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1.
Acta Med Acad ; 51(2): 134-146, 2022 Aug.
Article in English | MEDLINE | ID: covidwho-2093996

ABSTRACT

Herein, we present a bird's eye view of common observational study designs utilized for measurement of vaccine effectiveness. Assessing vaccines effectiveness is an integral part of vaccine research, particularly for the newly developed vaccines. A cohort study is prospective, directing from an exposure to one or more outcomes. The design is the best method to ascertain the attack rate of an infectious disease. A traditional case-control study is retrospective, directing from a given outcome to one or more exposures. The design cannot provide the relative risk, but it can provide the odds ratio, which is a good estimation of the relative risk when the attack rate is low. Critically depending on laboratory test results and performance, the test-negative case-control study design is another type of observational study commonly used nowadays for the evaluation of the vaccine effectiveness. Comparing to cohort and traditional case-control designs, conducting a test-negative case-control study is relatively cheaper and faster. Herein, we describe each of the above-mentioned study designs through examples generated by a Monte-Carlo simulation program assuming real-world conditions. CONCLUSION: The simulation shows that regardless of the study design employed, the diagnostic test specificity is of utmost importance in providing a valid estimate of the vaccine effectiveness.


Subject(s)
Vaccine Efficacy , Vaccines , Humans , Case-Control Studies , Cohort Studies , Retrospective Studies , Prospective Studies
2.
Scand J Trauma Resusc Emerg Med ; 29(1): 155, 2021 Oct 30.
Article in English | MEDLINE | ID: covidwho-2098402

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a highly contagious airborne virus inducing pandemic coronavirus disease 2019 (COVID-19). This is most relevant for medical staff working under harmful conditions in emergencies often dealing with patients and an undefined SARS-CoV-2 status. We aimed to measure the effect of high-class filtering facepieces (FFP) in emergency medical service (EMS) staff by analyzing seroprevalence and history of positive polymerase chain reaction (PCR) for SARS-CoV-2. METHOD: This observational cohort study included workers in EMS, who were compared with hospital staff (HS) and staff, which was not directly involved in patient care (NPC). All direct patient contacts of EMS workers were protected by FFP2/N95 (filtering face piece protection class 2/non-oil-based particulates filter efficiency 95%) masks, whereas HS was protected by FFP2/N95 exclusively when a patient had a proven or suspected SARS-CoV-2 infection. NPC was not protected by higher FFP. The seroprevalence of SARS-CoV-2 antibodies was analyzed by immunoassay by end of 12/2020 together with the history of a positive PCR. In addition, a self-assessment was performed regarding the quantity of SARS-CoV-2 positive contacts, about flu symptoms and personal belief of previous COVID-19 infections. RESULTS: The period in which contact to SARS-CoV-2 positive patients has been possible was 10 months (March to December 2020)-with 54,681 patient contacts documented for EMS-either emergencies (n = 33,241) or transportation services (n = 21,440). Seven hundred-thirty (n = 730) participants were included into the study (n = EMS: 325, HS: 322 and NPC: 83). The analysis of the survey showed that the exposure to patients with an unknown and consecutive positive SARS-CoV-2 result was significantly higher for EMS when compared to HS (EMS 55% vs. HS 30%, p = 0.01). The incidence of a SARS-CoV-2 infection in our cohort was 1.2% (EMS), 2.2% (HS) and 2.4% (NPC) within the three groups (ns) and lowest in EMS. Furthermore, the belief of previous COVID-19 was significant higher in EMS (19% vs. 10%), CONCLUSION: The consistent use of FFP2/N95 in EMS is able to prevent work-related SARS-CoV-2 infections in emergency situations. The significance of physical airway protection in exposed medical staff is still relevant especially under the aspect of new viral variants and unclear effectiveness of new vaccines.


Subject(s)
COVID-19 , Emergencies , Cohort Studies , Health Personnel , Humans , SARS-CoV-2 , Seroepidemiologic Studies
3.
Scand J Trauma Resusc Emerg Med ; 28(1): 66, 2020 Jul 13.
Article in English | MEDLINE | ID: covidwho-2098371

ABSTRACT

BACKGROUND: There is a need for validated clinical risk scores to identify patients at risk of severe disease and to guide decision-making during the covid-19 pandemic. The National Early Warning Score 2 (NEWS2) is widely used in emergency medicine, but so far, no studies have evaluated its use in patients with covid-19. We aimed to study the performance of NEWS2 and compare commonly used clinical risk stratification tools at admission to predict risk of severe disease and in-hospital mortality in patients with covid-19. METHODS: This was a prospective cohort study in a public non-university general hospital in the Oslo area, Norway, including a cohort of all 66 patients hospitalised with confirmed SARS-CoV-2 infection from the start of the pandemic; 13 who died during hospital stay and 53 who were discharged alive. Data were collected consecutively from March 9th to April 27th 2020. The main outcome was the ability of the NEWS2 score and other clinical risk scores at emergency department admission to predict severe disease and in-hospital mortality in covid-19 patients. We calculated sensitivity and specificity with 95% confidence intervals (CIs) for NEWS2 scores ≥5 and ≥ 6, quick Sequential Organ Failure Assessment (qSOFA) score ≥ 2, ≥2 Systemic Inflammatory Response Syndrome (SIRS) criteria, and CRB-65 score ≥ 2. Areas under the curve (AUCs) for the clinical risk scores were compared using DeLong's test. RESULTS: In total, 66 patients (mean age 67.9 years) were included. Of these, 23% developed severe disease. In-hospital mortality was 20%. Tachypnoea, hypoxemia and confusion at admission were more common in patients developing severe disease. A NEWS2 score ≥ 6 at admission predicted severe disease with 80.0% sensitivity and 84.3% specificity (Area Under the Curve (AUC) 0.822, 95% CI 0.690-0.953). NEWS2 was superior to qSOFA score ≥ 2 (AUC 0.624, 95% CI 0.446-0.810, p < 0.05) and other clinical risk scores for this purpose. CONCLUSION: NEWS2 score at hospital admission predicted severe disease and in-hospital mortality, and was superior to other widely used clinical risk scores in patients with covid-19.


