Breadth of SARS-CoV-2 neutralization and protection induced by a nanoparticle vaccine.

Coronavirus vaccines that are highly effective against current and anticipated SARS-CoV-2 variants are needed to control COVID-19. We previously reported a receptor-binding domain (RBD)-sortase A-conjugated ferritin nanoparticle (scNP) vaccine that induced neutralizing antibodies against SARS-CoV-2 and pre-emergent sarbecoviruses and protected non-human primates (NHPs) from SARS-CoV-2 WA-1 infection. Here, we find the RBD-scNP induced neutralizing antibodies in NHPs against pseudoviruses of SARS-CoV and SARS-CoV-2 variants including 614G, Beta, Delta, Omicron BA.1, BA.2, BA.2.12.1, and BA.4/BA.5, and a designed variant with escape mutations, PMS20. Adjuvant studies demonstrate variant neutralization titers are highest with 3M-052-aqueous formulation (AF). Immunization twice with RBD-scNPs protect NHPs from SARS-CoV-2 WA-1, Beta, and Delta variant challenge, and protect mice from challenges of SARS-CoV-2 Beta variant and two other heterologous sarbecoviruses. These results demonstrate the ability of RBD-scNPs to induce broad neutralization of SARS-CoV-2 variants and to protect animals from multiple different SARS-related viruses. Such a vaccine could provide broad immunity to SARS-CoV-2 variants.

Neutralizing antibody vaccine for pandemic and pre-emergent coronaviruses.

Betacoronaviruses caused the outbreaks of severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome, as well as the current pandemic of SARS coronavirus 2 (SARS-CoV-2)1-4. Vaccines that elicit protective immunity against SARS-CoV-2 and betacoronaviruses that circulate in animals have the potential to prevent future pandemics. Here we show that the immunization of macaques with nanoparticles conjugated with the receptor-binding domain of SARS-CoV-2, and adjuvanted with 3M-052 and alum, elicits cross-neutralizing antibody responses against bat coronaviruses, SARS-CoV and SARS-CoV-2 (including the B.1.1.7, P.1 and B.1.351 variants). Vaccination of macaques with these nanoparticles resulted in a 50% inhibitory reciprocal serum dilution (ID50) neutralization titre of 47,216 (geometric mean) for SARS-CoV-2, as well as in protection against SARS-CoV-2 in the upper and lower respiratory tracts. Nucleoside-modified mRNAs that encode a stabilized transmembrane spike or monomeric receptor-binding domain also induced cross-neutralizing antibody responses against SARS-CoV and bat coronaviruses, albeit at lower titres than achieved with the nanoparticles. These results demonstrate that current mRNA-based vaccines may provide some protection from future outbreaks of zoonotic betacoronaviruses, and provide a multimeric protein platform for the further development of vaccines against multiple (or all) betacoronaviruses.

Effect of smartphone app on post-traumatic stress disorder in COVID-19 convalescent patients: A protocol for systematic review and meta-analysis.

BACKGROUND: The outbreak of Coronavirus Disease 2019 (COVID-19) seriously affects humans' health worldwide physically and mentally. Studies revealed that the prevalence of post-traumatic stress disorder (PTSD) increased under this condition. PTSD can change the structure of patients' central nervous system, and increase the risk of anxiety or depression, thus greatly affecting the quality of patients' life and their families. PTSD is preventable, and the effects of early prevention are better. Non-drug intervention can prevent or reduce the psychological sequelae after hospitalization, help patients understand the experience during hospitalization, and be beneficial to their psychological rehabilitation. Whether smartphone app based intervention can be an alternative therapy for PTSD in terms of COVID-19 convalescent patients is still controversial. Therefore, we conducted a meta-analysis and systematic review to evaluate the effects of smartphone app based intervention on PTSD in COVID-19 convalescent patients, so as to provide some guidance for clinical application. METHODS: The literatures that are related to the smartphone app based intervention and PTSD in COVID-19 convalescent patients from inception to February 2021 will be searched. The following databases are our focused areas: ClinicalTrials.gov, Cochrane Central Register of Controlled Trials repositories, PubMed, EmBase, and Web of Science databases. According to the inclusion and exclusion criteria, 2 investigators would independently screen the literature extract data and evaluate the risk of bias in the included studies. Meta-analysis was performed with RevMan5.3 software. RESULTS: The results of this meta-analysis will be submitted to a peer-reviewed journal for publication. CONCLUSION: The conclusion of our study could provide evidence for the judgment of whether smartphone app based intervention is an effective intervention on PTSD in COVID-19 convalescent patients. PROSPERO REGISTRATION NUMBER: CRD42021240340.

The N gene of SARS-CoV-2 was the main positive component in repositive samples from a cohort of COVID-19 patients in Wuhan, China.

BACKGROUND: Repositivity of SARS-CoV-2 nucleic acid in discharged COVID-19 patients was reported recently. However, the characteristics of repositive results are still not well understood, leading to a lack of effective monitoring strategies. METHODS: In the present study, a total of 59 COVID-19 patients were enrolled, and the characteristics of the repositive samples were analyzed. RESULTS: The repositive rate in this cohort was 15.79%. The N gene was the main target gene that was positive in the repositive results as well as in the last positive results of all patients. The median duration from diagnosis to the last positive test was 20 days (IQR, 16-31 days), and the longest duration was 40 days. Repositivity was only observed in IgM single- or both IgM- and IgG-positive patients, instead of IgG single-positive patients. CONCLUSIONS: There was a significant proportion of repositives in the recovered COVID-19 patients, and increasing the required number of negatives for consecutive nucleic acid tests may reduce the incidence of repositives. The recommended monitoring strategy for repositivity is monitoring the N gene in IgM-positive patients. This can ensure high sensitivity while reducing the time and cost of nucleic acid detection.

The effects of chloroquine and hydroxychloroquine on ACE2 related coronavirus pathology and the cardiovascular system: An evidence based review

The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a serious threat to global public health and there is currently no effective antiviral therapy. It has been suggested that Chloroquine (CQ) and hydroxychloroquine (HCQ), which were primarily employed as prophylaxis and treatment for malaria, could be used to treat COVID-19. CQ and HCQ may be potential inhibitors of SARS-CoV-2 entry into host cells, which is mediated via the angiotensin-converting enzyme 2 (ACE2), and may also inhibit subsequent intracellular processes which lead to COVID-19, including damage to the cardiovascular system. However, paradoxically, CQ and HCQ have also been reported to cause damage to the cardiovascular system. In this review, we provide a critical examination of the published evidence. CQ and HCQ could potentially be useful drugs in the treatment of COVID-19 and other ACE2 involved virus infections, but the antiviral effects of CQ and HCQ need to be tested in more well-designed clinical randomized studies and their actions on the cardiovascular system need to be further elucidated. However, even if it were to turn out that CQ and HCQ are not useful drugs in practice, further studies of their mechanism of action could be helpful in improving our understanding of COVID-19 pathology.