 8 weeks (similar to adults). Early data in 16-17-year-olds also indicate high protection against hospitalisation and a rapid increase in VE against symptomatic COVID-19 after the second dose. Our data highlight the importance of the second vaccine dose for protection against symptomatic COVID-19 and raise important questions about the objectives of an adolescent immunisation programme. If prevention of infection is the primary aim, then regular COVID-19 vaccine boosters will be required.

scholarly journals Self-reported and physiological reactions to the third BNT162b2 mRNA COVID-19 (booster) vaccine dose

2021 ◽  
Author(s):  
Merav Mofaz ◽  
Matan Yechezkel ◽  
Grace Guan ◽  
Margaret L. Brandeau ◽  
Tal Patalon ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Booster Dose ◽  
Vaccination Campaign ◽  
Vaccine Dose ◽  
P Value ◽  
Booster Vaccine ◽  
The Third ◽  
Systemic Reactions ◽  
Physiological Reactions

AbstractBackgroundThe rapid rise in hospitalizations associated with the Delta-driven COVID-19 resurgence, and the imminent risk of hospital overcrowding, led the Israeli government to initialize a national third (booster) COVID-19 vaccination campaign in early August 2021, offering the BNT162b2 mRNA vaccine to individuals who received their second dose over five months ago. However, the safety of the third (booster) dose has not been fully established yet.ObjectiveEvaluate the short-term, self-reported and physiological reactions to the third BNT162b2 mRNA COVID-19 (booster) vaccine dose.DesignA prospective observational study, in which participants are equipped with a smartwatch and fill in a daily questionnaire via a dedicated mobile application for a period of 21 days, starting seven days before the vaccination.SettingAn Israel-wide third (booster) vaccination campaign.ParticipantsA group of 1,609 (18+ years of age) recipients of at least one dose of the BNT162b2 vaccine between December 20, 2020, and September 15, 2021, out of a larger cohort of 2,912 prospective study participants. 1,344 of the participants were recipients of the third vaccine dose.MeasurementsDaily self-reported questionnaires regarding local and systemic reactions, mood level, stress level, sport duration, and sleep quality. Heart rate, heart rate variability and blood oxygen saturation level were continuously measured by Garmin Vivosmart 4 smartwatches.ResultsThe extent of systemic reactions reported following the third (booster) dose administration is similar to that reported following the second dose (p-value=0.305) and considerably greater than that reported following the first dose (p-value<0.001). Our analyses of self-reported well-being indicators as well as the objective heart rate and heart rate variability measures recorded by the smartwatches further support this finding. Focusing on the third dose, reactions were more apparent in younger participants (p-value<0.01), in women (p-value<0.001), and in participants with no underlying medical conditions (p-value<0.001). Nevertheless, reported reactions and changes in physiological measures returned to their baseline levels within three days from inoculation with the third dose.LimitationsParticipants may not adequately represent the vaccinated population in Israel and elsewhere.ConclusionOur work further supports the safety of a third COVID-19 BNT162b2 mRNA (booster) vaccine dose from both a subjective and an objective perspective, particularly in individuals 65+ years of age and those with underlying medical conditions.Primary funding sourceEuropean Research Council (ERC) project #949850

A Multicenter Case-Control Prospective Study to Assess the Risk of Immune Thrombocytopenia (ITP) Associated with Vaccines in Adults Using the PGRx-ITP Registry

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1169-1169 ◽  
Author(s):  
Lamiae Grimaldi-Bensouda ◽  
Marc Michel ◽  
Jean-François Viallard ◽  
Daniel Adoue ◽  
Nadine Magy-Bertrand ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Odds Ratio ◽  
Immune Thrombocytopenia ◽  
Index Date ◽  
Adjusted Odds Ratio ◽  
Time Window ◽  
Case Reports ◽  
Secondary Analysis ◽  
Case Control ◽  
Research Fellowship

