The protection of CoronaVac against the infection of wild-type SARS-CoV-2(WH-09)or Omicron variant in nude-hACE2 mice

Background:Immunocompromised individuals have an increased risk of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection and severe outcomes,but we pay less attention to these people.Athymic nude mice are a murine strain with a spontaneous deficiency of the Foxn1 gene,which can result in thymic degeneration or its absence,leading to immunosuppression and a decrease in the number of T cells,and are widely used in preclinical evaluations of disease in immunocompromised populations.Methods:We investigated the protection of the coronavirus disease 2019(COVID-19)inactivated vaccine(CoronaVac)against the infection of wild-type SARS-CoV-2(WH-09)or Omicron variant utilizing a hybrid-type nude-hACE2 mouse model.Results:Compared with nude-hACE2/W mice,the viral load in the brain and lung tissue of nude-hACE2 mice(nude-hACE2/WV)infected with WH-09 after vaccination significantly decreased,and the histopathological changes were also reduced.The viral load in the brain and lung tissue of nude-hACE2 mice(nude-hACE2/OV)infected with the Omicron variant after vaccination was lower than that in nude-hACE2/O,but histopathological symptoms did not improve significantly.Conclusion:CoronaVac provides some protection against infection of both WH-09 and the Omicron variant in the nude-hACE2 mice.Our findings aimed to provide a reference for vaccination against SARS-CoV-2 in immunocompromised populations.

SARS-CoV-2 infection aggravates chronic comorbidities of cardiovascular diseases and diabetes in mice

Background:Cardiovascular diseases(CVDs)and diabetes mellitus(DM)are top two chronic comorbidities that increase the severity and mortality of COVID-19.However,how SARS-CoV-2 alters the progression of chronic diseases remain unclear.Methods:We used adenovirus to deliver h-ACE2 to lung to enable SARS-CoV-2 infection in mice.SARS-CoV-2’s impacts on pathogenesis of chronic diseases were studied through histopathological,virologic and molecular biology analysis.Results:Pre-existing CVDs resulted in viral invasion,ROS elevation and activation of apoptosis pathways contribute myocardial injury during SARS-CoV-2 infection.Viral infection increased fasting blood glucose and reduced insulin response in DM model.Bone mineral density decreased shortly after infection,which associated with impaired PI3K/AKT/mTOR signaling.Conclusion:We established mouse models mimicked the complex pathological symptoms of COVID-19 patients with chronic diseases.Pre-existing diseases could impair the inflammatory responses to SARS-CoV-2 infection,which further aggravated the pre-existing diseases.This work provided valuable information to better understand the interplay between the primary diseases and SARS-CoV-2 infection.

The effects of inactivated SARS-CoV-2 vaccination and subsequent infection of pregnant mice on the behaviors of offspring

The mass inoculation of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)vaccines to induce herd immunity is one of the most effective measures we can deploy in the fight against coronavirus disease 2019(COVID-19).Pregnant women are prone to a higher risk of COVID-19,and maternal infection is a risk fac-tor for a range of neurological disorders leading to abnormal behavior in adulthood.However,there are limited clinical data to support whether vaccination or infection post-immunization in pregnant women can affect the behavioral cognition of fetuses in adulthood.In this study,human angiotensin-converting enzyme 2 pregnant mice(F0 generation)were immunized with CoronaVac and then infected with SARS-CoV-2.Subsequently,we analyzed the behavioral cognition of their adult offspring(F1 gen-eration)using the open-field test and Morris water maze test.The adult F1 generation did not exhibit any impairments in spontaneous locomotor activity or spatial refer-ence memory.

Laboratory biosafety emergency management for SARS-CoV-2

A biosafety laboratory is a prerequisite for studying emerging infectious diseases.Safe and effective operation in laboratories and the handling of pathogens determine the safety of the personnel,pathogens,and the environment in the laboratory,which are among the key factors for successful experimentation.In this article,we aimed to provide ideas for the emergency management of biosafety laboratories,including a discussion on the urgency of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)related experimental activities,tracking clinical information,taking emergency measures,revision of the risk assessment process,and standardization of personal protective equipment and personnel behavior standards.