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Early Warning Score , Hospital Mortality , Patient Admission , Pneumonia, Viral/epidemiology , Adult , Aged , Aged, 80 and over , COVID-19 , Cohort Studies , Female , Humans , Male , Middle Aged , Norway/epidemiology , Pandemics , Risk Assessment , SARS-CoV-2 , Sensitivity and Specificity , Severity of Illness Index
4.
Scand J Trauma Resusc Emerg Med ; 30(1): 12, 2022 Feb 19.
Article in English | MEDLINE | ID: covidwho-2098408

ABSTRACT

BACKGROUND: Given that Swedish authorities have been widely viewed as having practiced an unusual approach to the COVID-19 pandemic and given that Sweden is notable for a low incidence of trauma, we wanted to learn how the pandemic may have affected the number of trauma admissions in Sweden. METHODS: We conducted a retrospective cohort study based on the Swedish trauma registry (Svenska Traumaregistret). The study period was March 1, 2020 to June 30, 2020. As a basis for comparison, the record for the same time during the previous year, 2019 was used. RESULTS: During the four months of the first wave of COVID-19, 2020 there was a decline of 24.2% in the total number of trauma patients in Sweden. There was no significant change in 30-day mortality rates, 4.7% 2019 and 5.1% 2020, (p = 0.30). The number of injuries per patient was higher during the pandemic 3.8 injuries 2019 and 4.1 injuries 2020 (p = 0.02). The NISS 6, 2019 and 8, 2020 was higher during the pandemic. CONCLUSIONS: As a consequence of what were seen by many as all too lenient actions taken to deal with COVID-19 in Sweden during spring 2020, there was still a reduction in trauma admissions most likely due to an adherence to the voluntary recommendations, the reduction was not as prominent as what was seen in many countries with harsher restrictions and lockdowns.


Subject(s)
COVID-19 , Pandemics , Cohort Studies , Communicable Disease Control , Humans , Retrospective Studies , SARS-CoV-2 , Sweden/epidemiology
5.
Eur Respir Rev ; 31(166)2022 Dec 31.
Article in English | MEDLINE | ID: covidwho-2098298

ABSTRACT

BACKGROUND: As mortality from coronavirus disease 2019 (COVID-19) is strongly age-dependent, we aimed to identify population subgroups at an elevated risk for adverse outcomes from COVID-19 using age-/gender-adjusted data from European cohort studies with the aim to identify populations that could potentially benefit from booster vaccinations. METHODS: We performed a systematic literature review and meta-analysis to investigate the role of underlying medical conditions as prognostic factors for adverse outcomes due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), including death, hospitalisation, intensive care unit (ICU) admission and mechanical ventilation within three separate settings (community, hospital and ICU). Cohort studies that reported at least age and gender-adjusted data from Europe were identified through a search of peer-reviewed articles published until 11 June 2021 in Ovid Medline and Embase. Results are presented as odds ratios with 95% confidence intervals and absolute risk differences in deaths per 1000 COVID-19 patients. FINDINGS: We included 88 cohort studies with age-/gender-adjusted data from 6 653 207 SARS-CoV-2 patients from Europe. Hospital-based mortality was associated with high and moderate certainty evidence for solid organ tumours, diabetes mellitus, renal disease, arrhythmia, ischemic heart disease, liver disease and obesity, while a higher risk, albeit with low certainty, was noted for chronic obstructive pulmonary disease and heart failure. Community-based mortality was associated with a history of heart failure, stroke, diabetes and end-stage renal disease. Evidence of high/moderate certainty revealed a strong association between hospitalisation for COVID-19 and solid organ transplant recipients, sleep apnoea, diabetes, stroke and liver disease. INTERPRETATION: The results confirmed the strong association between specific prognostic factors and mortality and hospital admission. Prioritisation of booster vaccinations and the implementation of nonpharmaceutical protective measures for these populations may contribute to a reduction in COVID-19 mortality, ICU and hospital admissions.


Subject(s)
COVID-19 , Hospitalization , Intensive Care Units , Humans , Cohort Studies , COVID-19/mortality , COVID-19/therapy , Hospitalization/statistics & numerical data , Prognosis , Europe/epidemiology , Male , Female
6.
J Infect Dis ; 226(9): 1556-1561, 2022 Nov 01.
Article in English | MEDLINE | ID: covidwho-2097370

ABSTRACT

BACKGROUND: To inform public health policy, it is critical to monitor coronavirus disease 2019 vaccine effectiveness (VE), including against acquiring infection. METHODS: We estimated VE using self-reported vaccination in a retrospective cohort of repeat blood donors who donated during the first half of 2021, and we demonstrated a viable approach for monitoring VE via serological surveillance. RESULTS: Using Poisson regression, we estimated an overall VE of 88.8% (95% confidence interval, 86.2-91.1), adjusted for demographic covariates and variable baseline risk. CONCLUSIONS: The time since first reporting vaccination, age, race and/or ethnicity, region, and calendar time were statistically significant predictors of incident infection.


