Protection of homologous and heterologous boosters after primary schemes of rAd26-rAd5, ChAdOx1 nCoV-19 and BBIBP-CorV during the omicron outbreak in adults of 50 years and older in Argentina: a test-negative case-control study.

Background: After primary vaccination schemes with rAd26-rAd5 (Sputnik V), ChAdOx1 nCoV-19, BBIBP-CorV or heterologous combinations, the effectiveness of homologous or heterologous boosters (Sputnik V, ChAdOx, Pfizer-BioNTech, Moderna) against SARS-CoV-2 infections, hospitalisations and deaths has been scarcely studied. Methods: Test-negative, case-control study, conducted in Argentina during omicron BA.1 predominance, in adults ≥50 years old tested for SARS-CoV-2 who had received two or three doses of COVID-19 vaccines. Outcomes were COVID-associated infections, hospitalisations and deaths after administering mRNA and vectored boosters, < or ≥60 days from the last dose. Findings: Of 422,124 individuals tested for SARS-CoV-2, 221,993 (52.5%) tested positive; 190,884 (45.2%) and 231,260 (54.8%) had received 2-dose and 3-dose vaccination schemes, respectively. The 3-dose scheme reduced infections, hospitalisations and death (OR 0.81 [0.80-0.83]; 0.28 [0.25-0.32] and 0.25 [0.22-0.28] respectively), but protection dropped after 60 days to 1.04 [1.01-1.06]; 0.52 [0.44-0.61] and 0.38 [0.33-0.45]). Compared with 2-dose-schemes, homologous boosters after primary schemes with vectored-vaccines provided lower protection against infections < and ≥60 days (0.94 [0.92-0.97] and 1.05 [1.01-1.09], respectively) but protected against hospitalisations (0.30 [0.26-0.35]) and deaths (0.29 [0.25-0.33]), decreasing after 60 days (0.59 [0.47-0.74] and 0.51 [0.41-0.64], respectively). Heterologous boosters protected against infections (0.70 [0.68-0.71]) but decreased after 60 days (1.01 [0.98-1.04]) and against hospitalisations and deaths (0.26 [0.22-0.31] and 0.22 [0.18-0.25], respectively), which also decreased after 60 days (0.43 [0.35-0.53] and 0.33 [0.26-0.41], respectively). Heterologous boosters protected against infections when applied <60 days (0.70 [0.68-0.71], p < 0.001), against hospitalisations when applied ≥60 days (0.43 [0.35-0.53], p < 0.01), and against deaths < and ≥60 days (0.22 [0.18-0.25], p < 0.01 and 0.33 [0.26-0.41], p < 0.001). Interpretation: During omicron predominance, heterologous boosters such as viral vectored and mRNA vaccines, following Sputnik V, ChAdOx1, Sinopharm or heterologous primary schemes might provide better protection against death; this effect might last longer in individuals aged ≥50 than homologous boosters. Funding: None.

Safety and immunogenicity of a SARS-CoV-2 Gamma variant RBD-based protein adjuvanted vaccine used as booster in healthy adults.

A Gamma Variant RBD-based aluminum hydroxide adjuvanted vaccine called ARVAC CG was selected for a first in human clinical trial. Healthy male and female participants (18-55 years old) with a complete COVID-19-primary vaccine scheme were assigned to receive two intramuscular doses of either a low-dose or a high-dose of ARVAC CG. The primary endpoint was safety. The secondary objective was humoral immunogenicity. Cellular immune responses were studied as an exploratory objective. The trial was prospectively registered in PRIISA.BA (Registration Code 6564) and ANMAT and retrospectively registered in ClinicalTrials.gov (NCT05656508). Samples from participants of a surveillance strategy implemented by the Ministry of Health of the Province of Buenos Aires that were boosted with BNT162b2 were also analyzed to compare with the booster effect of ARVAC CG. ARVAC CG exhibits a satisfactory safety profile, a robust and broad booster response of neutralizing antibodies against the Ancestral strain of SARS-CoV-2 and the Gamma, Delta, Omicron BA.1 and Omicron BA.5 variants of concern and a booster effect on T cell immunity in individuals previously immunized with different COVID-19 vaccine platforms.

Timing of convalescent plasma administration and 28-day mortality in COVID-19 pneumonia.

