Vaccine‐induced binding and neutralizing antibodies against Omicron 6 months after a homologous BNT162b2 booster

alexandrossfakianakis shared this article with you from Inoreader Vaccine‐induced binding and neutralizing antibodies against Omicron 6 months after a homologous BNT162b2 booster via Journal of Medical Virology Abstract Introduction Evidence about the long-term persistence of the booster-mediated immunity against Omicron is mandatory for pandemic management and deployment of vaccination strategies. Methods A total of 155 healthcare professionals (104 COVID-19 naive and 51 with a history of SARS-COV-2 infection) received a homologous BNT162b2 booster. Binding antibodies against the spike protein and neutralizing antibodies against Omicron were measured at several time points before and up to 6 months after the booster. Geometric mean titers of measured antibodies were correlated to vaccine efficacy against symptomatic disease. Results Compared to the highest response, a significant 10.2 and 11.5-fold decrease in neutralizing titers was observed after 6 months in participants with and without history of SARS-CoV-2 infection. A corresponding 2.5 and 2.9-fold decrease in binding antibodies was observed. The estimated T1/2 of neutralizing antibodies in pa rticipants with and without history of SARS-CoV-2 infection was 42 (95%CI, 25–137) and 36 days (95%CI, 25–65). Estimated T1/2 were longer for binding antibodies: 168 (95%CI, 116–303) and 139 days (95%CI, 113–180), respectively. Both binding and neutralizing antibodies were strongly correlated to vaccine efficacy (r = 0.83 and 0.89). However, binding and neutralizing antibodies were modestly correlated, and a high proportion of subjects (36.7%) with high binding antibody titers (i.e. > 8,434 BAU/mL) did not have neutralizing activity. Conclusion A considerable decay of the humoral response was observed 6 months after the booster, and was strongly correlated with vaccine efficacy. Our study also shows that commercial assays available in clinical laboratories might require adaptation to better predict neutralization in the Omicron era. This article is protected by copyright. All rights reserved. View on Web

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Longitudinal Effects of Base of Tongue Concurrent Chemoradiation Therapy in a Pre‐Clinical Model

alexandrossfakianakis shared this article with you from Inoreader Longitudinal Effects of Base of Tongue Concurrent Chemoradiation Therapy in a Pre‐Clinical Model via The Laryngoscope We present a clinically relevant animal model quantifying the effects of concurrent chemoradiation therapy (CCRT) on tongue strength and elasticity over time. This study demonstrates an increasing difference in tongue strength over time between control animals and those exposed to CCRT. Tongue elasticity was not significantly affected by CCRT, suggesting that changes in strength may not be caused by fibrosis during the time period studied. Background/Objectives Base of tongue (BOT) dysfunction is common following oropharyngeal concurrent chemoradiation therapy (CCRT). We present a clinically relevant animal model quantifying the effects of CCRT on tongue strength and elasticity over time. Methods Fifty-three male and 53 female Sprague–Dawley rats were randomized to control or experimental groups. Experimental animals received cisplatin, 5-fluorouracil, and 5 fractions of 7 Gy directed to the BOT. Controls received no intervention. At 2 weeks, 5 months, or 10 months after CCRT, animals underwent non-survival surgery to measure twitch and tetanic tongue strength, which were analyzed using multivariate linear mixed effects models. Tongue displacement, a surrogate for tongue elasticity, was also determined via stress–strain testing and analyzed via a multivariate linear mixed effects model. Results Reporting the combined results of both sexes, the estimated experimental group mean peak twitch forces became more divergent over time compared to controls, being 8.3% lower than controls at 2 weeks post-CCRT, 15.7% lower at 5 months, and 31.6% lower at 10 months. Estimated experimental group mean peak tetanic forces followed a similar course and were 2.9% lower than controls at 2 weeks post CCRT, 20.7% lower at 5 months, and 27.0% lower at 10 months. Stress–strain testing did not find CCRT to have a significant effect on tongue displacement across experimental timepoints. Conclusions This study demonstrates an increasing difference in tongue strength over time between controls and animals exposed to CCRT. Tongue elasticity was not significantly affected by CCRT, suggesting that changes in strength may not be caused by fibrosis. Level of Evidence NA Laryngoscope, 2022 View on Web

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