Subject(s)
COVID-19 Vaccines , COVID-19 , Humans , United States , Retrospective Studies , Blood Donors , Vaccine Efficacy , Cohort Studies
8.
Rev Clin Esp (Barc) ; 222(8): 468-478, 2022 10.
Article in English | MEDLINE | ID: covidwho-2095943

ABSTRACT

OBJECTIVE: Various studies have identified factors associated with risk of mortality in patients with SARS-CoV-2 infection. However, their sample size has often been limited and their results partially contradictory. This study evaluated factors associated with COVID-19 mortality in the population of Madrid over 75 years of age, in infected patients, and in hospitalized patients up to January 2021. PATIENTS AND METHODS: This population-based cohort study analyzed all residents of the Community of Madrid born before January 1, 1945 who were alive as of December 31, 2019. Demographic and clinical data were obtained from primary care electronic medical records (PC-Madrid), data on hospital admissions from the Conjunto Mínimo Básico de Datos (CMBD, Minimum Data Set), and data on mortality from the Índice Nacional de Defunciones (INDEF, National Death Index). Data on SARS-CoV-2 infection, hospitalization, and death were collected from March 1, 2020 to January 31, 2021. RESULTS: A total of 587,603 subjects were included in the cohort. Of them, 41,603 (7.1%) had confirmed SARS-CoV-2 infection, of which 22,362 (53.7% of the infected individuals) were hospitalized and 11,251 (27%) died. Male sex and age were the factors most closely associated with mortality, though many comorbidities also had an influence. The associations were stronger in the analysis of the total population than in the analysis of infected or hospitalized patients. Mortality among hospitalized patients was lower during the second wave (33.4%) than during the first wave (41.2%) of the pandemic. CONCLUSION: Age, sex, and numerous comorbidities are associated with risk of death due to COVID-19. Mortality in hospitalized patients declined notably after the first wave of the pandemic.


Subject(s)
COVID-19 , SARS-CoV-2 , Cohort Studies , Hospitalization , Humans , Male , Pandemics
9.
J Am Coll Cardiol ; 80(20): 1900-1908, 2022 Nov 15.
Article in English | MEDLINE | ID: covidwho-2095536

ABSTRACT

BACKGROUND: Postmarketing evaluations have linked myocarditis to COVID-19 mRNA vaccines. However, few population-based analyses have directly compared the safety of the 2 mRNA COVID-19 vaccines. OBJECTIVES: This study aimed to compare the risk of myocarditis, pericarditis, and myopericarditis between BNT162b2 and mRNA-1273. METHODS: We used data from the British Columbia COVID-19 Cohort (BCC19C), a population-based cohort study. The exposure was the second dose of an mRNA vaccine. The outcome was diagnosis of myocarditis, pericarditis, or myopericarditis during a hospitalization or an emergency department visit within 21 days of the second vaccination dose. We performed multivariable logistic regression to assess the association between vaccine product and the outcomes of interest. RESULTS: The rates of myocarditis and pericarditis per million second doses were higher for mRNA-1273 (n = 31, rate 35.6; 95% CI: 24.1-50.5; and n = 20, rate 22.9; 95% CI: 14.0-35.4, respectively) than BNT162b2 (n = 28, rate 12.6; 95% CI: 8.4-18.2 and n = 21, rate 9.4; 95% CI: 5.8-14.4, respectively). mRNA-1273 vs BNT162b2 had significantly higher odds of myocarditis (adjusted OR [aOR]: 2.78; 95% CI: 1.67-4.62), pericarditis (aOR: 2.42; 95% CI: 1.31-4.46) and myopericarditis (aOR: 2.63; 95% CI: 1.76-3.93). The association between mRNA-1273 and myocarditis was stronger for men (aOR: 3.21; 95% CI: 1.77-5.83) and younger age group (18-39 years; aOR: 5.09; 95% CI: 2.68-9.66). CONCLUSIONS: Myocarditis/pericarditis following mRNA COVID-19 vaccines is rare, but we observed a 2- to 3-fold higher odds among individuals who received mRNA-1273 vs BNT162b2. The rate of myocarditis following mRNA-1273 receipt is highest among younger men (age 18-39 years) and does not seem to be present at older ages. Our findings may have policy implications regarding the choice of vaccine offered.


Subject(s)
COVID-19 Vaccines , COVID-19 , Myocarditis , Pericarditis , Adolescent , Adult , Humans , Male , Young Adult , 2019-nCoV Vaccine mRNA-1273 , BNT162 Vaccine , Cohort Studies , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Myocarditis/epidemiology , Myocarditis/etiology , Myocarditis/diagnosis , Pericarditis/epidemiology , Pericarditis/etiology , Pericarditis/diagnosis , Vaccination , Vaccines
10.
Epidemiol Prev ; 46(4): 250-258, 2022.
Article in English | MEDLINE | ID: covidwho-2091260

ABSTRACT

OBJECTIVES: to evaluate immunogenicity and effectiveness of BNT162b2 COVID-19 vaccine in a cohort of healthcare workers (HCWs). DESIGN: cohort study. SETTING AND PARTICIPANTS: in a hospital in Milan (Lombardy Region, Northern Italy) HCWs without ("negative cohort") and with ("positive cohort") history of SARS-CoV-2 infection or elevated serum antibody before the vaccination campaign (27.12.2020) were included. Data collection and follow-up covered the period 27.12.2020-13.05.2022. MAIN OUTCOMES MEASURES: 1. serum anti-spike-1 (anti-S1) antibody levels after vaccination; 2. vaccine effectiveness (VE) against SARS-CoV-2 infections (either symptomatic or not) in the negative cohort. Data on infections were extracted from multiple sources (laboratory, accident reports, questionnaires). Vaccination was treated as a time-dependent variable. Using unvaccinated person-time as reference, hazard ratios (HR) of infections and 95% confidence intervals (95%CI) were calculated with a Cox regression model adjusted for gender, age, and occupation. VE was calculated as (1 - HR)×100. RESULTS: 5,596 HCWs were included, 4,771 in the negative and 825 in the positive cohort. In both cohorts, serum anti-S1 antibodies were high one months after the second dose, halved after six months, and returned to high levels after the third dose. In the negative cohort, 1,401 SARS-CoV-2 infections were identified. VE was 70% (95%CI 54-80; 46 infected) in the first four months after the second dose and later declined to 16% (95%CI 0-43; 97 infected). After the third dose, VE increased to 57% (95%CI 35-71; 61 infected) in the first month but rapidly declined over time, particularly after three months (24% in the fourth month and 1% afterwards). The number of infections avoided by vaccination was estimated to be 643 (95%CI 236-1,237). CONCLUSIONS: in spite of rapidly declining effectiveness, vaccination helped to avoid several hundred infections in the considered hospital.


