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BMJ Open ; 12(1): e049506, 2022 01 17.
Article in English | MEDLINE | ID: covidwho-1629401


OBJECTIVES: Existing UK prognostic models for patients admitted to the hospital with COVID-19 are limited by reliance on comorbidities, which are under-recorded in secondary care, and lack of imaging data among the candidate predictors. Our aims were to develop and externally validate novel prognostic models for adverse outcomes (death and intensive therapy unit (ITU) admission) in UK secondary care and externally validate the existing 4C score. DESIGN: Candidate predictors included demographic variables, symptoms, physiological measures, imaging and laboratory tests. Final models used logistic regression with stepwise selection. SETTING: Model development was performed in data from University Hospitals Birmingham (UHB). External validation was performed in the CovidCollab dataset. PARTICIPANTS: Patients with COVID-19 admitted to UHB January-August 2020 were included. MAIN OUTCOME MEASURES: Death and ITU admission within 28 days of admission. RESULTS: 1040 patients with COVID-19 were included in the derivation cohort; 288 (28%) died and 183 (18%) were admitted to ITU within 28 days of admission. Area under the receiver operating characteristic curve (AUROC) for mortality was 0.791 (95% CI 0.761 to 0.822) in UHB and 0.767 (95% CI 0.754 to 0.780) in CovidCollab; AUROC for ITU admission was 0.906 (95% CI 0.883 to 0.929) in UHB and 0.811 (95% CI 0.795 to 0.828) in CovidCollab. Models showed good calibration. Addition of comorbidities to candidate predictors did not improve model performance. AUROC for the International Severe Acute Respiratory and Emerging Infection Consortium 4C score in the UHB dataset was 0.753 (95% CI 0.720 to 0.785). CONCLUSIONS: The novel prognostic models showed good discrimination and calibration in derivation and external validation datasets, and performed at least as well as the existing 4C score using only routinely collected patient information. The models can be integrated into electronic medical records systems to calculate each individual patient's probability of death or ITU admission at the time of hospital admission. Implementation of the models and clinical utility should be evaluated.

COVID-19 , Hospital Mortality , Humans , Prognosis , Retrospective Studies , Risk Assessment , SARS-CoV-2 , Secondary Care
Preprint | SSRN | ID: ppcovidwho-297180


Background: Age and frailty are risk factors for poor clinical outcomes following SARS-CoV-2 infection. As such, COVID-19 vaccination has been prioritised for this group but there is concern that immune responses may be impaired due to immune senescence and co-morbidity. Methods: We studied antibody and cellular immune responses following COVID-19 vaccination in 202 staff and 286 residents of long-term care facilities (LTCF). Due to the high prevalence of previous infection within this environment 50% and 51% of these two groups respectively had serological evidence of prior natural SARS-CoV-2 infection. Results: In both staff and residents with previous infection the antibody responses following dual vaccination were strong and equivalent across the age course. In contrast, within infection-naïve donors these responses were reduced by 2.4-fold and 8.1-fold respectively such that values within the resident population were 2.6-fold lower than in staff. Impaired neutralisation of delta variant spike binding was also apparent within donors without prior infection. Spike-specific T cell responses were also markedly enhanced by prior infection and within infection-naive donors were 52% lower within residents compared to staff. Post-vaccine spike-specific CD4+ T cell responses displayed single or dual production of IFN-γ+ and IL-2+ whilst previous infection primed for an extended functional profile with TNF-ɑ+ and CXCL10 production. Interpretation: These data reveal suboptimal post-vaccine immune responses within infection-naïve elderly residents of LTCF and indicate the need for further optimization of immune protection through the use of booster vaccination.

Lancet Healthy Longev ; 2(9): e554-e560, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1433992


Background: In several countries, extended interval COVID-19 vaccination regimens are now used to accelerate population coverage, but the relative immunogenicity of different vaccines in older people remains uncertain. In this study we aimed to assess the antibody and cellular responses of older people after a single dose of either the BNT162b2 vaccine (tozinameran; Pfizer-BioNTech) or ChAdOx1 nCoV-19 vaccine (Oxford University-AstraZeneca). Methods: Participants aged 80 years or older, who did not live in a residential or care home or require assisted living, and had received a single dose of either the BNT162b2 vaccine or ChAdOx1 nCoV-19 vaccine were eligible to participate. Participants were recruited through local primary care networks in the West Midlands, UK. Blood samples and dried blood spots were taken 5-6 weeks after vaccination to assess adaptive immune responses using Elecsys electrochemiluminescence immunoassay and cellular responses by ELISpot. Primary endpoints were percentage response and quantification of adaptive immunity. Findings: Between Dec 29, 2020, and Feb 28, 2021, 165 participants were recruited and included in the analysis. 76 participants had received BNT162b2 (median age 84 years, IQR 82-89; range 80-98) and 89 had received ChAdOx1 nCoV-19 (median age 84 years, 81-87; 80-99). Antibody responses against the spike protein were detectable in 69 (93%) of 74 BNT162b2 vaccine recipients and 77 (87%) of 89 ChAdOx1 nCoV-19 vaccine recipients. Median antibody titres were of 19·3 U/mL (7·4-79·4) in the BNT162b2 vaccine recipients and 19·6 U/mL (6·1-60·0) in the ChAdOx1 nCoV-19 vaccine recipients (p=0·41). Spike protein-specific T-cell responses were observed in nine (12%) of 73 BNT162b2 vaccine recipients and 27 (31%) of 88 ChAdOx1 nCoV-19 vaccine recipients, and median responses were three-times higher in ChAdOx1 nCoV-19 vaccine recipients (24 spots per 1 × 106 peripheral blood mononuclear cells) than BNT162b2 vaccine recipients (eight spots per 1 × 106 peripheral blood mononuclear cells; p<0·0001). Humoral and cellular immune responses against spike protein were correlated in both cohorts. Evidence of previous SARS-CoV-2 infection was seen in eight participants (n=5 BNT162b2 recipients and n=3 ChAdOx1 nCoV-19 recipients), and was associated with 691-times and four-times increase in humoral and cellular immune responses across the whole cohort. Interpretation: Single doses of either BNT162b2 or ChAdOx1 nCoV-19 in older people induces humoral immunity in most participants, and is markedly enhanced by previous infection. Cellular responses were weaker, but showed enhancement after the ChAdOx1 nCoV-19 vaccine at the 5-6 week timepoint. Funding: Medical Research Council, National Institute for Health Research, and National Core Studies.