scholarly journals BNT162b2 vaccine effectiveness in preventing asymptomatic infection with SARS-CoV-2 virus: a nationwide historical cohort study

2021 ◽  
Author(s):  
Galia Zacay ◽  
David Shasha ◽  
Ronen Bareket ◽  
Itai Kadim ◽  
Fabienne Hershkowitz Sikron ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Health Maintenance Organization ◽  
Vaccine Dose ◽  
Asymptomatic Infection ◽  
Vaccine Effectiveness ◽  
Study Cohort ◽  
Infection Rates ◽  
Symptomatic Infection ◽  
Historical Cohort ◽  
Health Maintenance

Abstract Background There is strong evidence regarding the efficacy and effectiveness of BNT162b2 vaccine in preventing symptomatic infection with SARS-CoV-2 virus. There is a relative paucity of data regarding effectiveness in prevention of asymptomatic infection. Methods In this real-world observational study, we identified a sub-population of individuals in a large health maintenance organization who were repeatedly tested for SARS-CoV-2 infection by PCR. We included these individuals in the study cohort, and compared those who were vaccinated with BNT162b2 mRNA vaccine to the unvaccinated ones. A positive SARS-CoV-2 PCR test result was used as the outcome. Follow-up period was from January 1,2021 until February 11, 2021. Findings 6,286 individuals were included in the cohort. Seven days following the second vaccine dose, a rate of six positive PCR tests per 10,000 person-days was recorded, compared with a rate of 53 positive tests per 10,000 person-days for the unvaccinated group. The estimated vaccine effectiveness against infection with SARS-CoV-2 virus after two vaccine doses was 89% (95% confidence interval 82%-94%). The estimated effectiveness two weeks following the first vaccine dose was 61% (95% confidence interval 49%-71%). Interpretation In this study, vaccination with BNT162b2 reduced infection rates among individuals who underwent screening by frequent SARS-CoV-2 PCR testing. Using a cohort of frequently tested individuals reduced the indication bias for the PCR testing, which enabled estimation of infection rates. Funding This study received no funding.

scholarly journals Effectiveness of COVID-19 vaccines against SARS-CoV-2 infection with the Delta (B.1.617.2) variant: second interim results of a living systematic review and meta-analysis, 1 January to 25 August 2021

2021 ◽  
Vol 26 (41) ◽  
Author(s):  
Thomas Harder ◽  
Wiebe Külper-Schiek ◽  
Sarah Reda ◽  
Marina Treskova-Schwarzbach ◽  
Judith Koch ◽  
...  
Keyword(s):  
Systematic Review ◽  
Confidence Interval ◽  
Meta Analysis ◽  
Asymptomatic Infection ◽  
Vaccine Effectiveness ◽  
Symptomatic Infection ◽  
Alpha Variant

The Delta variant has become the dominant strain of SARS-CoV-2. We summarised the evidence on COVID-19 vaccine effectiveness (VE) identified in 17 studies that investigated VE against different endpoints. Pooled VE was 63.1% (95% confidence interval (CI): 40.9–76.9) against asymptomatic infection, 75.7% (95% CI: 69.3–80.8) against symptomatic infection and 90.9% (95% CI: 84.5–94.7) against hospitalisation. Compared with the Alpha variant, VE against mild outcomes was reduced by 10–20%, but fully maintained against severe COVID-19.

scholarly journals Estimates of Single Dose and Full Dose BNT162b2 Vaccine Effectiveness among USAF Academy cadets, 1 Mar - 1 May 2021

2021 ◽  
Author(s):  
Douglas P Wickert ◽  
Erin Almand ◽  
Christopher A Cullenbine ◽  
Odaro J Huckstep ◽  
Joseph Rohrer ◽  
...  
Keyword(s):  
Young Adults ◽  
Single Dose ◽  
Confidence Interval ◽  
Military Training ◽  
Vaccine Dose ◽  
Infection Risk ◽  
Vaccine Effectiveness ◽  
Training Environment ◽  
Fold Reduction ◽  
University Setting