Subject(s)
BNT162 Vaccine , COVID-19 , Humans , Cohort Studies , COVID-19 Vaccines , COVID-19/epidemiology , COVID-19/prevention & control , Italy/epidemiology , SARS-CoV-2 , Health Personnel
11.
Pediatrics ; 150(5)2022 11 01.
Article in English | MEDLINE | ID: covidwho-2089495

ABSTRACT

OBJECTIVES: To evaluate outcomes of neonates born to mothers with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy, the dynamics of placental transfer of maternal antibodies, and its persistence during infancy. METHODS: Cohort study enrolling neonates born to mothers with SARS-CoV-2 infection in pregnancy. All infants were evaluated at birth. Those born to women with infection onset within 2 weeks before delivery were excluded from further analyses. Remaining infants underwent cerebral and abdominal ultrasound, fundoscopy evaluation, and were enrolled in a 12 month follow-up. Qualitative immunoglobulin G (IgG)/immunoglobulin M and quantitative IgG to S1/S2 subunits of spike protein were assessed in mother-neonate dyads within 48 hours postdelivery and during follow-up. RESULTS: Between April 2020 and April 2021, 130 of 2745 (4.7%) neonates were born to mothers with SARS-CoV-2 infection in pregnancy, with 106 of 130 infections diagnosed before 2 weeks before delivery. Rates of preterm and cesarean delivery were comparable between women with and without infection (6% vs 8%, P = .57; 22% vs 32%, P = .06). No clinical or instrumental abnormalities were detected at birth or during follow-up. There was a positive correlation between maternal and neonatal SARS-CoV-2 IgG levels (r = 0.81, P < .001). Transplacental transfer ratio was higher after second-trimester maternal infections as compared with first and third trimester (P = .03). SARS-CoV-2 IgG level progressively decreased in all infants, with 89 of 92 (97%) infants seronegative at 6 months of age. CONCLUSIONS: Clinical outcomes were favorable in all infants. Matching peak IgG level after infection and higher IgG transplacental transfer might result in the most durable neonatal passive immunity.


Subject(s)
COVID-19 , Pregnancy Complications, Infectious , Infant, Newborn , Infant , Female , Pregnancy , Humans , SARS-CoV-2 , Pregnancy Complications, Infectious/diagnosis , Infectious Disease Transmission, Vertical , Cohort Studies , Placenta , Immunoglobulin M , Immunoglobulin G
12.
CMAJ ; 194(14): E513-E523, 2022 04 11.
Article in English | MEDLINE | ID: covidwho-2089467

ABSTRACT

BACKGROUND: SARS-CoV-2 infection can lead to multisystem inflammatory syndrome in children (MIS-C). We sought to investigate risk factors for admission to the intensive care unit (ICU) and explored changes in disease severity over time. METHODS: We obtained data from chart reviews of children younger than 18 years with confirmed or probable MIS-C who were admitted to 15 hospitals in Canada, Iran and Costa Rica between Mar. 1, 2020, and Mar. 7, 2021. Using multivariable analyses, we evaluated whether admission date and other characteristics were associated with ICU admission or cardiac involvement. RESULTS: Of 232 children with MIS-C (median age 5.8 yr), 130 (56.0%) were male and 50 (21.6%) had comorbidities. Seventy-three (31.5%) patients were admitted to the ICU but none died. We observed an increased risk of ICU admission among children aged 13-17 years (adjusted risk difference 27.7%, 95% confidence interval [CI] 8.3% to 47.2%), those aged 6-12 years (adjusted risk difference 25.2%, 95% CI 13.6% to 36.9%) or those with initial ferritin levels greater than 500 µg/L (adjusted risk difference 18.4%, 95% CI 5.6% to 31.3%). Children admitted to hospital after Oct. 31, 2020, had numerically higher rates of ICU admission (adjusted risk difference 12.3%, 95% CI -0.3% to 25.0%) and significantly higher rates of cardiac involvement (adjusted risk difference 30.9%, 95% CI 17.3% to 44.4%). At Canadian sites, the risk of ICU admission was significantly higher for children admitted to hospital between December 2020 and March 2021 than those admitted between March and May 2020 (adjusted risk difference 25.3%, 95% CI 6.5% to 44.0%). INTERPRETATION: We observed that age and higher ferritin levels were associated with more severe MIS-C. We observed greater severity of MIS-C later in the study period. Whether emerging SARS-CoV-2 variants pose different risks of severe MIS-C needs to be determined.