Abstract Abstract 1169 Background and objectives Immune thrombocytopenia (ITP) is thought to result from an autoimmune mechanism, and some case-reports have suggested that immunizations could be involved and trigger the autoimmune process. This prospective multicenter case-control study investigated for the first time associations between ITP and vaccination in adults, particularly between ITP and influenza vaccinations. Methods Over a three year period, a network of 15 physicians from hematology and internal medicine referral centers across France recruited newly diagnosed cases of primary ITP in patients aged over 15 years fulfilling the ITP standardized criteria of the American Society of Hematology. Recruiting physicians completed standardized forms for each patient and every patient underwent a standardized 1 hour-interview focused on previous medications and vaccinations in the last 12 months. Incident ITP cases were compared to sex and age-matched controls selected and recruited from general practice settings, also from the same geographically areas of France. The method of referent recruitment has been described elsewhere (Grimaldi-Bensouda et al. 2010 Pharmacoepidemiol Drug Saf 2010;19(6):591–5). Controls were also interviewed in the same standardized way as cases. Cases and control were compared in respect of various descriptive factors and potential risk factors for ITP. Written or other confirmation of vaccinations was sought from both the patient and his/her physician. The time window defining exposure to vaccines was 12 months before the index date. In secondary analysis, the most prevalent vaccines in adults were analyzed. Results Two hundred and twenty four cases fulfilling the inclusion criteria and 4412 were included in the study. Seventy eight of the 224 cases (34.8%) and 1566 of 4412 controls (35.5%) received a vaccination within this time window [adjusted odds ratio 0.97, 95% confidence interval 0.70–1.33]. Twenty percent of the cases and 26% of controls received an influenza vaccine [adjusted odds ratio 0.66, 95% confidence interval 0.45–0.98]. Other prevalent vaccines in adult are currently under study. Conclusions This systematic case-control design is well-suited to study rare disorders such as ITP and few such studies have been conducted. Another advantage was the minimization of recall bias because questions about vaccinations were included in a standardized interview focusing on exposure to all medications. When all vaccines were considered, we found no association between vaccination and the incidence of ITP in either crude or adjusted analyses. Moreover, cases were less likely than controls to have been vaccinated against influenza in the 12 months before the index date. Disclosures: Grimaldi-Bensouda: LA-SER: Employment; INSERM: I was the recipient of a research fellowship from the INSERM (French National Institute for Health and Medical Research) at the time of the study. Leighton:LA-SER Europe Ltd: Employment. Aubrun:LA-SER Europe Ltd: Employment. Abenhaim:LA-SER Europe Ltd: I'm a stock owner and chairman of LA-SER, the company conducting the study.

scholarly journals Vaccine effectiveness and duration of protection of Comirnaty, Vaxzevria and Spikevax against mild and severe COVID-19 in the UK

2021 ◽  
Author(s):  
Nick Andrews ◽  
Elise Tessier ◽  
Julia Stowe ◽  
Charlotte Gower ◽  
Freja Kirsebom ◽  
...  
Keyword(s):  
Severe Disease ◽  
Vaccine Effectiveness ◽  
Real World Data ◽  
Post Vaccination ◽  
Symptomatic Disease ◽  
Negative Case ◽  
The Uk ◽  
Comorbidity Status ◽  
Duration Of Protection ◽  
Over Time

Background COVID-19 vaccines have been used for 9 months in the UK. Real world data have demonstrated the vaccines to be highly effective against COVID-19, severe disease and death. Here, we estimate vaccine effectiveness over time since the second dose of Comirnaty, Vaxzevria and Spikevax in England. Methods We used a test-negative case-control design to estimate vaccine effectiveness against symptomatic disease, hospitalisation and mortality by age, comorbidity status and over time after the second dose to investigate waning separately for Alpha and Delta variants. Results Vaccine effectiveness against symptomatic disease peaked in the early weeks after the second dose and then fell to 47.3 (95% CI 45 to 49.6) and 69.7 (95% CI 68.7 to 70.5) by 20+ weeks against the Delta variant for Vaxzevria and Comirnaty, respectively. Waning of vaccine effectiveness was greater for 65+ year-olds compared to 40-64 year-olds. Vaccine effectiveness fell less against hospitalisations to 77.0 (70.3 to 82.3) and 92.7 (90.3 to 94.6) beyond 20 weeks post-vaccination and 78.7 (95% CI 52.7 to 90.4) and 90.4 (95% CI 85.1 to 93.8) against death for Vaxzevria and Comirnaty, respectively. Greater waning was observed among 65+ year-olds in a clinically extremely vulnerable group and 40-64-year olds with underlying medical conditions compared to healthy adults. Conclusions We observed limited waning in vaccine effectiveness against hospitalisation and death more than 20 weeks post-vaccination with Vaxzevria or Comirnaty. Waning was greater in older adults and those in a clinical risk group, suggesting that these individuals should be prioritised for booster doses.

