Differential neutralization and inhibition of SARS-CoV-2 variants by antibodies elicited by COVID-19 mRNA vaccines

IntroductoryThe evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in the emergence of many new variant lineages that have exacerbated the COVID-19 pandemic. Some of those variants were designated as variants of concern/interest (VOC/VOI) by national or international authorities based on many factors including their potential impact on vaccines. To ascertain and rank the risk of VOCs and VOIs, we analyzed their ability to escape from vaccine-induced antibodies. The variants showed differential reductions in neutralization and replication titers by post-vaccination sera. Although the Omicron variant showed the most escape from neutralization, sera collected after a third dose of vaccine (booster sera) retained moderate neutralizing activity against that variant. Therefore, vaccination remains the most effective strategy to combat the COVID-19 pandemic.

SARS-CoV-2 spike D614G variant confers enhanced replication and transmissibility

During the evolution of SARS-CoV-2 in humans a D614G substitution in the spike (S) protein emerged and became the predominant circulating variant (S-614G) of the COVID-19 pandemic1. However, whether the increasing prevalence of the S-614G variant represents a fitness advantage that improves replication and/or transmission in humans or is merely due to founder effects remains elusive. Here, we generated isogenic SARS-CoV-2 variants and demonstrate that the S-614G variant has (i) enhanced binding to human ACE2, (ii) increased replication in primary human bronchial and nasal airway epithelial cultures as well as in a novel human ACE2 knock-in mouse model, and (iii) markedly increased replication and transmissibility in hamster and ferret models of SARS-CoV-2 infection. Collectively, our data show that while the S-614G substitution results in subtle increases in binding and replication in vitro, it provides a real competitive advantage in vivo, particularly during the transmission bottle neck, providing an explanation for the global predominance of S-614G variant among the SARS-CoV-2 viruses currently circulating.

Practice on the data normalization of medical device adverse event reporting and exploration on improving the quality of the reports / 中国医疗器械杂志

On the basis of real working practices in data normalization, the case reports from the monitoring system were studied, non-standard reports were summarized and the reasons were analyzed, the methods of data normalization and improving the reporting quality were discussed. The standard databases and the rule databases were created, they were capable of automatic completion of the standardization work of new cases.

Clinical study on treatment of HIV infected persons based on viral load detection and CD4+ T lymphocyte counting / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the usage of viral load and CD4+ cell count methods in evaluating the effects of clinical treatment in HIV infected people.</p><p><b>METHODS</b>Totally 73 cases of HIV infected persons were studied with clinical observation and laboratory examinations, six cases were treated with cocktail therapy, 36 cases with chinese herbs and the other 31 cases were untreated.</p><p><b>RESULTS</b>The results indicated that the viral load levels in cocktail therapy group were significantly lower than the other two groups within 3 months and then kept at very low level. The CD4+ T lymphocyte levels showed a significant increase after 3 months and kept rising up. The chinese herb group, however, had no significant difference in viral load level and CD4+ T lymphocyte level as compared with untreated group. But in clinical observation chinese herbs showed the effect of improving clinical status in some cases.</p><p><b>CONCLUSIONS</b>The authors conclude that the viral load and CD4+ count are efficient methods in clinical evaluation of HIV treatment, especially in routine anti-HIV therapy. As for the chinese herbs treatment, these two monitors did not reflect changes in clinical status.</p>

Serologic evidence of quality improvement of domestic HIV-antibody detecting ELISA kits / 中国输血杂志

Objective To investigate the quality of current domestic HIV antibody detecting kits and to assure the credibility of experimental results.Methods The sensitivity and specificity of three kinds of domestic HIV antibody detection ELISA kits made in three different years were evaluated and compared by testing the serum panel from National AIDS Reference Laboratory.Results The sensitivity of kits produced by three domestic manufacturers in 2001 is significantly better than the kits produced in 1998 and 1999.The false negative rates were apparently decreasing.Conclusions The quality of domestic HIV antibody detecting kits has been improving steadily.The sensitivity of double antigen sandwich ELISA assay is apparently better than the indirect ELISA assay.