This is a multicenter cohort study including consecutive, hospitalized patients ≥18 years, with moderate to severe COVID-19, carried out to evaluate the relationship between the timing of convalescent plasma administration and 28-day mortality. Data were prospectively collected between May 14, 2020 and October 31, 2020. Patients were grouped according to the timing of administration of convalescent plasma as <3 days, between 3 and 7 days, and >7 days. The main outcome variable was 28-day mortality. Independent predictors of mortality were identified by logistic regression. Of 4719 patients receiving convalescent plasma, 3036 (64.3%) were in the general ward, 1171 (24.8%) in the intensive care unit (ICU), and 512 (10.8%) in the ICU on mechanical ventilation. Convalescent plasma was administered to 3113 (66%) patients within the first 3 days of hospital admission, to 1380 (29.2%) between 3 and 7 days, and to 226 after 7 days; 28-day mortality was, respectively, 18.1%, 30.4% and 38.9% (p<0.001). In the regression model, convalescent plasma administration within the first 3 days of admission was associated with reduced 28-day mortality, compared with the administration after 7 days (OR 0.40, 95% CI 0.30 to 0.53). Early convalescent plasma administration was associated to a significant decreased mortality in patients in the general ward (OR 0.45, 95% CI 0.29 to 0.69) and in the ICU (OR 0.35, 95% CI 0.19 to 0.64), but not in those requiring mechanical ventilation (OR 0.52, 95% CI 0.27 to 1.01). In conclusion, this study suggests that early administration of convalescent plasma to patients with COVID-19 pneumonia is critical to obtain therapeutic benefit.

Risk factors for COVID-19 mortality: The effect of convalescent plasma administration.

BACKGROUND: Convalescent plasma, widely utilized in viral infections that induce neutralizing antibodies, has been proposed for COVID-19, and preliminary evidence shows that it might have beneficial effect. Our objective was to determine the risk factors for 28-days mortality in patients who received convalescent plasma for COVID-19 compared to those who did not, who were admitted to hospitals in Buenos Aires Province, Argentina, throughout the pandemic. METHODS: This is a multicenter, retrospective cohort study of 2-month duration beginning on June 1, 2020, including unselected, consecutive adult patients with diagnosed COVID-19, admitted to 215 hospitals with pneumonia. Epidemiological and clinical variables were registered in the Provincial Hospital Bed Management System. Convalescent plasma was supplied as part of a centralized, expanded access program. RESULTS: We analyzed 3,529 patients with pneumonia, predominantly male, aged 62±17, with arterial hypertension and diabetes as main comorbidities; 51.4% were admitted to the ward, 27.1% to the Intensive Care Unit (ICU), and 21.7% to the ICU with mechanical ventilation requirement (ICU-MV). 28-day mortality was 34.9%; and was 26.3%, 30.1% and 61.4% for ward, ICU and ICU-MV patients. Convalescent plasma was administered to 868 patients (24.6%); their 28-day mortality was significantly lower (25.5% vs. 38.0%, p<0.001). No major adverse effects occurred. Logistic regression analysis identified age, ICU admission with and without MV requirement, diabetes, and preexistent cardiovascular disease as independent predictors of 28-day mortality, whereas convalescent plasma administration acted as a protective factor. CONCLUSIONS: Our study suggests that the administration of convalescent plasma in COVID-19 pneumonia admitted to the hospital might be associated with improved outcomes.

[Convalescent plasma therapy in COVID-19 patients, in the Province of Buenos Aires]. / Terapia con plasma de convalecientes en pacientes COVID-19 en la Provincia de Buenos Aires.

This is a preliminary, multicenter, retrospective cohort study, including 272 consecutive patients with COVID-19 admitted to hospitals in Buenos Aires Province, between May 15th and July 1st, 2020, included in an expanded access program to convalescent plasma. Our objectives were to analyze mortality and its independent risk factors, and to assess the occurrence of a favorable evolution, defined as hospital discharge, or stay at the ward, or transfer from ICU to ward. Patients were stratified int o 4 subgroups: admission to the ward with pneumonia and/or oxygen requirement (WARD; n = 100); ICU admission (ICU; n = 87); ICU admission with requirement of mechanical ventilation (ICU-MV; n = 56), and ICU-MV plus septic shock (ICU-MV-SS; N = 29). Mortality at 28 days was 26.1% for the entire group, 14.0% for WARD group, 18.4% for ICU, 44.6% for ICU-MV, and 55.2% for ICU-MV-SS. Mean survival time (days) was 25.6 ± 0.6 (WARD); 25.3 ± 0.7 (ICU); 20.8 ± 1.2 (ICU-MV) and 18.2 ± 1.8 (ICU-MV-SS). Independent predictors of mortality were MV, septic shock and weight. A favorable evolution occurred in 81.4% of WARD patients; in 70.9% of ICU; in 39.6% of ICU-MV and in 27.6% of ICU-MV-SS patients. Severity of illness on admission, age, weight and heart rate were independently associated with evolution. No major adverse effects were recorded. The lack of a control group precluded the estimation of efficacy. However, our 26% mortality rate was higher than that of the treatment arm of clinical trials comparing plasma with usual treatment, which might be ascribed to higher proportion of patients with MV and septic shock in our cohort.

