Publications by authors named "Paula Saa"
Background: Despite data supporting the safety of SARS-CoV-2 vaccination, concerns regarding the receipt of blood products from donors previously infected or vaccinated against SARS-CoV-2 persist. We assessed whether transfusions of plasma or platelet products from donors with prior SARS-CoV-2 infection or vaccination were associated with adverse outcomes in patients without COVID-19.
Methods: We linked donor SARS-CoV-2 spike and nucleocapsid antibody data and vaccination history to blood products transfused between June 1, 2020 and March 31, 2022.
Background: US blood donors are tested for syphilis because the bacterial agent is transfusion transmissible. Here we describe trends over an 11-year period of donations positive for recent and past syphilis infections, and donations classified as syphilis false positive (FP).
Methods: Data from January 1, 2013, to December 31, 2023 (11 years) were compiled for all American Red Cross blood donations to evaluate demographics/characteristics and longitudinal trends in donors testing syphilis reactive/positive.
Spike and nucleocapsid antibody dynamics following SARS-CoV-2 infection and vaccination: Implications for sourcing COVID-19 convalescent plasma from routinely collected blood donations.
Transfusion
November 2024
Article Synopsis
- - COVID-19 convalescent plasma (CCP) may be beneficial for immunocompromised patients, but the FDA's current threshold for qualifying plasma based on antibody levels might be too low.
- - A study evaluated antibody levels in blood donors with different infection and vaccination histories, revealing that those with hybrid immunity (infection followed by vaccination) had higher antibody levels and better neutralizing capabilities.
- - The research suggests establishing new test-based criteria for qualifying CCP, highlighting that plasma with high antibody levels could effectively neutralize various COVID-19 variants for several months after infection or vaccination.
Article Synopsis
- Hepatitis B core antibody (anti-HBc) screening is used in blood establishments worldwide to help prevent the transmission of hepatitis B virus (HBV), especially from donors with occult HBV infection (OBI).
- A survey conducted revealed varied practices in HBV screening across 30 responses from 25 countries, with some establishments screening all donations for anti-HBc and HBV DNA, while others had different approaches, leading to inconsistencies in donor deferral strategies.
- The findings highlight the need for improved confirmation of anti-HBc results to minimize unnecessary donor deferrals while balancing the risk of transmission from anti-HBc negative OBI donors, particularly in high-endemic regions where sensitive HBV DNA testing is crucial.
Article Synopsis
- * They detected a small number (0.2%) of blood samples with antibodies indicating past exposure to the virus, suggesting that SARS-CoV-2 was circulating in the U.S. before the first officially recognized case on January 19, 2020.
- * The findings imply that the early presence of the virus may have gone unnoticed, highlighting the need for more extensive testing and monitoring prior to the outbreak becoming widely recognized.
Article Synopsis
- * A study involving 142,599 blood donors established a new, lower threshold for detecting past infections using the Ortho VITROS Anti-SARS-CoV-2 Total-N Antibody assay, which boosted detection sensitivity while keeping specificity above 98%.
- * The updated test showed a high sensitivity of 98.1% for unvaccinated individuals and 95.6% for those who were vaccinated, though sensitivity was influenced by factors like the virus variant, donor age,
Serial blood and mucosal samples were characterized for 102 participants enrolled a median of 7.0 days after coronavirus disease 2019 diagnosis. Mucosal RNA was detectable for a median of 31.
View Article and Find Full Text PDFChanges in testing behaviors and reporting requirements have hampered the ability to estimate the U.S. SARS-CoV-2 incidence (1).
View Article and Find Full Text PDFArticle Synopsis
- A study tested plasma samples from 1596 donors who reported COVID-19 symptoms after donating blood for SARS-CoV-2 RNA and specific antibodies.* -
- Results showed that having prior infection or vaccination provided protection against developing SARS-CoV-2 RNAemia and symptomatic infection.* -
- The rates of RNAemia remained consistent regardless of whether the samples were taken during the Delta or Omicron variant phases.*
Background: Blood donors were tested for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); resulting antibody levels were monitored over time.
Methods: Donors reactive to anti-SARS-CoV-2 spike protein (S1-total antibodies) participated in a follow-up study of 18 months. Testing for nucleocapsid antibodies distinguished between vaccination and infection.
Article Synopsis
- * A study tested 2,250 blood donors who had possible COVID-19 symptoms after donation, finding that the presence of SARS-CoV-2 RNA peaked at 9%-15% in late 2020, dropping to about 4% after vaccinations were released.
- * Although RNA was detectable in some donors, no infectious virus was found in their plasma, indicating that blood transfusions are very unlikely to transmit SARS-CoV-2.
Background: Previous severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) vaccination, independently and combined ("hybrid immunity"), result in partial protection from subsequent infection and strong protection from severe disease. Proportions of the US population who have been infected, vaccinated, or have hybrid immunity remain unclear, posing a challenge for assessing effective pandemic mitigation strategies.
Methods: In this serial cross-sectional study, nationwide blood donor specimens collected during January-December 2021 were tested for anti-spike and anti-nucleocapsid antibodies, and donor COVID-19 vaccination history of ≥1 dose was collected.
Article Synopsis
- A national serosurvey in the U.S., initiated with the CDC, aimed to determine the prevalence of SARS-CoV-2 infections and vaccinations among blood donors.
- The study began in July 2020 and involved testing around 150,000 blood samples monthly, utilizing a collaborative effort among blood collection organizations, labs, and government partners.
- Results were made publicly accessible through the CDC website, and the study adapted its methods as the pandemic progressed, showcasing the importance of blood donation testing and public-private partnerships during health emergencies.
