scholarly journals Vaccine effectiveness against COVID-19 related hospital admission in the Netherlands: a test-negative case-control study

2021 ◽  
Author(s):  
Annabel FA Niessen ◽  
Mirjam J Knol ◽  
Susan JM Hahne ◽  
Marc JM Bonten ◽  
Patricia PCJL Bruijning-Verhagen ◽  
...  
Keyword(s):  
Hospital Admission ◽  
Protective Effect ◽  
Case Control Study ◽  
Patient Characteristics ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Icu Admission ◽  
Negative Case ◽  
Home Residency ◽  
Control Study

Introduction: Real-world vaccine effectiveness (VE) estimates are essential to identify potential groups at higher risk of break-through infections and to guide policy. We assessed the VE of COVID-19 vaccination against COVID-19 hospitalization, while adjusting and stratifying for patient characteristics. Methods: We performed a test-negative case-control study in six Dutch hospitals. The study population consisted of adults eligible for COVID-19 vaccination hospitalized between May 1 and June 28 2021 with respiratory symptoms. Cases were defined as patients who tested positive for SARS-CoV-2 by PCR during the first 48 hours of admission or within 14 days prior to hospital admission. Controls were patients tested negative at admission and did not have a positive test during the 2 weeks prior to hospitalization. VE was calculated using multivariable logistic regression, adjusting for calendar week, sex, age, comorbidity and nursing home residency. Subgroup analysis was performed for age, sex and different comorbidities. Secondary endpoints were ICU-admission and mortality. Results: 379 cases and 255 controls were included of whom 157 (18%) were vaccinated prior to admission. Five cases (1%) and 40 controls (16%) were fully vaccinated (VE: 93%; 95% CI: 81-98), and 40 cases (11%) and 70 controls (27%) were partially vaccinated (VE: 70%; 95% CI: 50-82). A strongly protective effect of vaccination was found in all comorbidity subgroups. No ICU-admission or mortality were reported among fully vaccinated cases. Of unvaccinated cases, mortality was 10% and 19% was admitted at the ICU Conclusion: COVID-19 vaccination provides a strong protective effect against COVID-19 related hospital admission, in patients with and without comorbidity.

scholarly journals Effectiveness of mRNA-1273 against delta, mu, and other emerging variants of SARS-CoV-2: test negative case-control study

BMJ ◽  
2021 ◽  
pp. e068848
Author(s):  
Katia J Bruxvoort ◽  
Lina S Sy ◽  
Lei Qian ◽  
Bradley K Ackerson ◽  
Yi Luo ◽  
...  
Keyword(s):  
Hospital Admission ◽  
Case Control Study ◽  
Conditional Logistic Regression ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Specimen Collection ◽  
Negative Case ◽  
Delta Infection ◽  
Control Study ◽  
Dose Vaccine

Abstract Objectives To evaluate the effectiveness of the mRNA-1273 vaccine against SARS-CoV-2 variants and assess its effectiveness against the delta variant by time since vaccination. Design Test negative case-control study. Setting Kaiser Permanente Southern California (KPSC), an integrated healthcare system. Participants Adult KPSC members with a SARS-CoV-2 positive test sent for whole genome sequencing or a negative test from 1 March 2021 to 27 July 2021. Interventions Two dose or one dose vaccination with mRNA-1273 (Moderna covid-19 vaccine) ≥14 days before specimen collection versus no covid-19 vaccination. Main outcome measures Outcomes included infection with SARS-CoV-2 and hospital admission with covid-19. In pre-specified analyses for each variant type, test positive cases were matched 1:5 to test negative controls on age, sex, race/ethnicity, and specimen collection date. Conditional logistic regression was used to compare odds of vaccination among cases versus controls, with adjustment for confounders. Vaccine effectiveness was calculated as (1–odds ratio)×100%. Results The study included 8153 cases and their matched controls. Two dose vaccine effectiveness was 86.7% (95% confidence interval 84.3% to 88.7%) against infection with the delta variant, 98.4% (96.9% to 99.1%) against alpha, 90.4% (73.9% to 96.5%) against mu, 96-98% against other identified variants, and 79.9% (76.9% to 82.5%) against unidentified variants (that is, specimens that failed sequencing). Vaccine effectiveness against hospital admission with the delta variant was 97.5% (92.7% to 99.2%). Vaccine effectiveness against infection with the delta variant declined from 94.1% (90.5% to 96.3%) 14-60 days after vaccination to 80.0% (70.2% to 86.6%) 151-180 days after vaccination. Waning was less pronounced for non-delta variants. Vaccine effectiveness against delta infection was lower among people aged ≥65 years (75.2%, 59.6% to 84.8%) than those aged 18-64 years (87.9%, 85.5% to 89.9%). One dose vaccine effectiveness was 77.0% (60.7% to 86.5%) against infection with delta. Conclusions Two doses of mRNA-1273 were highly effective against all SARS-CoV-2 variants, especially against hospital admission with covid-19. However, vaccine effectiveness against infection with the delta variant moderately declined with increasing time since vaccination.