scholarly journals Effectiveness of COVID-19 vaccines against the B.1.617.2 variant

2021 ◽  
Author(s):  
Jamie Lopez Bernal ◽  
Nick Andrews ◽  
Charlotte Gower ◽  
Eileen Gallagher ◽  
Ruth Simmons ◽  
...  
Keyword(s):  
Vaccine Effectiveness ◽  
Vaccine Uptake ◽  
Vulnerable Groups ◽  
Gene Target ◽  
Symptomatic Disease ◽  
Negative Case ◽  
Notable Increase ◽  
The Uk ◽  
Status Data ◽  
Predominant Strain

Background: The B.1.617.2 COVID-19 variant has contributed to the surge in cases in India and has now been detected across the globe, including a notable increase in cases in the UK. We estimate the effectiveness of the BNT162b2 and ChAdOx1 COVID-19 vaccines against this variant. Methods: A test negative case control design was used to estimate the effectiveness of vaccination against symptomatic disease with both variants over the period that B.1.617.2 began circulating with cases identified based on sequencing and S-gene target status. Data on all symptomatic sequenced cases of COVID-19 in England was used to estimate the proportion of cases with B.1.617.2 compared to the predominant strain (B.1.1.7) by vaccination status. Results: Effectiveness was notably lower after 1 dose of vaccine with B.1.617.2 cases 33.5% (95%CI: 20.6 to 44.3) compared to B.1.1.7 cases 51.1% (95%CI: 47.3 to 54.7) with similar results for both vaccines. With BNT162b2 2 dose effectiveness reduced from 93.4% (95%CI: 90.4 to 95.5) with B.1.1.7 to 87.9% (95%CI: 78.2 to 93.2) with B.1.617.2. With ChAdOx1 2 dose effectiveness reduced from 66.1% (95% CI: 54.0 to 75.0) with B.1.1.7 to 59.8% (95%CI: 28.9 to 77.3) with B.1.617.2. Sequenced cases detected after 1 or 2 doses of vaccination had a higher odds of infection with B.1.617.2 compared to unvaccinated cases (OR 1.40; 95%CI: 1.13-1.75). Conclusions: After 2 doses of either vaccine there were only modest differences in vaccine effectiveness with the B.1.617.2 variant. Absolute differences in vaccine effectiveness were more marked with dose 1. This would support maximising vaccine uptake with two doses among vulnerable groups.

scholarly journals Effectiveness of COVID-19 vaccines against the Omicron (B.1.1.529) variant of concern

2021 ◽  
Author(s):  
Nick Andrews ◽  
Julia Stowe ◽  
Freja Kirsebom ◽  
Samuel Toffa ◽  
Tim Rickeard ◽  
...  
Keyword(s):  
Control Design ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Post Dose ◽  
Symptomatic Disease ◽  
Primary Immunisation ◽  
Negative Case ◽  
Negative Controls

Abstract Background A rapid increase in cases due to the SARS-CoV-2 Omicron (B.1.1.529) variant in highly vaccinated populations has raised concerns about the effectiveness of current vaccines. Methods We used a test-negative case-control design to estimate vaccine effectiveness (VE) against symptomatic disease caused by the Omicron and Delta variants in England. VE was calculated after primary immunisation with two BNT162b2 or ChAdOx1 doses, and at 2+ weeks following a BNT162b2 booster. Results Between 27 November and 06 December 2021, 581 and 56,439 eligible Omicron and Delta cases respectively were identified. There were 130,867 eligible test-negative controls. There was no effect against Omicron from 15 weeks after two ChAdOx1 doses, while VE after two BNT162b2 doses was 88.0% (95%CI: 65.9 to 95.8%) 2-9 weeks after dose 2, dropping to between 34 and 37% from 15 weeks post dose 2.From two weeks after a BNT162b2 booster, VE increased to 71.4% (95%CI: 41.8 to 86.0%) for ChAdOx1 primary course recipients and 75.5% (95%CI: 56.1 to 86.3%) for BNT162b2 primary course recipients. For cases with Delta, VE was 41.8% (95%CI: 39.4-44.1%) at 25+ weeks after two ChAdOx1 doses, increasing to 93.8% (95%CI: 93.2-94.3%) after a BNT162b2 booster. With a BNT162b2 primary course, VE was 63.5% (95%CI: 61.4 to 65.5%) 25+ weeks after dose 2, increasing to 92.6% (95%CI: 92.0-93.1%) two weeks after the booster. Conclusions Primary immunisation with two BNT162b2 or ChAdOx1 doses provided no or limited protection against symptomatic disease with the Omicron variant. Boosting with BNT162b2 following either primary course significantly increased protection.