Subject(s)
COVID-19 , Connective Tissue Diseases , COVID-19/complications , COVID-19/epidemiology , Canada/epidemiology , Child , Child, Preschool , Cohort Studies , Ferritins , Humans , Male , SARS-CoV-2 , Systemic Inflammatory Response Syndrome
13.
BMC Public Health ; 22(1): 1961, 2022 10 25.
Article in English | MEDLINE | ID: covidwho-2089185

ABSTRACT

BACKGROUND: Asymptomatic SARS-CoV-2 infection occurring in RT-PCR negative individuals represent a poorly characterized cohort with important infection control connotations. While household and community-based studies have evaluated seroprevalence of antibody and transmission dynamics in this group, workplace-based data is currently unavailable. METHODS: A cohort study was carried out in July 2021, during and immediately following the peak of the 3rd wave of COVID-19 in Sri Lanka, prior to mass vaccination. A total of 92 unvaccinated individuals between the ages of 17-65 years were purposively sampled from an office and two factory settings. The selected cohort that had been exposed to RT-PCR positive cases in the workplace was tested RT-PCR negative. Serological samples collected six weeks post exposure were tested for anti-SARS-CoV-2 neutralizing antibody. RESULTS: The seroprevalence for SARS-CoV-2 specific neutralizing antibodies in the overall cohort was 63.04% (58/92). Seroprevalences in the office setting, factory setting 1 and factory setting 2 were 69.2% (9/13), 55.7% (34/61) and 83.33% (15/18), respectively. Primary risk factor associated with seropositivity was face to face contact with no mask for > 15 min (p < 0.024, Odds Ratio (OR); 5.58, 95%CI;1.292- 25.65). Individuals with workspace exposure had significantly higher levels of neutralizing antibodies than those who did not (percentage neutralization in assay 63.3% (SD:21)vs 45.7% (SD:20), p = 0.0042), as did individuals who engaged socially without protective measures (62.4 (SD:21.6)% vs 49.7 (SD:21)%, p = 0.026). CONCLUSION: There was a high seroprevalence for SARS-CoV-2 specific neutralizing antibodies among RT-PCR negative contacts in workplace settings in Sri Lanka. Higher levels of transmission of SARS-CoV-2 infection than estimated based on RT-PCR positive contact data indicate need for targeted infection control measures in these settings during future outbreaks.


Subject(s)
COVID-19 , Humans , Adolescent , Young Adult , Adult , Middle Aged , Aged , Reverse Transcriptase Polymerase Chain Reaction , COVID-19/epidemiology , COVID-19/prevention & control , Seroepidemiologic Studies , Workplace , Cohort Studies , SARS-CoV-2/genetics , Antibodies, Neutralizing , Vaccination , Antibodies, Viral
14.
BMJ ; 379: e071594, 2022 10 26.
Article in English | MEDLINE | ID: covidwho-2088782

ABSTRACT

OBJECTIVE: To quantify the comparative risk of thrombosis with thrombocytopenia syndrome or thromboembolic events associated with use of adenovirus based covid-19 vaccines versus mRNA based covid-19 vaccines. DESIGN: International network cohort study. SETTING: Routinely collected health data from contributing datasets in France, Germany, the Netherlands, Spain, the UK, and the US. PARTICIPANTS: Adults (age ≥18 years) registered at any contributing database and who received at least one dose of a covid-19 vaccine (ChAdOx1-S (Oxford-AstraZeneca), BNT162b2 (Pfizer-BioNTech), mRNA-1273 (Moderna), or Ad26.COV2.S (Janssen/Johnson & Johnson)), from December 2020 to mid-2021. MAIN OUTCOME MEASURES: Thrombosis with thrombocytopenia syndrome or venous or arterial thromboembolic events within the 28 days after covid-19 vaccination. Incidence rate ratios were estimated after propensity scores matching and were calibrated using negative control outcomes. Estimates specific to the database were pooled by use of random effects meta-analyses. RESULTS: Overall, 1 332 719 of 3 829 822 first dose ChAdOx1-S recipients were matched to 2 124 339 of 2 149 679 BNT162b2 recipients from Germany and the UK. Additionally, 762 517 of 772 678 people receiving Ad26.COV2.S were matched to 2 851 976 of 7 606 693 receiving BNT162b2 in Germany, Spain, and the US. All 628 164 Ad26.COV2.S recipients from the US were matched to 2 230 157 of 3 923 371 mRNA-1273 recipients. A total of 862 thrombocytopenia events were observed in the matched first dose ChAdOx1-S recipients from Germany and the UK, and 520 events after a first dose of BNT162b2. Comparing ChAdOx1-S with a first dose of BNT162b2 revealed an increased risk of thrombocytopenia (pooled calibrated incidence rate ratio 1.33 (95% confidence interval 1.18 to 1.50) and calibrated incidence rate difference of 1.18 (0.57 to 1.8) per 1000 person years). Additionally, a pooled calibrated incidence rate ratio of 2.26 (0.93 to 5.52) for venous thrombosis with thrombocytopenia syndrome was seen with Ad26.COV2.S compared with BNT162b2. CONCLUSIONS: In this multinational study, a pooled 30% increased risk of thrombocytopenia after a first dose of the ChAdOx1-S vaccine was observed, as was a trend towards an increased risk of venous thrombosis with thrombocytopenia syndrome after Ad26.COV2.S compared with BNT162b2. Although rare, the observed risks after adenovirus based vaccines should be considered when planning further immunisation campaigns and future vaccine development.