scholarly journals Vaccine effectiveness against COVID-19 hospitalization in adults in France: a test negative case control study

2021 ◽  
Author(s):  
Liem Binh Luong Nguyen ◽  
Rebecca Bauer ◽  
Zineb Lesieur ◽  
Florence Galtier ◽  
Xavier Duval ◽  
...  
Keyword(s):  
Case Control Study ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Negative Case ◽  
Control Study

scholarly journals Epidemiology, vaccine effectiveness, and risk factors for mortality for pneumococcal disease among hospitalised adults in Singapore: a case-control study

2020 ◽  
Author(s):  
Tyson Chan ◽  
Min Zhi Tay ◽  
Win Mar Kyaw ◽  
Angela Chow ◽  
Hanley J Ho
Keyword(s):  
Risk Factors ◽  
Pneumococcal Disease ◽  
Case Control Study ◽  
Pneumococcal Vaccination ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Adjusted Relative Risk ◽  
Factors Associated ◽  
Icu Admission ◽  
Control Study

Abstract Background: Streptococcus pneumoniae infections can lead to severe morbidity and mortality, especially in patients with invasive pneumococcal disease (IPD). This study evaluated factors associated with pneumococcal disease, pneumococcal vaccine effectiveness, and risk factors for all-cause mortality in hospitalised adults with pneumococcal disease in Singapore. Methods: Retrospective case-control study of patients tested for pneumococcal disease with streptococcal urinary antigen testing and at least one sterile site culture, during their admission to a tertiary hospital in Singapore from 2015-2017. Patients were defined as cases of IPD or non-IPD, or as controls, based on laboratory results and clinical diagnoses. Multivariable models were constructed to determine factors associated with IPD/non-IPD, and risk factors for mortality from pneumococcal disease. Vaccine effectiveness against IPD/non-IPD was estimated using a variation of the test-negative design. Results: We identified 496 pneumococcal disease cases, of whom 92 (18.5%) had IPD. The mean age of cases was 69.1±15.4yrs, and 65.5% were male. Compared with controls (N=9,181), IPD patients were younger (mean age 61.5±16.3yrs, vs 72.2±16.1yrs in controls; p<0.001) and with less co-morbidities [median Charlson’s score 1 (IQR 0-4), vs 3 (1-5) in controls; p<0.001]. IPD patients also had the highest proportions with intensive care unit (ICU) admission (20.7%), inpatient mortality (26.1%) and longest median length of stay [9 (IQR 8-17) days]. On multivariable analysis, IPD was negatively associated with prior pneumococcal vaccination (adjusted relative risk ratio=0.20, 95%CI 0.06–0.69; p=0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission, diagnosis of IPD, age ≥85yrs and Charlson’s score >3.Conclusion: Patients with pneumococcal disease (especially IPD) were younger and had less co-morbidities than controls, but had higher risk of severe clinical outcomes and mortality. Pneumococcal vaccination effectiveness against IPD was estimated to be about 80%, and should be encouraged among high-risk patients.

