Positive SARS‐CoV‐2 RT‐qPCR of a nasal swab spot after 30 days of conservation on filter paper at room temperature

alexandrossfakianakis shared this article with you from Inoreader Positive SARS‐CoV‐2 RT‐qPCR of a nasal swab spot after 30 days of conservation on filter paper at room temperature via Journal of Medical Virology Abstract We tested the use of nasal swabs spotted onto filter paper (Whatman 3M, Germany) for the molecular diagnosis of SARS-CoV-2 infection. Spots of a positive nasal swab in conservation medium (B.1.177 strain, 21Ct) were still positive (duo E-gene/IP4) after 10, 20, and 30 days of conservation at room temperature, with Ct values of 28, 27, and 26, respectively. Direct spotting of the swab at bedside (omicron strain) still gave a positive result after 10 days in two RT-qPCR systems: 33.7 Ct using duo E-gene/IP4, and 34.8 using a specific Omicron system. Spotting of a dilution range of media spiked with the Delta (strain 2021/FR/0610, lineage B 1.617.2) and Omicron strains (strain UVE/SARS-CoV-2/2021/FR/1514) showed a threshold of 0.04 TCID50 after 10 days of conservation. We show, for the first time, that this simple and low-cost conservation method can be used to store samples for RT-qPCR against SARS-CoV-2 for up to at least one month. This article is prot ected by copyright. All rights reserved. View on Web

Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

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

Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.

Perspectives from recent advances of Helicobacter pylori vaccines research

alexandrossfakianakis shared this article with you from Inoreader Perspectives from recent advances of Helicobacter pylori vaccines research via Helicobacter Abstract Background Helicobacter pylori (H. pylori) infection is the main factor leading to some gastric diseases. Currently, H. pylori infection is primarily treated with antibiotics. However, with the widespread application of antibiotics, H. pylori resistance to antibiotics has also gradually increased year by year. Vaccines may be an alternative solution to clear H. pylori. Aims By reviewing the recent progress on H. pylori vaccines, we expected it to lead to more research efforts to accelerate breakthroughs in this field. Materials & Methods We searched the research on H. pylori vaccine in recent years through PubMed®, and then classified and summarized these studies. Results The study of the pathogenic mechanism of H. pylori has led to the development of vaccines using some antigens, such as urease, catalase, and heat shock protein (Hsp). Based on these antigens, whole-cell, subunit, nucleic acid, vector, and H. pylori exosome vaccines have been tested. Discussion At present, researchers have developed many types of vaccines, such as whole cell vaccines, subunit vaccines, vector vaccines, etc. However, although some of these vaccines induced protective immunity in mouse models, only a few were able to move into human trials. We propose that mRNA vaccine may play an important role in preventing or treating H. pylori infection. The current study shows that we have developed various types of vaccines based on the virulence factors of H. pylori. However, only a few vaccines have entered human clinical trials. In order to improve the efficacy of vaccines, it is necessary to enhance T-cell immunity. Conclusion We should fully understand the pathogenic mechanism of H. pylori and find its core antigen as a vaccine target. View on Web

Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.