Safety of COVID-19 vaccine in patients with myasthenia gravis: a self-controlled case series study.

Background: The safety of COVID-19 vaccines has been clarified in clinical trials; however, some immunocompromised patients, such as myasthenia gravis (MG) patients, are still hesitant to receive vaccines. Whether COVID-19 vaccination increases the risk of disease worsening in these patients remains unknown. This study aims to evaluate the risk of disease exacerbation in COVID-19-vaccinated MG patients. Methods: The data in this study were collected from the MG database at Tangdu Hospital, the Fourth Military Medical University, and the Tertiary Referral Diagnostic Center at Huashan Hospital, Fudan University, from 1 April 2022 to 31 October 2022. A self-controlled case series method was applied, and the incidence rate ratios were calculated in the prespecified risk period using conditional Poisson regression. Results: Inactivated COVID-19 vaccines did not increase the risk of disease exacerbation in MG patients with stable disease status. A few patients experienced transient disease worsening, but the symptoms were mild. It is noted that more attention should be paid to thymoma-related MG, especially within 1 week after COVID-19 vaccination. Conclusion: COVID-19 vaccination has no long-term impact on MG relapse.

Genomic characterization and phylogenetic evolution of the SARS-CoV-2.

 The coronavirus disease 2019 (COVID-19) starting on 12 December 2019 in Wuhan, China, caused 7,885,123 cases including 431,835 deaths by 14 Jun 2020 all over the world. Here we report the genomic characterization and phylogenetic evolution of coronavirus SARS-CoV-2 causing COVID-19. The SARS-CoV-2 and other coronavirus genomes were obtained from GISAID and GenBank. The genomes were annotated and potential genetic recombination was investigated. Phylogenetic analysis was conducted and used to determine the evolutionary history of the virus and to elucidate the origin of the virus. The analysis had revealed that SARS-CoV-2 possessed a similar genomic organization to bat-SARS-like-CoV collected in China. The genome sequences of SARS-CoV-2 were very similar, showing 99.6-100% sequence identity. Notably, SARS-CoV-2 was closely related (with 88% identity) to bat-SARS-like coronavirus, but was more distant from SARS-CoV (about 79%) and MERS-CoV (about 50%). Phylogenetic tree of the complete viral genome showed that the virus clustered with bat SARS-like coronavirus. The results of the similarity between SARS-CoV-2 and related viruses did not identify any potential genomic recombination events. Therefore, it seems that the SARS-CoV-2 might be originally hosted by bats, and might have been transmitted to humans via intermediate hosts of currently unknown wild animal(s). Finally, based on the wide spread of SARS-CoV in their natural reservoirs, future studies should focus more on surveillance of coronaviruses, and measures against the domestication and consumption of wild animals should be implemented. Keywords: coronavirus; SARS coronavirus; SARS-CoV-2; genomic characterization; phylogenetic evolution.