Se trata de un estudio multicéntrico de cohorte retrospectivo, observacional, desde 15/5 a 1/7, 2020, en 272 pacientes COVID-19 internados en hospitales de la provincia de Buenos Aires, incluidos en un programa de acceso expandido de plasma de convalecientes de COVID-19. Nuestros objetivos fueron analizar letalidad y sus factores de riesgo independientes, y evaluar la evolución favorable, definida como alta hospitalaria, permanencia en sala (PISO), o alta de la UTI. Los pacientes fueron estratificados en 4 subgrupos: ingreso a PISO (n = 100) con neumonía y/o requerimiento de oxígeno; a UTI (n = 87); a UTI con requerimiento de ventilación mecánica (UTI-VM; n = 56), y a UTI-VM con shock séptico (UTI-VM-SS; n = 29). La letalidad total a los 28 días fue 26.1%, (71/272), para PISO 14.0%; UTI, 18.4%; UTI-VM, 44.6%; y UTI-VM-SS, 55.2%. El tiempo medio de supervivencia (días): 25.6 ± 0.6 (PISO); 25.3 ± 0.7 (UTI); 20.8 ± 1.2 (UTI-VM) y 18.2 ± 1.8 (UTI- VMSS). Los predictores independientes de letalidad fueron VM, shock séptico y peso. Se registró una evolución favorable en 81.4% de los pacientes en PISO; 70.9% en UTI, 39.6% en UTI-VM, y en 27.6% de UTI-VM-SS. La gravedad al ingreso, edad, peso y frecuencia cardíaca fueron predictores independientes de evolución. No se registraron efectos adversos graves. Por falta de un grupo control, no fue posible evaluar la eficacia del plasma de convaleciente. La letalidad (26%) fue mayor que en otros ensayos clínicos con plasma convaleciente; esto podría deberse a mayor proporción de aquellos con VM y shock séptico en nuestra cohorte.

Terapia con plasma de convalecientes en pacientes Covid-19 en la Provincia de Buenos Aires / Convalescent plasma therapy in COVID-19 patients, in the Province of Buenos Aires

Resumen Se trata de un estudio multicéntrico de cohorte retrospectivo, observacional, desde 15/5 a 1/7, 2020, en 272 pacientes COVID-19 internados en hospitales de la provincia de Buenos Aires, incluidos en un programa de acceso expandido de plasma de convalecientes de COVID-19. Nuestros objetivos fueron analizar letalidad y sus factores de riesgo independientes, y evaluar la evolución favorable, definida como alta hospitalaria, permanencia en sala (PISO), o alta de la UTI. Los pacientes fueron estratificados en 4 subgrupos: ingreso a PISO (n = 100) con neumonía y/o requerimiento de oxígeno; a UTI (n = 87); a UTI con requerimiento de ventilación mecánica (UTI-VM; n = 56), y a UTI-VM con shock séptico (UTI-VM-SS; n = 29). La letalidad total a los 28 días fue 26.1%, (71/272), para PISO 14.0%; UTI, 18.4%; UTI-VM, 44.6%; y UTI-VM-SS, 55.2%. El tiempo medio de supervivencia (días): 25.6 ± 0.6 (PISO); 25.3 ± 0.7 (UTI); 20.8 ± 1.2 (UTI-VM) y 18.2 ± 1.8 (UTIVMSS). Los predictores independientes de letalidad fueron VM, shock séptico y peso. Se registró una evolución favorable en 81.4% de los pacientes en PISO; 70.9% en UTI, 39.6% en UTI-VM, y en 27.6% de UTI-VM-SS. La gravedad al ingreso, edad, peso y frecuencia cardíaca fueron predictores independientes de evolución. No se registraron efectos adversos graves. Por falta de un grupo control, no fue posible evaluar la eficacia del plasma de convaleciente. La letalidad (26%) fue mayor que en otros ensayos clínicos con plasma convaleciente; esto podría deberse a mayor proporción de aquellos con VM y shock séptico en nuestra cohorte.

Abstract This is a preliminary, multicenter, retrospective cohort study, including 272 consecutive patients with COVID-19 admitted to hospitals in Buenos Aires Province, between May 15th and July 1st, 2020, included in an expanded access program to convalescent plasma. Our objectives were to analyze mortality and its independent risk factors, and to assess the occurrence of a favorable evolution, defined as hospital discharge, or stay at the ward, or transfer from ICU to ward. Patients were stratified into 4 subgroups: admission to the ward with pneumonia and/or oxygen requirement (WARD; n = 100); ICU admission (ICU; n = 87); ICU admission with requirement of mechanical ventilation (ICU-MV; n = 56), and ICU-MV plus septic shock (ICU-MV-SS; N = 29). Mortality at 28 days was 26.1% for the entire group, 14.0% for WARD group, 18.4% for ICU, 44.6% for ICU-MV, and 55.2% for ICU-MV-SS. Mean survival time (days) was 25.6±0.6 (WARD); 25.3±0.7 (ICU); 20.8±1.2 (ICU-MV) and 18.2 ± 1.8 (ICU-MV-SS). Independent predictors of mortality were MV, septic shock and weight. A favorable evolution occurred in 81.4% of WARD patients; in 70.9% of ICU; in 39.6% of ICU-MV and in 27.6% of ICU-MV-SS patients. Severity of illness on admission, age, weight and heart rate were independently associated with evolution. No major adverse effects were recorded. The lack of a control group precluded the estimation of efficacy. However, our 26% mortality rate was higher than that of the treatment arm of clinical trials comparing plasma with usual treatment, which might be ascribed to higher proportion of patients with MV and septic shock in our cohort.