Emerging microbes & infections
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Emerg Microbes Infect · Dec 2021
Heterologous prime-boost: breaking the protective immune response bottleneck of COVID-19 vaccine candidates.
COVID-19 vaccines emerging from different platforms differ in efficacy, duration of protection, and side effects. To maximize the benefits of vaccination, we explored the utility of employing a heterologous prime-boost strategy in which different combinations of the four types of leading COVID-19 vaccine candidates that are undergoing clinical trials in China were tested in a mouse model. ⋯ Moreover, a heterologous prime-boost regimen with an adenovirus vector vaccine also improved Th1-biased T cell responses. Our results provide new ideas for the development and application of COVID-19 vaccines to control the SARS-CoV-2 pandemic.
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Emerg Microbes Infect · Dec 2021
Boosting with heterologous vaccines effectively improves protective immune responses of the inactivated SARS-CoV-2 vaccine.
Since the outbreak of COVID-19, a variety of vaccine platforms have been developed. Amongst these, inactivated vaccines have been authorized for emergency use or conditional marketing in many countries. To further enhance the protective immune responses in populations that have completed vaccination regimen, we investigated the immunogenic characteristics of different vaccine platforms and tried homologous or heterologous boost strategy post two doses of inactivated vaccines in a mouse model. ⋯ In particular, inactivated vaccines showed relatively lower level of neutralizing antibody and T cell responses, but a higher IgG2a/IgG1 ratio compared with other vaccines. Boosting with either recombinant subunit, adenovirus vectored or mRNA vaccine after two-doses of inactivated vaccine further improved both neutralizing antibody and Spike-specific Th1-type T cell responses compared to boosting with a third dose of inactivated vaccine. Our results provide new ideas for prophylactic inoculation strategy of SARS-CoV-2 vaccines.
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Emerg Microbes Infect · Dec 2020
First isolation, in-vivo and genomic characterization of zoonotic variegated squirrel Bornavirus 1 (VSBV-1) isolates.
The variegated squirrel bornavirus 1 (VSBV-1), a member of the family Bornaviridae, was discovered in 2015 in a series of lethal human infections. Screening approaches revealed kept exotic squirrels as the putative source of infection. Infectious virus was successfully isolated by co-cultivation of infected primary squirrel cells with permanent cell lines. ⋯ Sequencing showed minor adaptations within the VSBV-1 genome comparing to the viral genomes from infected squirrels, cell cultures or rat tissues. In conclusion, we were able to generate the first VSBV-1 isolates and provide in vivo animal model data in Lewis rats revealing substantial differences between VSBV-1 and BoDV-1. Furthermore, the presented data are a precondition for insights into the transmission and pathogenesis of this novel zoonotic pathogen.
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Emerg Microbes Infect · Dec 2020
LetterIsolation of infectious SARS-CoV-2 from urine of a COVID-19 patient.
SARS-CoV-2 caused a major outbreak of severe pneumonia (COVID-19) in humans. Viral RNA was detected in multiple organs in COVID-19 patients. ⋯ The virus isolated could infect new susceptible cells and was recognized by its' own patient sera. Appropriate precautions should be taken to avoid transmission from urine.
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Emerg Microbes Infect · Dec 2020
LetterRheumotologitsts' view on the use of hydroxychloroquine to treat COVID-19.
The current pandemic coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) calls urgently for effective therapies. Anti-malarial medicine chloroquine (CQ) and particularly its chemical analogue hydroxychloroquine (HCQ) have been recommended as promising candidate therapeutics that are now under either compassionate off-label use or clinical trials for the treatment of COVID-19 patients. However, there are public concerns and disputes about both the safety and efficacy of CQ and HCQ for this new application. Given the fact that for decades HCQ has been approved as an immunomodulatory drug for the long term treatment of chronic rheumatic diseases, as experienced rheumatologists, we would like to share our thoughts in this regard and trigger a brainstorm among clinical care providers for exchanging their diverse opinions on this urgent topic.