Subject(s)
COVID-19 Vaccines , Thrombocytopenia , Thromboembolism , Thrombosis , Adolescent , Adult , Humans , Ad26COVS1/adverse effects , BNT162 Vaccine/adverse effects , Cohort Studies , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Thrombocytopenia/epidemiology , Thromboembolism/epidemiology , Thrombosis/epidemiology , Venous Thrombosis/epidemiology
15.
Can J Anaesth ; 69(11): 1399-1404, 2022 11.
Article in English | MEDLINE | ID: covidwho-2085600

ABSTRACT

PURPOSE: SARS-CoV-2 vaccines have been proven effective at preventing poor outcomes from COVID-19; however, voluntary vaccination rates have been suboptimal. We assessed the potential avoidable intensive care unit (ICU) resource use and associated costs had unvaccinated or partially vaccinated patients hospitalized with COVID-19 been fully vaccinated. METHODS: We conducted a retrospective, population-based cohort study of persons aged 12 yr or greater in Alberta (2021 population ~ 4.4 million) admitted to any ICU with COVID-19 from 6 September 2021 to 4 January 2022. We used publicly available aggregate data on COVID-19 infections, vaccination status, and health services use. Intensive care unit admissions, bed-days, lengths of stay, and costs were estimated for patients with COVID-19 and stratified by vaccination status. RESULTS: In total, 1,053 patients admitted to the ICU with COVID-19 were unvaccinated, 42 were partially vaccinated, and 173 were fully vaccinated (cumulative incidence 230.6, 30.8, and 5.5 patients/100,000 population, respectively). Cumulative incidence rate ratios of ICU admission were 42.2 (95% confidence interval [CI], 39.7 to 44.9) for unvaccinated patients and 5.6 (95% CI, 4.1 to 7.6) for partially vaccinated patients when compared with fully vaccinated patients. During the study period, 1,028 avoidable ICU admissions and 13,015 bed-days were recorded for unvaccinated patients and the total avoidable costs were CAD 61.3 million. The largest opportunity to avoid ICU bed-days and costs was in unvaccinated patients aged 50 to 69 yr. CONCLUSIONS: Unvaccinated patients with COVID-19 had substantially greater rates of ICU admissions, ICU bed-days, and ICU-related costs than vaccinated patients did. This increased resource use would have been potentially avoidable had these unvaccinated patients been vaccinated against SARS-CoV-2.


RéSUMé: OBJECTIF: Les vaccins contre le SRAS-CoV-2 se sont avérés efficaces pour prévenir les devenirs défavorables associés à la COVID-19; toutefois, les taux de vaccination volontaire ont été sous-optimaux. Nous avons évalué l'utilisation potentiellement évitable des ressources des unités de soins intensifs (USI) et les coûts associés si les patients non vaccinés ou partiellement vaccinés qui ont dû être hospitalisés pour la COVID-19 avaient été complètement vaccinés. MéTHODE: Nous avons réalisé une étude de cohorte rétrospective basée sur la population de personnes âgées de 12 ans ou plus en Alberta (population de 2021 ~ 4,4 millions) admises dans une unité de soins intensifs et atteintes de COVID-19 du 6 septembre 2021 au 4 janvier 2022. Nous avons utilisé des données agrégées accessibles au public sur les infections à la COVID-19, le statut vaccinal et l'utilisation des services de santé. Les admissions aux soins intensifs, les journées-patients, les durées de séjour et les coûts ont été estimés pour les patients atteints de la COVID-19 et stratifiés selon le statut vaccinal. RéSULTATS: Au total, 1053 patients admis à l'USI souffrant de la COVID-19 n'étaient pas vaccinés, 42 étaient partiellement vaccinés et 173 étaient complètement vaccinés (incidence cumulative 230,6, 30,8 et 5,5 patients / 100 000 habitants, respectivement). Les taux d'incidence cumulés des admissions aux soins intensifs étaient de 42,2 (intervalle de confiance [IC] à 95 %, 39,7 à 44,9) pour les patients non vaccinés et de 5,6 (IC 95 %, 4,1 à 7,6) pour les patients partiellement vaccinés par rapport aux patients entièrement vaccinés. Au cours de la période à l'étude, 1028 admissions évitables aux soins intensifs et 13 015 journées-patients ont été enregistrées pour les patients non vaccinés, et les coûts totaux évitables étaient de 61,3 millions de dollars canadiens. L'économie potentielle la plus importante en matière de journées-patients et de coûts en soins intensifs touchait les patients non vaccinés âgés de 50 à 69 ans. CONCLUSION: Les patients non vaccinés atteints de COVID-19 ont affiché des taux beaucoup plus élevés d'admissions à l'USI, de journées-patients à l'USI et de coûts liés à l'USI que les patients vaccinés. Cette utilisation accrue des ressources aurait été potentiellement évitable si ces patients non vaccinés avaient été vaccinés contre le SRAS-CoV-2.


Subject(s)
COVID-19 , Humans , Cohort Studies , COVID-19/prevention & control , Retrospective Studies , COVID-19 Vaccines , SARS-CoV-2 , Intensive Care Units
17.
JAMA Netw Open ; 5(10): e2238871, 2022 Oct 03.
Article in English | MEDLINE | ID: covidwho-2084948