Beginning in early March 2021 and continuing through May 2021, the USAF Academy began vaccinating cadets for protection against the SARS-CoV-2 virus with the BNT162b2 (Pfizer-BioNTech) mRNA vaccine. During this period, vaccination of the almost 4200 cadet population increased from 3% to 85% and prevalence of COVID-19 in the cadet population was constant at approximately 0.4% as indicated by weekly surveillance testing. In this study, vaccine effectiveness at preventing infection is estimated by comparing infection risk as a function of time since vaccination. A statistically significant four-fold reduction in infection risk was observed 14 days after the first vaccine dose and an eleven-fold reduction in infection risk was observed in fully vaccinated cadets. Overall, the Pfizer-BioNTech vaccine was 91% (95% confidence interval = 55-99%) effective at preventing infection in healthy young adults (17-26 years of age) in a university setting and military training environment.

scholarly journals Waning of BNT162b2 vaccine protection against SARS-CoV-2 infection in Qatar

2021 ◽  
Author(s):  
Hiam Chemaitelly ◽  
Patrick Tang ◽  
Mohammad Rubayet Hasan ◽  
Sawsan AlMukdad ◽  
HADI M. YASSINE ◽  
...  
Keyword(s):  
Case Control Study ◽  
Asymptomatic Infection ◽  
Mass Scale ◽  
Vaccine Effectiveness ◽  
Symptomatic Infection ◽  
Vaccine Protection ◽  
The Third ◽  
Negative Case ◽  
Protection Against Infection ◽  
Control Study

BACKGROUND: Waning of vaccine protection against SARS-CoV-2 infection or COVID-19 disease is a concern. This study investigated persistence of BNT162b2 (Pfizer-BioNTech) vaccine effectiveness against infection and disease in Qatar, where the Beta and Delta variants have dominated incidence and PCR testing is done at a mass scale. METHODS: A matched test-negative, case-control study design was used to estimate vaccine effectiveness against SARS-CoV-2 infection and against any severe, critical, or fatal COVID-19 disease, between January 1, 2021 to August 15, 2021. RESULTS: Estimated BNT162b2 effectiveness against any infection, asymptomatic or symptomatic, was negligible for the first two weeks after the first dose, increased to 36.5% (95% CI: 33.1-39.8) in the third week after the first dose, and reached its peak at 72.1% (95% CI: 70.9-73.2) in the first five weeks after the second dose. Effectiveness declined gradually thereafter, with the decline accelerating ≥15 weeks after the second dose, reaching diminished levels of protection by the 20th week. Effectiveness against symptomatic infection was higher than against asymptomatic infection, but still waned in the same fashion. Effectiveness against any severe, critical, or fatal disease increased rapidly to 67.7% (95% CI: 59.1-74.7) by the third week after the first dose, and reached 95.4% (95% CI: 93.4-96.9) in the first five weeks after the second dose, where it persisted at about this level for six months. CONCLUSIONS: BNT162b2-induced protection against infection appears to wane rapidly after its peak right after the second dose, but it persists at a robust level against hospitalization and death for at least six months following the second dose.  

scholarly journals Effectiveness of COVID-19 vaccines in preventing SARS-CoV-2 infection and hospitalisation, Navarre, Spain, January to April 2021

2021 ◽  
Vol 26 (21) ◽  
Author(s):  
Iván Martínez-Baz ◽  
Ana Miqueleiz ◽  
Itziar Casado ◽  
Ana Navascués ◽  
Camino Trobajo-Sanmartín ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Vaccine Effectiveness ◽  
Symptomatic Infection ◽  
Dose Vaccine ◽  
Close Contacts

COVID-19 vaccine effectiveness was evaluated in close contacts of cases diagnosed during January–April 2021. Among 20,961 contacts, 7,240 SARS-CoV-2 infections were confirmed, with 5,467 being symptomatic and 559 leading to hospitalisations. Non-brand-specific one and two dose vaccine effectiveness were respectively, 35% (95% confidence interval (CI): 25 to 44) and 66% (95% CI: 57 to 74) against infections, 42% (95% CI: 31 to 52) and 82% (95% CI: 74 to 88) against symptomatic infection, and 72% (95% CI: 47 to 85) and 95% (95% CI: 62 to 99) against COVID-19 hospitalisation. The second dose significantly increased effectiveness. Findings support continuing complete vaccination.

