Predictive performance and clinical application of COV50, a urinary proteomic biomarker in early COVID-19 infection: a cohort study (preprint)

Background The SARS CoV-2 pandemic remains a worldwide challenge. The CRIT Cov U pilot study generated a urinary proteomic biomarker consisting of 50 peptides (COV50), which predicted death and disease progression. Following the interim analysis demanded by the German government, the full dataset was analysed to consolidate findings and propose clinical applications. Methods In eight European countries, 1012 adults with PCR-confirmed COVID-19 were followed up for death and progression along the 8 point WHO scale. Capillary electrophoresis coupled with mass spectrometry was used for urinary proteomic profiling. Statistical methods included logistic regression, receiver operating curve analysis with comparison of the area under curve (AUC) between nested models. Hospitalisation costs were derived from the care facility corresponding with the Markov chain probability of reaching WHO scores ranging from 3 to 8 and flat-rate hospitalistion costs standardised across countries. Findings The entry WHO scores were 1-3, 4-5 and 6 in 445 (44,0%), 529 (52,3%), and 38 (3,8%) patients, of whom 119 died and 271 progressed. The standardised odds ratios associated with COV50 for death were 2,44 (95% CI, 2,05-2,92) unadjusted and 1,67 (1,34-2,07) if adjusted for sex, age, body mass index, comorbidities and baseline WHO score, and 1,79 (1,60-2,01) and 1,63 (1,40-1,90), respectively, for disease progression (p<0,0001 for all). The predictive accuracy of optimised COV50 thresholds were 74,4% (95% CI, 71,6-77,1) for mortality (threshold 0,47) and 67,4% (64,1-70,3) for disease progression (threshold 0,04). On top of covariables and the baseline WHO score, these thresholds improved AUCs from 0,835 to 0,853 (p=0,0331) and from 0,697 to 0,730 (p=0,0008) for death and progression, respectively. Of 196 ambulatory patients, 194 (99,0%) did not reach the 0,04 threshold. Earlier intervention guided by high-risk COV50 levels should reduce hospital days with cost reductions expressed per 1000 patient-days ranging from MEuro 1,208 (95% percentile interval, 1,035-1,406) at low risk (COV50 <0,04) to MEuro 4,503 (4,107-4,864) at high risk (COV50 above 0,04 and age above 65 years). Interpretation The urinary proteomic COV50 marker is accurate in predicting adverse COVID-19 outcomes. Even in mild-to-moderate PCR-confirmed infections (WHO scores 1-5), the 0,04 threshold justifies earlier drug treatment, thereby reducing hospitalisation days and costs.

COMPARATIVE IMMUNOGENICITY OF BNT162b2 mRNA VACCINE WITH NATURAL COVID-19 INFECTION (preprint)

The mRNA vaccine BNT162b2 has proven highly effective and currently many millions are being vaccinated. There are limited and conflicting data from immunogenicity studies on the effects of age, gender, vaccination side effects (VSE), risk factors for severe COVID-19 (RFS-COV), obesity (BMI) and previous SARS-CoV-2 (Pr-CoV) Moreover, immunogenicity data from COVID-19 patients comparing various disease categories of natural infection i.e. asymptomatic vs mild vs moderate vs severe infection are sparse, and include limited number of individuals. This study included 871 vaccinated health care workers (HCW) and 181 patients with natural infection. Immunogenicity was assessed by a quantative assay measuring anti-SARS-CoV-2 against the RBD domain of the spike protein (anti-RBD) and anti-SARS-CoV-2 against nucleocapsid protein (anti-N). Samples were collected 1-2 weeks after completion of the 2nd dose in the vaccinated HCWs and 15-59 days post symptoms onset in patients with natural infection. The concentration of anti-RBD in vaccinated individuals after multivariable analysis was significantly associated with age, gender, VSE and Pr-CoV. Specifically, anti-RBD median levels (95% CI) were lower by 2,466 (651-5,583), 6,228 (3,254-9,203) and 7,651 (4,479-10,823) AU/ml in 35-44, 45-54, 55-70 yrs respectively, compared with 18-34 yrs group. In females, median levels of anti-RBD were higher by 2,823 (859-4,787) compared with males, in individuals with VSE were higher by 5,024 (3,122-6,926) compared with no VSE, and in HCWs with Pr-CoV were higher by 9,971 (5,158-14,783) AU/ml compared with HCWs without Pr-CoV. Among individuals with natural infection, the median anti-RBD levels were 14.8 times higher in patients with critical COVID-19 infection compared with non-hospitalized individuals. The ratio of anti-RBD in vaccinated individuals versus those with natural infection varied from 1.0 up to 19.4 according to the clinical subgroup of natural infection. This study proves the high immunogenicity of BNT162b2 vaccine although its sustainability remains to be seen. The use of comparative data from natural infection serological panels, expressing the clinical heterogeneity of natural infection may facilitate early decisions for vaccine evaluation in clinical trials.

Antibodies against SARS-CoV-2 among health care workers in a country with low burden of COVID-19 (preprint)

Greece is a country with limited spread of SARS-CoV-2 and cumulative infection attack rate of 0.12% (95%CI 0.06%-0.26%). Health care workers (HCWs) are a well-recognized risk group for COVID-19. The study aimed to estimate the seroprevalence of antibodies to SARS-CoV-2 in two hospitals and assess potential risk factors. Hospital-1 was involved in the care of COVID-19 patients while hospital-2 was not. A validated, rapid, IgM/IgG antibody point-of care test was used. 1,495 individuals consented to participate (response rate 77%). The anti-SARS-CoV-2 weighted prevalence was 1.07% (95%CI 0.37-1.78) overall and 0.44% (95%CI 0.12-1.13) and 2.4% (95%CI 0.51-8.19) in hospital-1 and hospital-2, respectively. The overall, hospital-1, and hospital-2 seroprevalence was 9, 3 and 20 times higher than the estimated infection attack rate in general population, respectively. Suboptimal use of personal protective equipment was noted in both hospitals. These data have implications for the preparedness of a second wave of COVID-19 epidemic.