ABSTRACT

Importance: Data on the association of COVID-19 vaccination with intensive care unit (ICU) admission and outcomes of patients with SARS-CoV-2-related pneumonia are scarce. Objective: To evaluate whether COVID-19 vaccination is associated with preventing ICU admission for COVID-19 pneumonia and to compare baseline characteristics and outcomes of vaccinated and unvaccinated patients admitted to an ICU. Design, Setting, and Participants: This retrospective cohort study on regional data sets reports: (1) daily number of administered vaccines and (2) data of all consecutive patients admitted to an ICU in Lombardy, Italy, from August 1 to December 15, 2021 (Delta variant predominant). Vaccinated patients received either mRNA vaccines (BNT162b2 or mRNA-1273) or adenoviral vector vaccines (ChAdOx1-S or Ad26.COV2). Incident rate ratios (IRRs) were computed from August 1, 2021, to January 31, 2022; ICU and baseline characteristics and outcomes of vaccinated and unvaccinated patients admitted to an ICU were analyzed from August 1 to December 15, 2021. Exposures: COVID-19 vaccination status (no vaccination, mRNA vaccine, adenoviral vector vaccine). Main Outcomes and Measures: The incidence IRR of ICU admission was evaluated, comparing vaccinated people with unvaccinated, adjusted for age and sex. The baseline characteristics at ICU admission of vaccinated and unvaccinated patients were investigated. The association between vaccination status at ICU admission and mortality at ICU and hospital discharge were also studied, adjusting for possible confounders. Results: Among the 10 107 674 inhabitants of Lombardy, Italy, at the time of this study, the median [IQR] age was 48 [28-64] years and 5 154 914 (51.0%) were female. Of the 7 863 417 individuals who were vaccinated (median [IQR] age: 53 [33-68] years; 4 010 343 [51.4%] female), 6 251 417 (79.5%) received an mRNA vaccine, 550 439 (7.0%) received an adenoviral vector vaccine, and 1 061 561 (13.5%) received a mix of vaccines and 4 497 875 (57.2%) were boosted. Compared with unvaccinated people, IRR of individuals who received an mRNA vaccine within 120 days from the last dose was 0.03 (95% CI, 0.03-0.04; P < .001), whereas IRR of individuals who received an adenoviral vector vaccine after 120 days was 0.21 (95% CI, 0.19-0.24; P < .001). There were 553 patients admitted to an ICU for COVID-19 pneumonia during the study period: 139 patients (25.1%) were vaccinated and 414 (74.9%) were unvaccinated. Compared with unvaccinated patients, vaccinated patients were older (median [IQR]: 72 [66-76] vs 60 [51-69] years; P < .001), primarily male individuals (110 patients [79.1%] vs 252 patients [60.9%]; P < .001), with more comorbidities (median [IQR]: 2 [1-3] vs 0 [0-1] comorbidities; P < .001) and had higher ratio of arterial partial pressure of oxygen (Pao2) and fraction of inspiratory oxygen (FiO2) at ICU admission (median [IQR]: 138 [100-180] vs 120 [90-158] mm Hg; P = .007). Factors associated with ICU and hospital mortality were higher age, premorbid heart disease, lower Pao2/FiO2 at ICU admission, and female sex (this factor only for ICU mortality). ICU and hospital mortality were similar between vaccinated and unvaccinated patients. Conclusions and Relevance: In this cohort study, mRNA and adenoviral vector vaccines were associated with significantly lower risk of ICU admission for COVID-19 pneumonia. ICU and hospital mortality were not associated with vaccinated status. These findings suggest a substantial reduction of the risk of developing COVID-19-related severe acute respiratory failure requiring ICU admission among vaccinated people.


Subject(s)
COVID-19 , Pneumonia , Humans , Male , Female , Middle Aged , Adult , COVID-19/epidemiology , COVID-19/prevention & control , SARS-CoV-2 , Critical Illness/therapy , COVID-19 Vaccines , Retrospective Studies , Cohort Studies , BNT162 Vaccine , Intensive Care Units , Pneumonia/epidemiology , Oxygen
18.
JAMA Netw Open ; 5(10): e2238354, 2022 10 03.
Article in English | MEDLINE | ID: covidwho-2084942

ABSTRACT

Importance: The SARS-CoV-2 Omicron subvariant, BA.2, may be less severe than previous variants; however, confounding factors make interpreting the intrinsic severity challenging. Objective: To compare the adjusted risks of mortality, hospitalization, intensive care unit admission, and invasive ventilation between the BA.2 subvariant and the Omicron and Delta variants, after accounting for multiple confounders. Design, Setting, and Participants: This was a retrospective cohort study that applied an entropy balancing approach. Patients in a multicenter inpatient and outpatient system in New England with COVID-19 between March 3, 2020, and June 20, 2022, were identified. Exposures: Cases were assigned as being exposed to the Delta (B.1.617.2) variant, the Omicron (B.1.1.529) variant, or the Omicron BA.2 lineage subvariants. Main Outcomes and Measures: The primary study outcome planned before analysis was risk of 30-day mortality. Secondary outcomes included the risks of hospitalization, invasive ventilation, and intensive care unit admissions. Results: Of 102 315 confirmed COVID-19 cases (mean [SD] age, 44.2 [21.6] years; 63 482 women [62.0%]), 20 770 were labeled as Delta variants, 52 605 were labeled as the Omicron B.1.1.529 variant, and 28 940 were labeled as Omicron BA.2 subvariants. Patient cases were excluded if they occurred outside the prespecified temporal windows associated with the variants or had minimal longitudinal data in the Mass General Brigham system before COVID-19. Mortality rates were 0.7% for Delta (B.1.617.2), 0.4% for Omicron (B.1.1.529), and 0.3% for Omicron (BA.2). The adjusted odds ratio of mortality from the Delta variant compared with the Omicron BA.2 subvariants was 2.07 (95% CI, 1.04-4.10) and that of the original Omicron variant compared with the Omicron BA.2 subvariant was 2.20 (95% CI, 1.56-3.11). For all outcomes, the Omicron BA.2 subvariants were significantly less severe than that of the Omicron and Delta variants. Conclusions and Relevance: In this cohort study, after having accounted for a variety of confounding factors associated with SARS-CoV-2 outcomes, the Omicron BA.2 subvariant was found to be intrinsically less severe than both the Delta and Omicron variants. With respect to these variants, the severity profile of SARS-CoV-2 appears to be diminishing after taking into account various factors including therapeutics, vaccinations, and prior infections.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Female , Adult , COVID-19/epidemiology , Cohort Studies , Retrospective Studies , New England/epidemiology
19.
JAMA ; 328(14): 1415-1426, 2022 10 11.
Article in English | MEDLINE | ID: covidwho-2084927