scholarly journals Waning immunity of the BNT162b2 vaccine: A nationwide study from Israel

2021 ◽  
Author(s):  
Yair Goldberg ◽  
Micha Mandel ◽  
Yinon M. Bar-On ◽  
Omri Bodenheimer ◽  
Laurence Freedman ◽  
...  
Keyword(s):  
Vaccination Campaign ◽  
Age Groups ◽  
Vaccine Dose ◽  
Vaccine Effectiveness ◽  
National Database ◽  
Test Results ◽  
Infection Rates ◽  
Policy Makers ◽  
Mass Vaccination Campaign ◽  
Waning Immunity

ABSTRACTBackgroundStarting December 2020, Israel began a mass vaccination campaign against coronavirus administering the Pfizer BNT162b2 vaccine, which led to a sharp curtailing of the outbreak. After a period with almost no SARS-CoV-2 infections, a resurgent COVID-19 outbreak initiated mid June 2021. Possible reasons for the breakthrough were reduced vaccine effectiveness against the Delta variant, and waning immunity. The aim of this study was to quantify the extent of waning immunity using Israel’s national-database.MethodsData on all PCR positive test results between July 11-31, 2021 of Israeli residents who became fully vaccinated before June 2021 were used in this analysis. Infection rates and severe COVID-19 outcomes were compared between individuals who were vaccinated in different time periods using a Poisson regression, stratifying by age group and adjusting for possible confounding factors.ResultsThe rates of both documented SARS-CoV-2 infections and severe COVID-19 exhibit a statistically significant increase as time from second vaccine dose elapsed. Elderly individuals (60+) who received their second dose in March 2021 were 1.6 (CI: [1.3, 2]) times more protected against infection and 1.7 (CI: [1.0, 2.7]) times more protected against severe COVID-19 compared to those who received their second dose in January 2021. Similar results were found for different age groups.ConclusionsThese results indicate a strong effect of waning immunity in all age groups after six months. Quantifying the effect of waning immunity on vaccine effectiveness is critical for policy makers worldwide facing the dilemma of administering booster vaccinations.

Development and Validation of an Immunization Tracking System in a Large Health Maintenance Organization

1993 ◽  
Vol 9 (2) ◽  
pp. 96-100 ◽  
Author(s):  
Thomas Payne ◽  
Susan Kanvik ◽  
Richard Seward ◽  
Doug Beeman ◽  
Angela Salazar ◽  
...  
Keyword(s):  
Tracking System ◽  
Health Maintenance Organization ◽  
Health Maintenance ◽  
Development And Validation

scholarly journals The Prognostic Role of LRIG Proteins in Endometrial Cancer

Cancers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1361
Author(s):  
Zoia Razumova ◽  
Husam Oda ◽  
Igor Govorov ◽  
Eva Lundin ◽  
Ellinor Östensson ◽  
...  
Keyword(s):  
Overall Survival ◽  
Endometrial Cancer ◽  
Prognostic Factor ◽  
Confidence Interval ◽  
Initial Study ◽  
Surface Proteins ◽  
University Hospital ◽  
Study Cohort ◽  
Risk Of Death

Endometrial cancer (EC) is the most common gynecologic malignancy in Sweden and it has various prognostic factors. The LRIG family is a group of three integral surface proteins with a similar domain organization. The study aimed to explore LRIG family as prognostic factor proteins in EC. The initial study cohort included 100 women with EC who were treated at the Department of Women’s and Children’s Health, Karolinska University Hospital Solna, between 2007 and 2012. We assessed the associations between LRIG protein expression and type, grade, and stage of EC, as well as progression-free and overall survival. Immunohistochemistry results revealed that most women in the analytical sample had >50% LRIG1-, LRIG2- and LRIG3-positive cells. A statistically significant association was observed between having a high number of LRIG3-positive cells and superior overall survival (incidence rate ratio = 0.977; 95% confidence interval: 0.958–0.996, p = 0.019). Moreover, positive LRIG3 staining of the cell membrane was associated with reducing in the risk of death (hazard ratio = 0.23; 95% confidence interval: 0.09–0.57). Our results show that LRIG3 expression might be a prognostic factor in EC. The role of LRIG1 and LRIG2 expression remains to be further investigated.

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