ABSTRACT
We present a low‐altitude satellite survey of power line harmonic radiation (PLHR) at 50 Hz over Mainland China. We analyzed the month‐to‐month variation pattern in PLHR occurrence rate and further analyzed its correlation with some influencing factors (i.e., solar radiation, lightning flashes, and electricity consumption) using CSES satellite electric field data from 2019 to 2021. We also investigate the response of PLHR occurrence rate to COVID‐19. The statistical results show the dayside PLHR occurrence rate decreasing from winter to summer solstice and increasing from summer to winter solstice, which indicates it is controlled by the solar radiation. The nightside variation is more complex, which may be due to many sources that could influence the nightside lower ionosphere. The PLHR occurrence rate significantly decreased over Mainland China in February 2020, which is because of the significant decrease in electricity consumption due to the suspension of industrial production caused by COVID‐19.Alternate :Plain Language SummaryPower line harmonic radiation (PLHR) is the electromagnetic waves radiated by electric power systems at harmonic frequencies of 50 or 60 Hz, depending on the frequency of the system on the ground. Previous research mainly focuses on identification of individual PLHR events and their subsequent analysis. However, the number of base‐frequency PLHR signal events is the most abundant, which is suitable for the statistical study of PLHR occurrence rate and its variation pattern, and further study of the factors affecting its variation pattern. In this paper, we use 3 years of electric field data from the China Seismo‐Electromagnetic Satellite (CSES) which is an LEO satellite launched into orbit in February 2018 to investigate the month‐to‐month variation pattern of PLHR occurrence rate over Mainland China and its correlation with the influencing factors. The response of PLHR occurrence rate to COVID‐19 are also investigated.
ABSTRACT
Summary Background The ReCOV is a recombinant trimeric two-component SARS-CoV-2 subunit vaccine adjuvanted with BFA03. We report the preliminary safety and immunogenicity results for the ReCOV. Methods This first in human, randomized, double-blind, placebo-controlled phase I study, was conducted at 2 study sites in New Zealand. Subjects were stratified into two age cohorts (18-55 years and 56-80 years old) and then randomly assigned in a 4:1 ratio to receive two 0.5 mL intramuscular doses of the ReCOV vaccine (20µg or 40µg, adjuvanted with BFA03 in each) or placebo, 21 days apart. The primary endpoints were incidence of solicited local and systemic adverse events (AEs) and unsolicited AEs after each dose; incidence of serious adverse events (SAEs) up to 30 days after the second dose; changes in clinical laboratory tests from baseline up to 7 days after each dose; and changes in vital signs from baseline up to 30 days after the second dose. The key secondary endpoints for immunogenicity were neutralizing antibody titers against SARS-CoV-2, S1 receptor binding domain (RBD) and N-terminal domain (NTD) IgG titers post-vaccination. The T cell-specific immune response elicited by ReCOV were also evaluated. The trial was registered with ClinicalTrials.gov ( NCT04818801 ). Findings One hundred participants (50 for each age group) were randomized. The incidence of solicited local AEs in 20μg ReCOV, 40μg ReCOV, and pooled placebo group among younger adults were 60.0%, 70.0%, and 10.0%, respectively, while among older adults were 55.0%, 84.2%, and 10.0%, respectively. The incidence of solicited systemic AEs in 20μg ReCOV, 40μg ReCOV, and pooled placebo group among younger adults were 60.0%, 60.0%, and 30.0%, respectively, while among older adults were 50.0%, 52.6%, and 50.0%, respectively. All solicited AEs and unsolicited AEs were mild. No vaccination-related SAE, adverse events of special interest, and AE leading to early discontinuation were reported. ReCOV elicited SARS-CoV-2 neutralizing antibody after the first vaccination, which were increased further after the second vaccination irrespective of dose and age groups. The neutralizing antibody against wild-type SARS-CoV-2 peaked at 14 days post the second vaccination in both 20µg and 40µg ReCOV groups, with GMT of 1643.17 IU/mL and 1289.21 IU/mL among younger adults, and 1122.32 IU/mL and 680.31 IU/mL among older adults, respectively. Similarly, both anti-RBD and anti-NTD specific IgG were elicited after the first vaccination, and peaked at 14 days after the second vaccination. T helper 1 biased cellular responses were observed after ReCOV vaccinations. Interpretation Both 20 and 40µg ReCOV showed good safety profiles and elicited strong immune responses in the younger and the older adults. The results of this study support the accelerated development of ReCOV. Funding Jiangsu Recbio Technology Co., Ltd.
ABSTRACT
Advanced mRNA vaccines play vital roles against SARS-CoV-2. However, due to the poor stability, most current mRNA delivery platforms need to be stored at -20 {degrees}C or -70 {degrees}C. Here we present lyophilized thermostable mRNA loaded lipid nanoparticles, which could be stored at room temperature with long-term stability. We demonstrate the applicability of lyophilization techniques to different mRNA sequences and lipid components. Three lyophilized vaccines targeting wild-type, Delta and Omicron SARS-CoV-2 variant were prepared and demonstrated to be able induce high-level of IgG titer and neutralization response. In the Delta challenge in vivo experiment, the lyophilized mRNA vaccine successfully protected the mice from infection and clear the virus. This lyophilization platform could significantly improve the accessibility of mRNA vaccine or therapeutics, particularly in remote regions.
ABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to significant public health, economic and social problems. Development of effective vaccines is still a priority to contain the virus and end the global pandemic. In this study, we reported that ReCOV, a recombinant trimeric NTD and RBD two-component SARS-CoV-2 subunit vaccine adjuvanted with BFA03 (an AS03-like squalene adjuvant), induced high levels of neutralizing antibodies against SARS-CoV-2 and the circulating variants in mice, rabbits and rhesus macaques. Notably, two-dose immunizations of ReCOV provided complete protection against challenge with SARS-CoV-2 in hACE2 transgenic mice and rhesus macaques, without observable antibody-dependent enhancement of infection. These results support further clinical development of ReCOV and the vaccine is currently being evaluated in a phase I clinical trial in New Zealand ( NCT04818801 ).