From December 2020 to June 2021, 1654487 blood donors were tested for antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S1 protein, and 1028547 (62.17%) were reactive. A rapid increase in prevalence was due to vaccination.
View Article and Find Full Text PDFArticle Synopsis
- A study aimed to estimate how many people in the US have SARS-CoV-2 antibodies due to past infection or vaccination, revealing that both factors significantly reduce the risk of getting COVID-19 again.
- The research involved over 1.5 million blood samples collected from donors across all US states and territories between July 2020 and May 2021, providing a broad representation of the population.
- The results indicated that seroprevalence estimates were notably higher than reported COVID-19 case rates, suggesting many more people may have been infected than documented.
In the United States, many blood collection organizations initiated programs to test all blood donors for antibodies to SARS-CoV-2, as a measure to increase donations and to assist in the identification of potential donors of COVID-19 convalescent plasma (CCP). As a result, it was possible to investigate the characteristics of healthy blood donors who had previously been infected with SARS-CoV-2. We report the findings from all blood donations collected by the American Red Cross, representing 40% of the national blood supply covering 44 States, in order to characterize the seroepidemiology of SARS-CoV-2 infection among blood donors in the United States, prior to authorized vaccine availability.
View Article and Find Full Text PDFBackground: The Recipient Epidemiology and Donor Evaluation Study-IV-Pediatric (REDS-IV-P) Epidemiology, Surveillance and Preparedness of the Novel SARS-CoV-2 Epidemic (RESPONSE) seroprevalence study conducted monthly cross-sectional testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in blood donors in 6 US metropolitan regions to estimate the extent of SARS-CoV-2 infections over time.
Methods: During March-August 2020, approximately ≥1000 serum specimens were collected monthly from each region and tested for SARS-CoV-2 antibodies using a well-validated algorithm. Regional seroprevalence estimates were weighted based on demographic differences compared with the general population.
Article Synopsis
- The study investigated the prevalence of SARS-CoV-2 RNA in blood donors from six geographic areas in the U.S. during a period of high community transmission.
- Out of nearly 258,000 blood donations tested, only three samples showed reactive results for SARS-CoV-2 RNA, translating to an estimated prevalence of 1.16 cases per 100,000 donations, with detected viral loads being low.
- No signs of infectivity were observed in the positive samples, suggesting that SARS-CoV-2 RNAemia is rare and not a significant risk for blood donation safety, supporting existing guidelines not to require nucleic acid testing for donors.
Background: A single, simplified approach for human immunodeficiency virus (HIV)-1/HIV-2 antibody confirmation/differentiation is needed for the HIV blood donation supplemental algorithm used in the United States. A clinical evaluation of the Geenius assay was performed-the same assay used for HIV diagnostic confirmation/differentiation in the United States since 2014.
Study Design And Methods: Well-characterized unlinked donation samples classified as HIV negative, false positive, or confirmed positive were included in the study: 200 antibody-nonreactive, 200 HIV-1 immunofluorescence assay (IFA) confirmed-positive, and 100 antibody-screen false-positive donations, equally divided between serum and plasma.
Background: Zika virus (ZIKV) spread to Puerto Rico likely originated from southeastern Brazil approximately 8.5 months earlier than blood donation screening for ZIKV was initiated, but the time of ZIKV introduction in the blood donor population remains unknown.
Methods: To better understand when arboviral infections first appeared in the blood donor pool in Puerto Rico, we retrospectively screened for ZIKV RNA (as well as chikungunya [CHIKV] and dengue [DENV] viral RNA) a repository of 1186 linked blood donor and recipient samples collected from February 2015 to May 2016 as an endpoint efficacy measure following the introduction of platelet pathogen reduction (PR).
Minimal information for studies of extracellular vesicles 2018 (MISEV2018): a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines.
J Extracell Vesicles
November 2018
Article Synopsis
- There's been a lot of new research on tiny structures called extracellular vesicles (EVs) that cells release, which help us understand how cells work and what goes wrong in diseases.
- Scientists have had a hard time studying these EVs because they come in different types and can be tough to separate and analyze properly.
- The International Society for Extracellular Vesicles updated their guidelines, called MISEV2018, to help researchers share clear information about how to study EVs and ensure their findings are accurate and reliable.
Article Synopsis
- A study investigated the characteristics of US blood donors with recent (RBI) or occult (OBI) hepatitis B virus (HBV) infections, analyzing data from 34.4 million donations between 2009-2015.
- Findings showed an overall HBV infection rate of 7.95 per 100,000, with RBI and OBI constituting 26% of infected donors; OBI donors were generally older and had lower viral loads than RBI donors.
- The research highlights the need for comprehensive HBV DNA screening in blood donations and emphasizes the importance of referring infected donors for further care and evaluation.
Background: Because of the potential severe clinical consequences of Zika virus (ZIKV) infection, the large numbers of asymptomatic travelers returning from ZIKV-active areas, the detection of ZIKV nucleic acid in blood, and reports of transmission of ZIKV through transfusion, in 2016 the Food and Drug Administration released recommendations for individual-unit nucleic acid testing to minimize the risk of transmission of ZIKV through blood transfusions.
Methods: The American Red Cross implemented investigational screening of donated blood for ZIKV RNA by means of transcription-mediated amplification (TMA). Confirmatory testing of reactive donations involved repeat TMA, TMA testing in exploratory minipools, real-time reverse-transcriptase polymerase chain reaction, IgM serologic testing, and red-cell TMA.