Risk Perception and Protective Behaviors Against covid-19 in Higher Education Students: The Mediating Role of Fea / Percepção de risco e comportamentos de proteção face à covid-19 em estudantes do ensino superior: o papel mediador do medo / Percepción del riesgo y conductas protectoras frente al covid-19 en estudiantes de enseñanza superior: el papel mediador del miedo

O estudo tem como objetivo descrever os comportamentos de proteção adotados por estudantes portugue-ses do ensino superior durante a pandemia e analisar a sua relação com a percepção de risco e o papel mediador do medo face à covid-19. Participaram 335 estu-dantes com idades entre os 18 e os 29 anos (m= 21.42; dp= 2.43). Os participantes preencheram um inquérito sobre os comportamentos de proteção (i.e., preventi-vos e de evitamento), a percepção de risco e o medo face à covid-19. Os resultados demonstraram que os comportamentos preventivos mais utilizados foram a lavagem/desinfecção das mãos ao longo do dia e o uso de máscara na via pública ou espaços exteriores. Os comportamentos de evitamento mais adotados foram o de evitar locais com aglomeração e os convívios presenciais com colegas/amigos. Verificouse uma as-sociação positiva entre os comportamentos de proteção, a percepção de gravidade e o medo face à covid-19. O medo face à covid-19 foi mediador da relação entre a percepção de gravidade e os comportamentos preventivos (c' = .26, ic 95% [.11; .44]) e de evitamento (c' = .28, ic 95% [.12; .50]). Os resultados são discutidos aten-dendo ao papel da percepção de risco e do medo nas respostas comportamentais dos jovens, num contexto de pandemia, sendo apresentadas implicações práticas e sugestões para estudos futuros.

El estudio tiene como objetivo describir las conductas protectoras adoptadas por los estudiantes portugueses de educación superior durante la pandemia, y analizar su relación con la percepción de riesgo y el papel mediador del miedo al covid-19. Participaron en el estudio 335 estudiantes de entre 18 y 29 años (m = 21.42; ds = 2.43). Los participantes completaron una encuesta sobre conductas protectoras (es decir, preventivas y de evitación), percepción de riesgo y miedo al covid-19. Los resultados mostraron que las conductas preventivas más utilizadas fueron el lavado/desinfección de manos a lo largo del día y el uso de mascarilla en la vía pública o al aire libre. Los comportamientos de evitación más adoptados fueron evadir lugares con reuniones e interacciones cara a cara con compañeros/amigos. Hubo una correlación positiva entre las conductas protectoras, la percepción de seriedad y el miedo al covid-19. También se encontró que el miedo al covid-19 medió la relación entre la percepción de severidad y las conductas preventivas (c' = .26, ic 95% [.11; .44]) y de evitación (c' = .28, ic 95% [.12; .50]). Los resultados se discuten considerando el papel de la percepción del riesgo y el miedo en las respuestas conductuales de los jóvenes en un contexto pandémico, así mismo se presentan impli-caciones prácticas y sugerencias para estudios futuros.

The study aims to describe the protective behaviors adopted by Portuguese higher education students in during the and to analyze their relationship with the perception of risk and the mediating role of fear of covid-19. A total of 335 students aged be-tween 18 and 29 participated in the study (m= 21.42; sd = 2.43). Participants completed a survey on protective (i.e., preventive and avoidance) behaviors, risk perception, and fear of covid-19. The results showed that the most used preventive behaviors were hand washing/disinfection throughout the day and using masks in public streets or outdoor spaces. The most adopted avoidance behaviors were avoiding crowded places and face-to-face interactions with colleagues/friends. There was a positive correlation between pro-tective behaviors, the perception of severity, and fear of covid-19. Fear of covid-19 mediated the relation between the perception of severity and both preventive (c' = .26, ic 95% [.11; .44]) and avoidance (c' = .28, ic95% [.12; .50]) behaviors. The results are discussed considering the role of risk perception and fear in the behavioral responses of young people in a pandemic context while presenting practical implications and suggestions for future studies.

Optimism and fear of COVID-19 in higher education students: the mediating role of general anxiety.

Higher education students have faced several changes in their lives due to the COVID-19 pandemic. This study aims to explore the effect of dispositional optimism in students' fear of COVID-19 and to test the mediating role of general anxiety in the relationship between optimism and fear. Using an online survey, data were collected during the second wave of the pandemic in Portugal. The sample included 312 higher education students (76% females) aged 18-25 years old, who completed measures of dispositional optimism, general anxiety and fear of COVID-19. The results showed that higher optimism and lower general anxiety reduce fear of COVID-19. Moreover, the link between optimism and fear is fully mediated by general anxiety, showing that optimism reduces fear of COVID-19 indirectly through the reduction of students' anxiety. The role of optimism, anxiety and fear in higher education students is discussed and topics for further research are presented.