ABSTRACT

Importance: Data about the association of COVID-19 vaccination and prior SARS-CoV-2 infection with risk of SARS-CoV-2 infection and severe COVID-19 outcomes may guide prevention strategies. Objective: To estimate the time-varying association of primary and booster COVID-19 vaccination and prior SARS-CoV-2 infection with subsequent SARS-CoV-2 infection, hospitalization, and death. Design, Setting, and Participants: Cohort study of 10.6 million residents in North Carolina from March 2, 2020, through June 3, 2022. Exposures: COVID-19 primary vaccine series and boosters and prior SARS-CoV-2 infection. Main Outcomes and Measures: Rate ratio (RR) of SARS-CoV-2 infection and hazard ratio (HR) of COVID-19-related hospitalization and death. Results: The median age among the 10.6 million participants was 39 years; 51.3% were female, 71.5% were White, and 9.9% were Hispanic. As of June 3, 2022, 67% of participants had been vaccinated. There were 2 771 364 SARS-CoV-2 infections, with a hospitalization rate of 6.3% and mortality rate of 1.4%. The adjusted RR of the primary vaccine series compared with being unvaccinated against infection became 0.53 (95% CI, 0.52-0.53) for BNT162b2, 0.52 (95% CI, 0.51-0.53) for mRNA-1273, and 0.51 (95% CI, 0.50-0.53) for Ad26.COV2.S 10 months after the first dose, but the adjusted HR for hospitalization remained at 0.29 (95% CI, 0.24-0.35) for BNT162b2, 0.27 (95% CI, 0.23-0.32) for mRNA-1273, and 0.35 (95% CI, 0.29-0.42) for Ad26.COV2.S and the adjusted HR of death remained at 0.23 (95% CI, 0.17-0.29) for BNT162b2, 0.15 (95% CI, 0.11-0.20) for mRNA-1273, and 0.24 (95% CI, 0.19-0.31) for Ad26.COV2.S. For the BNT162b2 primary series, boosting in December 2021 with BNT162b2 had the adjusted RR relative to primary series of 0.39 (95% CI, 0.38-0.40) and boosting with mRNA-1273 had the adjusted RR of 0.32 (95% CI, 0.30-0.34) against infection after 1 month and boosting with BNT162b2 had the adjusted RR of 0.84 (95% CI, 0.82-0.86) and boosting with mRNA-1273 had the adjusted RR of 0.60 (95% CI, 0.57-0.62) after 3 months. Among all participants, the adjusted RR of Omicron infection compared with no prior infection was estimated at 0.23 (95% CI, 0.22-0.24) against infection, and the adjusted HRs were 0.10 (95% CI, 0.07-0.14) against hospitalization and 0.11 (95% CI, 0.08-0.15) against death after 4 months. Conclusions and Relevance: Receipt of primary COVID-19 vaccine series compared with being unvaccinated, receipt of boosters compared with primary vaccination, and prior infection compared with no prior infection were all significantly associated with lower risk of SARS-CoV-2 infection (including Omicron) and resulting hospitalization and death. The associated protection waned over time, especially against infection.


Subject(s)
COVID-19 , Viral Vaccines , Ad26COVS1 , Adult , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines , Cohort Studies , Female , Humans , Male , SARS-CoV-2 , Vaccination , Viral Vaccines/administration & dosage
20.
Int J Popul Data Sci ; 6(3): 1711, 2021.
Article in English | MEDLINE | ID: covidwho-2081358

ABSTRACT

Introduction: In summer 2021, as rates of COVID-19 decreased and social restrictions were relaxed, live entertainment and sporting events were resumed. In order to inform policy on the safe re-introduction of spectator events, a number of test events were organised in Wales, ranging in setting, size and audience. Objectives: To design and test a method to assess whether test events were associated with an increase in risk of confirmed COVID-19, in order to inform policy. Methods: We designed a cohort study with fixed follow-up time and measured relative risk of confirmed COVID-19 in those attending two large sporting events. First, we linked ticketing information to individual records on the Welsh Demographic Service (WDS), a register of all people living in Wales and registered with a GP, and identified NHS numbers for attendees. Where NHS numbers were not found we used combinations of other identifiers such as email, name, postcode and/or mobile number. We then linked attendees to routine SARS-CoV-2 test data to calculate positivity rates in people attending each event for the period one to fourteen days following the event. We selected a comparison cohort from WDS for each event, individually matched by age band, gender and locality of residence. As many people attended events in family groups we explored the possibility of also matching on household clusters within the comparison group. Risk ratios were then computed for the two events. Results: We successfully assigned NHS numbers to 91% and 84% of people attending the two events respectively. Other identifiers were available for the remainder. Only a small number of attendees (<10) had a record of confirmed COVID-19 following attendance at each event (14 day cumulative incidence: 36 and 26 per 100,000, respectively). There was no evidence of significantly increased risk of COVID-19 at either event. However, the event that didn't include pre-event testing in their mitigations, had a higher risk ratio (3.0 compared to 0.3). Conclusions: We demonstrate the potential for using population data science methods to inform policy. We conclude that, at that point in the epidemic, and with the mitigations that were in place, attending large outdoor sporting events did not significantly increase risk of COVID-19. However, these analyses were carried out between epidemic waves when background incidence and testing rate was low, and need to be repeated during periods of greater transmission. Having a mechanism to identify attendees at events is necessary to calculate risk and feasibility and acceptability of data sharing should be considered.


Subject(s)
COVID-19 , Epidemics , COVID-19/epidemiology , Cohort Studies , Data Science , Humans , SARS-CoV-2
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