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 hospitalisation due to laboratory-confirmed influenza in children in England in the 2015–2016 influenza season – a test-negative case–control study

2019 ◽  
Vol 147 ◽  
Author(s):  
N. L. Boddington ◽  
F. Warburton ◽  
H. Zhao ◽  
N. Andrews ◽  
J. Ellis ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Case Control Study ◽  
Risk Group ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Age Group ◽  
Sample Collection ◽  
Live Attenuated Vaccine ◽  
Negative Case ◽  
Control Study

AbstractEngland has recently started a new paediatric influenza vaccine programme using a live-attenuated influenza vaccine (LAIV). There is uncertainty over how well the vaccine protects against more severe end-points. A test-negative case–control study was used to estimate vaccine effectiveness (VE) in vaccine-eligible children aged 2–16 years of age in preventing laboratory-confirmed influenza hospitalisation in England in the 2015–2016 season using a national sentinel laboratory surveillance system. Logistic regression was used to estimate the VE with adjustment for sex, risk-group, age group, region, ethnicity, deprivation and month of sample collection. A total of 977 individuals were included in the study (348 cases and 629 controls). The overall adjusted VE for all study ages and vaccine types was 33.4% (95% confidence interval (CI) 2.3–54.6) after adjusting for age group, sex, index of multiple deprivation, ethnicity, region, sample month and risk group. Risk group was shown to be an important confounder. The adjusted VE for all influenza types for the live-attenuated vaccine was 41.9% (95% CI 7.3–63.6) and 28.8% (95% CI −31.1 to 61.3) for the inactivated vaccine. The study provides evidence of the effectiveness of influenza vaccination in preventing hospitalisation due to laboratory-confirmed influenza in children in 2015–2016 and continues to support the rollout of the LAIV childhood programme.

scholarly journals Effectiveness of the CoronaVac vaccine in the elderly population during a P.1 variant-associated epidemic of COVID-19 in Brazil: A test-negative case-control study

2021 ◽  
Author(s):  
Otavio T. Ranzani ◽  
Matt Hitchings ◽  
Murilo Dorion Neto ◽  
Tatiana Lang D'Agostini ◽  
Regiane Cardoso de Paula ◽  
...  
Keyword(s):  
Dose Regimen ◽  
Elderly Population ◽  
Case Control Study ◽  
The Elderly ◽  
Case Control ◽  
Vaccine Effectiveness ◽  
Rt Pcr ◽  
Paulo State ◽  
Negative Case ◽  
Control Study

Background Mass vaccination is being used in response to coronavirus disease (COVID-19) epidemics, including those driven by emerging variants of concern. We evaluated the effectiveness of the inactivated whole-virus vaccine, CoronaVac, against symptomatic COVID-19 in the elderly population of Sao Paulo State, Brazil during widespread circulation of the P.1 variant. Methods We conducted a test-negative, case-control study of adults >=70 years of age from Sao Paulo State from January 17 to April 29, 2021, during which vaccination with a two-dose regimen of CoronaVac was implemented. We identified RT-PCR-confirmed COVID-19 cases and controls who had a symptomatic illness with a negative RT-PCR test from national surveillance and state vaccination databases. Controls were pair-matched to cases by age category, sex, race, municipality, prior COVID-19 status, and date of RT-PCR testing. We estimated vaccine effectiveness, adjusted for age and comorbidities, using conditional logistic regression. Findings We selected 7,950 matched pairs with a mean age of 76 years from 26,433 COVID-19 cases and 17,622 test-negative controls. Adjusted vaccine effectiveness was 18.2% (95% CI, 0.0 to 33.2) and 41.6% (95% CI, 26.9 to 53.3) in the period 0-13 and >=14 days, respectively, after the 2nd dose. Administration of a single vaccine dose was not associated with reduced odds of COVID-19. Vaccine effectiveness >=14 days after the 2nd dose declined with increasing age and was 61.8% (95% CI 34.8 to 77.7), 48.9% (95% CI 23.3 to 66.0) and 28.0% (95% CI 0.6 to 47.9) among individuals 70-74, 75-79 and >=80 years of age, respectively (p-interaction = 0.05). Interpretation CoronaVac was 42% effective in the real-world setting of extensive P.1 transmission, but significant protection was not observed until completion of the two-dose regimen. These findings underscore the need to maintain non-pharmaceutical interventions when mass vaccination with CoronaVac is used as part of an epidemic response. Funding Pan American Health Organization

Sign in / Sign up

Export Citation Format

Share Document