Selection of plasma donors for the production of anti-SARS-CoV-2 immunoglobulin-based therapies: Strategies for quantitative antibody measurements.

Even after two years of the pandemic, a completely effective treatment against SARS-CoV-2 has not yet been established. Considering this fact and the emergence of successive new viral variants, the development of therapies based on natural polyclonal antibodies recovered from convalescent plasma remains relevant. This study presents a comparison between different methods of screening antibodies in samples of 41 individuals previously diagnosed with COVID-19. We found a significant correlation between Abbot Architect anti-SARS-CoV-2 IgG and Abbott Allinity SARS-CoV-2 IgG II Quantitative assay intensity of reactivity and neutralizing antibody (nAb) titers. Thus, we propose an initial antibody screening with IgG anti-N Abbott Architect test, with an index of, for example, > 3.25 or SARS-CoV-2 IgG II Quantitative Abbott Allinity assay > 137.65 AU/mL as good predictors of Nab ≥ 1:80. For the quantitative method, this threshold demonstrated a 100 % sensitivity and 80 % specificity, with 97.3 % accuracy. An interesting observation was the increase in the neutralizing activity of the anti-SARS-CoV-2 antibodies with the longest interval between the end of the symptoms and the collection, demonstrating that the delay in plasma collection does not affect the achievement of adequate nAbs levels. These results demonstrate the possibility of using faster and more widely available commercial serological tests with a good correlation with viral neutralization tests in culture, allowing for optimized large-scale donor selection, which will be of utmost importance for the development of therapies such as hyperimmune immunoglobulin.

Clusters of SARS-CoV-2 Lineage B.1.1.7 Infection after Vaccination with Adenovirus-Vectored and Inactivated Vaccines.

A SARS-CoV-2 B.1.1.7 variant of concern (VOC) has been associated with increased transmissibility, hospitalization, and mortality. This study aimed to explore the factors associated with B.1.1.7 VOC infection in the context of vaccination. On March 2021, we detected SARS-CoV-2 RNA in nasopharyngeal samples from 14 of 22 individuals vaccinated with a single-dose of ChAdOx1 (outbreak A, n = 26), and 22 of 42 of individuals with two doses of the CoronaVac vaccine (outbreak B, n = 52) for breakthrough infection rates for ChAdOx1 of 63.6% and 52.4% for CoronaVac. The outbreaks were caused by two independent clusters of the B.1.1.7 VOC. The serum of PCR-positive symptomatic SARS-CoV-2-infected individuals had ~1.8-3.4-fold more neutralizing capacity against B.1.1.7 compared to the serum of asymptomatic individuals. These data based on exploratory analysis suggest that the B.1.1.7 variant can infect individuals partially immunized with a single dose of an adenovirus-vectored vaccine or fully immunized with two doses of an inactivated vaccine, although the vaccines were able to reduce the risk of severe disease and death caused by this VOC, even in the elderly.

Neutralisation of SARS-CoV-2 lineage P.1 by antibodies elicited through natural SARS-CoV-2 infection or vaccination with an inactivated SARS-CoV-2 vaccine: an immunological study.