scholarly journals Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital admissions, and mortality in older adults in England: test negative case-control study

BMJ ◽  
2021 ◽  
pp. n1088
Author(s):  
Jamie Lopez Bernal ◽  
Nick Andrews ◽  
Charlotte Gower ◽  
Chris Robertson ◽  
Julia Stowe ◽  
...  
Keyword(s):  
Case Control Study ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Symptomatic Disease ◽  
Emergency Hospital Admission ◽  
Negative Case ◽  
Control Study ◽  
Underlying Risk ◽  
Reduced Risk

Abstract Objective To estimate the real world effectiveness of the Pfizer-BioNTech BNT162b2 and Oxford-AstraZeneca ChAdOx1-S vaccines against confirmed covid-19 symptoms (including the UK variant of concern B.1.1.7), admissions to hospital, and deaths. Design Test negative case-control study. Setting Community testing for covid-19 in England. Participants 156 930 adults aged 70 years and older who reported symptoms of covid-19 between 8 December 2020 and 19 February 2021 and were successfully linked to vaccination data in the National Immunisation Management System. Interventions Vaccination with BNT162b2 or ChAdOx1-S. Main outcome measures Primary outcomes were polymerase chain reaction confirmed symptomatic SARS-CoV-2 infections, admissions to hospital for covid-19, and deaths with covid-19. Results Participants aged 80 years and older vaccinated with BNT162b2 before 4 January 2021 had a higher odds of testing positive for covid-19 in the first nine days after vaccination (odds ratio up to 1.48, 95% confidence interval 1.23 to 1.77), indicating that those initially targeted had a higher underlying risk of infection. Vaccine effectiveness was therefore compared with the baseline post-vaccination period. Vaccine effects were noted 10 to 13 days after vaccination, reaching a vaccine effectiveness of 70% (95% confidence interval 59% to 78%), then plateauing. From 14 days after the second dose a vaccination effectiveness of 89% (85% to 93%) was found compared with the increased baseline risk. Participants aged 70 years and older vaccinated from 4 January (when ChAdOx1-S delivery commenced) had a similar underlying risk of covid-19 to unvaccinated individuals. With BNT162b2, vaccine effectiveness reached 61% (51% to 69%) from 28 to 34 days after vaccination, then plateaued. With ChAdOx1-S, effects were seen from 14 to 20 days after vaccination, reaching an effectiveness of 60% (41% to 73%) from 28 to 34 days, increasing to 73% (27% to 90%) from day 35 onwards. On top of the protection against symptomatic disease, a further 43% (33% to 52%) reduced risk of emergency hospital admission and 51% (37% to 62%) reduced risk of death was observed in those who had received one dose of BNT162b2. Participants who had received one dose of ChAdOx1-S had a further 37% (3% to 59%) reduced risk of emergency hospital admission. Follow-up was insufficient to assess the effect of ChAdOx1-S on mortality. Combined with the effect against symptomatic disease, a single dose of either vaccine was about 80% effective at preventing admission to hospital with covid-19 and a single dose of BNT162b2 was 85% effective at preventing death with covid-19. Conclusion Vaccination with either one dose of BNT162b2 or ChAdOx1-S was associated with a significant reduction in symptomatic covid-19 in older adults, and with further protection against severe disease. Both vaccines showed similar effects. Protection was maintained for the duration of follow-up (>6 weeks). A second dose of BNT162b2 was associated with further protection against symptomatic disease. A clear effect of the vaccines against the B.1.1.7 variant was found.

