ABSTRACT Exacerbated inflammation and coagulation are a hallmark of COVID-19 severity. Extracellular vesicles (EVs) are intercellular transmitters involved in inflammatory conditions, which are capable of triggering prothrombotic mechanisms. Since the release of EVs is potentially associated with COVID-19-induced coagulopathy, the aim of this study was to evaluate changes in inflammation- and hypercoagulability-related EVs during the first month after symptom onset and to determine whether they are associated with disease severity. Blood samples of patients with mild or severe forms of the disease were collected on three occasions: in the second, third and fourth weeks after symptom onset for the quantification by flow cytometry of CD41A (platelet glycoprotein IIb/IIIa), CD162 (PSGL-1), CD31 (PECAM-1) and CD142 cells (tissue factor). Analysis of variance (ANOVA) with repeated measures, Kruskal-Wallis and correlation tests were used. Eighty-five patients were enrolled, 71% of whom had mild disease. Seventeen uninfected individuals served as controls. Compared to controls, both mild and severe COVID-19 were associated with higher EV-CD31+, EV-CD41+ and EV-CD142+ levels. All EV levels were higher in severe than in mild COVID-19 only after the third week from symptom onset, as opposed to C-reactive protein and D-dimer levels, which were higher in severe than in mild COVID-19 earlier during disease progression. EV levels were also associated with C-reactive protein and D-dimer levels only after the third week of symptoms. In conclusion, EVs expressing CD41A, CD31, TF, and CD162 appear as late markers of COVID-19 severity. This finding may contribute to the understanding of the pathogenesis of acute and possibly long COVID-19. COVID19 COVID 19 COVID-1 severity (EVs conditions mechanisms COVID19induced COVIDinduced induced coagulopathy hypercoagulabilityrelated hypercoagulability related occasions second CDA CD A platelet IIb/IIIa, IIbIIIa IIb/IIIa , IIb IIIa IIb/IIIa) CD16 PSGL1, PSGL1 PSGL 1 (PSGL-1) CD3 PECAM1 PECAM (PECAM-1 CD14 tissue factor. factor . factor) ANOVA (ANOVA measures KruskalWallis Kruskal Wallis used Eightyfive Eighty five enrolled 71 controls EVCD31+, EVCD31 EVCD CD31+, EV-CD31+ EVCD41+ EVCD41 CD41+ CD41 EV-CD41 EVCD142+ EVCD142 CD142+ EV-CD142 Creactive C reactive Ddimer D dimer progression symptoms conclusion TF COVID19. 19. COVID1 COVID- CD1 (PSGL-1 (PECAM- 7 EVCD31+ EVCD3 CD31+ EV-CD31 EVCD4 CD4 EV-CD4 EVCD14 EV-CD14 (PSGL- (PECAM EV-CD3 EV-CD EVCD1 EV-CD1 (PSGL

ABSTRACT The measles, mumps and rubella (MMR) vaccine is usually recommended from 24 months after a hematopoietic stem cell transplant (HSCT). Some authors have demonstrated that the MMR vaccination can be safe from 12 months post-HSCT in non-immunosuppressed patients, as recommended by the Brazilian National Immunization Program/Ministry of Health, since 2006. The objectives of this study were to evaluate when patients received MMR vaccine after an HSCT in our care service and if there were reports of any side effects. We retrospectively reviewed the records of HSCT recipients who received at least one MMR dose in our care service, a quaternary teaching hospital in Sao Paulo city, Brazil, from 2017 to 2021. We identified 82 patients: 75.6% (90.1% in the autologous group and 45.1% in the allogeneic group) were vaccinated before 23 months post-transplantation. None reported side effects following the vaccination. Our data support that the MMR vaccination is safe from 12 to 23 months after HSCT. measles (MMR 2 . (HSCT) 1 postHSCT post nonimmunosuppressed non immunosuppressed ProgramMinistry Program Ministry Health 2006 city Brazil 201 2021 8 756 75 6 75.6 90.1% 901 90 (90.1 451 45 45.1 posttransplantation. posttransplantation transplantation. transplantation post-transplantation (HSCT 200 20 202 7 75. 90.1 9 (90. 4 45. 90. (90 (9 (

Abstract By decreasing the pre-seroconversion window period, nucleic acid testing (NAT) has improved the safety of blood products and reduced the risk of transfusion-transmitted infections. Between 2011 and 2017, NAT determinations for approximately 898,202 donations were performed at Fundação Pró-Sangue/Hemocentro de São Paulo (FPS-HSP). Three seronegative HIV-viremic donations were detected. The NAT yield rate per million donations was 3.34 for HIV, and the acute HIV-1 infections detected are described, followed by a brief review of the situation in Brazil.