BACKGROUND: Mutations accrued by SARS-CoV-2 lineage P.1-first detected in Brazil in early January, 2021-include amino acid changes in the receptor-binding domain of the viral spike protein that also are reported in other variants of concern, including B.1.1.7 and B.1.351. We aimed to investigate whether isolates of wild-type P.1 lineage SARS-CoV-2 can escape from neutralising antibodies generated by a polyclonal immune response. METHODS: We did an immunological study to assess the neutralising effects of antibodies on lineage P.1 and lineage B isolates of SARS-CoV-2, using plasma samples from patients previously infected with or vaccinated against SARS-CoV-2. Two specimens (P.1/28 and P.1/30) containing SARS-CoV-2 lineage P.1 (as confirmed by viral genome sequencing) were obtained from nasopharyngeal and bronchoalveolar lavage samples collected from patients in Manaus, Brazil, and compared against an isolate of SARS-CoV-2 lineage B (SARS.CoV2/SP02.2020) recovered from a patient in Brazil in February, 2020. Isolates were incubated with plasma samples from 21 blood donors who had previously had COVID-19 and from a total of 53 recipients of the chemically inactivated SARS-CoV-2 vaccine CoronaVac: 18 individuals after receipt of a single dose and an additional 20 individuals (38 in total) after receipt of two doses (collected 17-38 days after the most recent dose); and 15 individuals who received two doses during the phase 3 trial of the vaccine (collected 134-230 days after the second dose). Antibody neutralisation of P.1/28, P.1/30, and B isolates by plasma samples were compared in terms of median virus neutralisation titre (VNT50, defined as the reciprocal value of the sample dilution that showed 50% protection against cytopathic effects). FINDINGS: In terms of VNT50, plasma from individuals previously infected with SARS-CoV-2 had an 8·6 times lower neutralising capacity against the P.1 isolates (median VNT50 30 [IQR <20-45] for P.1/28 and 30 [<20-40] for P.1/30) than against the lineage B isolate (260 [160-400]), with a binominal model showing significant reductions in lineage P.1 isolates compared with the lineage B isolate (p≤0·0001). Efficient neutralisation of P.1 isolates was not seen with plasma samples collected from individuals vaccinated with a first dose of CoronaVac 20-23 days earlier (VNT50s below the limit of detection [<20] for most plasma samples), a second dose 17-38 days earlier (median VNT50 24 [IQR <20-25] for P.1/28 and 28 [<20-25] for P.1/30), or a second dose 134-260 days earlier (all VNT50s below limit of detection). Median VNT50s against the lineage B isolate were 20 (IQR 20-30) after a first dose of CoronaVac 20-23 days earlier, 75 (<20-263) after a second dose 17-38 days earlier, and 20 (<20-30) after a second dose 134-260 days earlier. In plasma collected 17-38 days after a second dose of CoronaVac, neutralising capacity against both P.1 isolates was significantly decreased (p=0·0051 for P.1/28 and p=0·0336 for P.1/30) compared with that against the lineage B isolate. All data were corroborated by results obtained through plaque reduction neutralisation tests. INTERPRETATION: SARS-CoV-2 lineage P.1 might escape neutralisation by antibodies generated in response to polyclonal stimulation against previously circulating variants of SARS-CoV-2. Continuous genomic surveillance of SARS-CoV-2 combined with antibody neutralisation assays could help to guide national immunisation programmes. FUNDING: São Paulo Research Foundation, Brazilian Ministry of Science, Technology and Innovation and Funding Authority for Studies, Medical Research Council, National Council for Scientific and Technological Development, National Institutes of Health. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section.

Low SARS-CoV-2 seroprevalence in a cohort of Brazilian sickle cell disease patients: Possible effects of emphasis on social isolation for a population initially considered to be at very high risk.

Despite being initially considered at higher risk for severe COVID-19, sickle cell disease (SCD) patients have mostly presented clinical severity similar to the general population. As their vulnerability to become infected remains uncertain, we assessed the seroreactivity for SARS-CoV-2 to estimate the prevalence of infection and possible phenotypic and socioeconomic determinants for their contagion. Serologic evaluation was performed on 135 patients with an overall prevalence of 11%; positivity was associated with older age and use of public transportation. We speculate that social distancing instructions recommended by our clinic may have contributed to lower levels of infection, but potential protection factors need further investigation.

Rapid clinical recovery of a SARS-CoV-2 infected common variable immunodeficiency patient following the infusion of COVID-19 convalescent plasma.

BACKGROUND: Common variable immunodeficiency is the most prevalent symptomatic primary immunodeficiency in adults. Affected patients fail to mount an appropriate humoral response against community acquired infectious diseases and recent reports have provided data supporting the increased susceptibility of these patients to severe SARS-CoV-2 infections. In this context, the infusion of COVID-19 convalescent plasma could represent an effective therapeutic strategy. CASE PRESENTATION: 25-year old woman diagnosed with common variable immunodeficiency in 2013, developed severe COVID-19 that rapidly progressed to pneumonia presenting with multiple bilateral lung opacities that were both central and peripheral and presented as ground-glass and consolidation types involving all lobes, bilaterally. As blood oxygen saturation decayed and lung abnormalities were not responsive to large spectrum antibiotics and corticosteroids, patient was placed on mechanical ventilation and compassionate-use of approved COVID-19 convalescent donor plasma was introduced. The patient presented a rapid response to the approach and mechanical ventilation could be interrupted 24 h after first dose of COVID-19 convalescent donor plasma. As a whole, the patient received four doses of 200 mL convalescent plasma during a period of 6 days. There was rapid improvement of clinical status, with interruption of supplemental oxygen therapy after 6 days and reduction of lung abnormalities as evidence by sequential computed tomography scans. CONCLUSIONS: This is a single patient report that adds to other few reports on common variable immunodeficiency and agammaglobulinemia, suggesting that COVID-19 convalescent donor plasma could be a valuable therapeutic approach to treat patients affected by dysgammaglobulinemias and presenting severe COVID-19.