scholarly journals Influenza vaccine effectiveness against influenza A in children based on the results of various rapid influenza tests in the 2018/19 season

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0249005
Author(s):  
Masayoshi Shinjoh ◽  
Norio Sugaya ◽  
Yoshio Yamaguchi ◽  
Ichiro Ookawara ◽  
Yuji Nakata ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Influenza Vaccine ◽  
Diagnostic Tests ◽  
Influenza A ◽  
Control Design ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Test Results ◽  
Negative Case ◽  
Influenza A H1n1

During influenza epidemics, Japanese clinicians routinely conduct rapid influenza diagnostic tests (RIDTs) in patients with influenza-like illness, and patients with positive test results are treated with anti-influenza drugs within 48 h after the onset of illness. We assessed the vaccine effectiveness (VE) of inactivated influenza vaccine (IIV) in children (6 months–15 years old, N = 4243), using a test-negative case-control design based on the results of RIDTs in the 2018/19 season. The VE against influenza A(H1N1)pdm and A(H3N2) was analyzed separately using an RIDT kit specifically for detecting A(H1N1)pdm09. The adjusted VE against combined influenza A (H1N1pdm and H3N2) and against A(H1N1)pdm09 was 39% (95% confidence interval [CI], 30%–46%) and 74% (95% CI, 39%–89%), respectively. By contrast, the VE against non-A(H1N1)pdm09 influenza A (presumed to be H3N2) was very low at 7%. The adjusted VE for preventing hospitalization was 56% (95% CI, 16%–77%) against influenza A. The VE against A(H1N1)pdm09 was consistently high in our studies. By contrast, the VE against A(H3N2) was low not only in adults but also in children in the 2018/19 season.

scholarly journals Femininity, Childhood and the Non-Making of a Sporting Celebrity: The Beth Tweddle Case

2013 ◽  
Vol 18 (3) ◽  
pp. 178-187 ◽  
Author(s):  
Rachel Lara Cohen
Keyword(s):  
Media Coverage ◽  
Female Athletes ◽  
Secondary Analysis ◽  
Primary Analysis ◽  
London 2012 ◽  
Negative Case ◽  
The Social ◽  
Social Invisibility ◽  
The Uk ◽  
Olympic Sport

Gymnastics is regularly classified as a feminine-appropriate sport, embodying grace and elegance and is an Olympic sport which has regularly produced female sporting celebrities. Beth Tweddle is the most successful British gymnast of all time and the first to achieve international success, culminating in a medal at London 2012, yet she has received relatively little media coverage and few corporate endorsements. Employing a ‘negative case’ methodology, this athlete's relative lack of celebrity is investigated. The article suggests that it can be explained by (a) contradictions underpinning the gender-designation of gymnastics, and (b) the social invisibility of a core audience for the sport: young girls. An implication is that the achievement of celebrity within ‘feminine’ sport may be increasingly unattainable, especially for female athletes. The article uses mixed methods, including primary analysis of print and social media and secondary analysis of a national survey of young people in the UK.

scholarly journals 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

2021 ◽  
Author(s):  
Jamie Lopez Bernal ◽  
Nick Andrews ◽  
Charlotte Gower ◽  
Julia Stowe ◽  
Chris Robertson ◽  
...  
Keyword(s):  
Older Adults ◽  
Single Dose ◽  
Lower Risk ◽  
Vaccine Effectiveness ◽  
Symptomatic Disease ◽  
Risk Of Death ◽  
Negative Case ◽  
The Uk ◽  
Underlying Risk

AbstractObjectivesTo 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.DesignTest negative case control designSettingCommunity COVID-19 PCR testing in EnglandParticipantsAll 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 8thDecember 2020 and 19thFebruary 2021 was included in the analysis.InterventionsOne and two doses of BNT162b2 vaccine. One dose of ChAdOx1 vaccine.Main outcome measuresSymptomatic PCR confirmed SARS-CoV-2 infection, hospitalisations and deaths with COVID-19.ResultsIndividuals aged >=80 years vaccinated with BNT162b2 prior to 4thJanuary, 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 4thJanuary 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.ConclusionVaccination 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.

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