SARS-CoV-2-specific nasal IgA wanes 9 months after hospitalisation with COVID-19 and is not induced by subsequent vaccination

BACKGROUND: Most studies of immunity to SARS-CoV-2 focus on circulating antibody, giving limited insights into mucosal defences that prevent viral replication and onward transmission. We studied nasal and plasma antibody responses one year after hospitalisation for COVID-19, including a period when SARS-CoV-2 vaccination was introduced. METHODS: In this follow up study, plasma and nasosorption samples were prospectively collected from 446 adults hospitalised for COVID-19 between February 2020 and March 2021 via the ISARIC4C and PHOSP-COVID consortia. IgA and IgG responses to NP and S of ancestral SARS-CoV-2, Delta and Omicron (BA.1) variants were measured by electrochemiluminescence and compared with plasma neutralisation data. FINDINGS: Strong and consistent nasal anti-NP and anti-S IgA responses were demonstrated, which remained elevated for nine months (p < 0.0001). Nasal and plasma anti-S IgG remained elevated for at least 12 months (p < 0.0001) with plasma neutralising titres that were raised against all variants compared to controls (p < 0.0001). Of 323 with complete data, 307 were vaccinated between 6 and 12 months; coinciding with rises in nasal and plasma IgA and IgG anti-S titres for all SARS-CoV-2 variants, although the change in nasal IgA was minimal (1.46-fold change after 10 months, p = 0.011) and the median remained below the positive threshold determined by pre-pandemic controls. Samples 12 months after admission showed no association between nasal IgA and plasma IgG anti-S responses (R = 0.05, p = 0.18), indicating that nasal IgA responses are distinct from those in plasma and minimally boosted by vaccination. INTERPRETATION: The decline in nasal IgA responses 9 months after infection and minimal impact of subsequent vaccination may explain the lack of long-lasting nasal defence against reinfection and the limited effects of vaccination on transmission. These findings highlight the need to develop vaccines that enhance nasal immunity. FUNDING: This study has been supported by ISARIC4C and PHOSP-COVID consortia. ISARIC4C is supported by grants from the National Institute for Health and Care Research and the Medical Research Council. Liverpool Experimental Cancer Medicine Centre provided infrastructure support for this research. The PHOSP-COVD study is jointly funded by UK Research and Innovation and National Institute of Health and Care Research. The funders were not involved in the study design, interpretation of data or the writing of this manuscript

Effect of Tissue Processing on Assessment of Endoscopic Intestinal Biopsies in Dogs and Cats

Background: Prior studies failed to detect significant association between hypoalbuminemia and small intestinal lesions. Hypothesis: Use of pictorial templates will enhance consistency of interpathologist interpretation and identification of intestinal lesions associated with hypoalbuminemia. Animals: Tissues from 62 dogs and 25 cats examined as clinical cases at 7 referral veterinary practices in 4 countries. Methods: Retrospective, observational study. Histopathology slides from sequential cases undergoing endoscopic biopsy were examined by 4 pathologists by pictorial templates. Changes for 9 microscopic features were recorded as normal, mild, moderate or severe, and 2- and 4-point scales were tested for consistency of interpretation. Logistic regression models determined odds ratios (OR) of histologic lesions being associated with hypoalbuminemia while k statistics determined agreement between pathologists on histologic lesions. Results: There was poor agreement (k= -0.013 to 0.3) between pathologists, and institution of origin of slides had effect (k = 1.0 for 3 of 4 lesions on slides from Institution 5) on agreement between pathologists on selected histologic features. Using 2 point as opposed to 4-point grading scale increased agreement between pathologists (maximum k = 0.69 using 4-point scale versus maximum k = 1.0 using 2-point scale). Significant association (P = .019\u2013 .04; 95% OR = 3.14\u201310.84) between lacteal dilation and hypoalbuminemia was found by 3 pathologists. Conclusions and Clinical Importance: Substantial inconsistency between pathologists remains despite use of pictorial template because of differences in slide processing. Distinguishing between mild and moderate lesions might be important source of the disagreement among pathologists

Avaliação do feno de Egeria densa na alimentação de carneiros Egeria densa hay inclusion in ration for sheep

Este experimento foi realizado com o objetivo de avaliar o efeito da inclusão de Egeria densa na ração sobre o consumo voluntário, o ganho de peso e a conversão alimentar de ovinos Santa Inês. Dezesseis ovinos foram distribuídos ao acaso em quatro tratamentos: T0 = 81% de feno de tifton (FT) e 19% de concentrado (farelo de soja e milho); T27 = 27% de feno de Egeria (FE), 54% de FT e 19% de concentrado; T54 54% de FE, 27% de FT e 19% de concentrado e T81 = 81% de FE e 19% de concentrado. Verificou-se que o consumo voluntário foi reduzido, e o ganho de peso, quando analisado todo o período experimental, não foi afetado pela adição de feno de Egeria. Durante o período experimental, verificou-se que o ganho de peso foi uniforme nos animais que receberam as dietas sem e com 27% feno de Egeria. Quando as dietas continham 54 e 81% de feno de Egeria, o ganho de peso apresentou comportamento quadrático. Apesar da alta concentração de alguns elementos minerais, a Egeria tem potencial como forrageira para ovinos, desde que seja fornecida em baixa proporção na ração ou por curto período.<br>Sixteen Santa Inês sheep were randomly allotted to four treatments (T0 = 81% tifton hay (TH) and 19% concentrate (soybean meal and corn); T27 = 27% egeria hay (EH), 54% TH and 19% concentrate; T81 = 81% EH and 19% concentrate) to evaluate the effect of Egeria hay inclusion in the diet on voluntary intake, weight gain and feed efficiency. Voluntary intake reduced and body weight gain was not affected by EH inclusion. During the experimental period, weight gain was similar for the animals fed diet without or with 27% EH. EH inclusion (at levels of 54 and 81%) affected quadractricaly body weight gain. Despite of the high minerals concentration, EH could be used as forage in small quantity or for short period