Immunological evaluation of an inactivated SARS-CoV-2 vaccine in rhesus macaques.

Because of the relatively limited understanding of coronavirus disease 2019 (COVID-19) pathogenesis, immunological analysis for vaccine development is needed. Mice and macaques were immunized with an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine prepared by two inactivators. Various immunological indexes were tested, and viral challenges were performed on day 7 or 150 after booster immunization in monkeys. This inactivated SARS-CoV-2 vaccine was produced by sequential inactivation with formaldehyde followed by propiolactone. The various antibody responses and specific T cell responses to different viral antigens elicited in immunized animals were maintained for longer than 150 days. This comprehensive immune response could effectively protect vaccinated macaques by inhibiting viral replication in macaques and substantially alleviating immunopathological damage, and no clinical manifestation of immunopathogenicity was observed in immunized individuals during viral challenge. This candidate inactivated vaccine was identified as being effective against SARS-CoV-2 challenge in rhesus macaques.

Assessing the Spectral Properties of Sunlit and Shaded Components in Rice Canopies with Near-Ground Imaging Spectroscopy Data.

Monitoring the components of crop canopies with remote sensing can help us understand the within-canopy variation in spectral properties and resolve the sources of uncertainties in the spectroscopic estimation of crop foliar chemistry. To date, the spectral properties of leaves and panicles in crop canopies and the shadow effects on their spectral variation remain poorly understood due to the insufficient spatial resolution of traditional spectroscopy data. To address this issue, we used a near-ground imaging spectroscopy system with high spatial and spectral resolutions to examine the spectral properties of rice leaves and panicles in sunlit and shaded portions of canopies and evaluate the effect of shadows on the relationships between spectral indices of leaves and foliar chlorophyll content. The results demonstrated that the shaded components exhibited lower reflectance amplitude but stronger absorption features than their sunlit counterparts. Specifically, the reflectance spectra of panicles had unique double-peak absorption features in the blue region. Among the examined vegetation indices (VIs), significant differences were found in the photochemical reflectance index (PRI) between leaves and panicles and further differences in the transformed chlorophyll absorption reflectance index (TCARI) between sunlit and shaded components. After an image-level separation of canopy components with these two indices, statistical analyses revealed much higher correlations between canopy chlorophyll content and both PRI and TCARI of shaded leaves than for those of sunlit leaves. In contrast, the red edge chlorophyll index (CIRed-edge) exhibited the strongest correlations with canopy chlorophyll content among all vegetation indices examined regardless of shadows on leaves. These findings represent significant advances in the understanding of rice leaf and panicle spectral properties under natural light conditions and demonstrate the significance of commonly overlooked shaded leaves in the canopy when correlated to canopy chlorophyll content.

[Genomic characteristics of coxsackievirus B1 MSH/KM9/2009 strain isolated in Yunnan, China].

To characterize the complete genome sequence of coxsackievirus B1 (CVB1) MSH/KM9/2009 strain isolated from Yunnan, China,2009. Eight overlapping clones covering the whole viral genome (excluding the poly-A tail) were obtained by RT-PCR and sequenced, and their nucleotide and amino acid sequences were compared with other known CVB1 strains. The genome of the CVB1 MSH/KM9/2009 strain had 7384 nucleotides in length, and contained a 741nt non-translated region (NTR) at the 5' end and a 94nt NTR at the 3' end. The entire open reading frame contained 6 549 nt, encoding a 2 183-aa polyprotein. In the coding region, there was no nucleotide deletion or insertion, but some changes of amino acid were unique. The complete genome sequence alignments showed that the CVB1 isolate MSH/KM9/2009 strain shared the highest nucleotide (80.9%, 81.6%, 80.5% and 80%) and amino acid (95.6%, 95.8%, 96.2% and 95.6%) identities to the CVB1 M16560, pmMC, Tucson B1 and CVB1Nm strain, respectively. Phylogenetic tree analysis showed that the MSH/KM9/2009, CVB1 M16560, pmMC, Tucson B1 and CVB1Nm strain clustered into same group. The newly isolated CVB1 strain MSH/KM9/2009 from Yunnan Province belonged to genotype CVB1.

[Complete nucleotide sequence of a human echovirus 6 strain KM57-09 isolated in Yunnan, China, in 2009].

OBJECTIVE: To analyze the genetic characterization of the complete genome from a human echovirus 6 (Echo6) strain KM57-09 isolated in Yunnan, China, in 2009. METHODS: Using the RT-PCR, eight fragments containing about 1000 nucleotides which covered the whole viral genome were sequenced. The sequences were aligned with other reference enterovirus sequences downloaded from the GenBank, using Mega 5.05, RDP 3 and SimPlot 3.5.1 softwares. RESULTS: Similar to the other human enterovirus, KM57-09 isolate genome appeared to have 7419 nucleotides in length, encoding for 2191 amino acids. In the complete genome, the rates of homology on nucleotide and amino acid among the seven Echo6 isolates were 79.3% - 80.2% and 93.3% - 94.4%, respectively as well as 79.3% and 93.6% of the rates of homology when compared with that of D' Amor prototype strain. In different segment of genome. The 2C-3A genome region was most similar to the HN-2-E25 strain, the 5' UTR, VP4, 3D and 3' UTR genome region were most similar to the CoxB5-Henan-2010. In the VP1 gene, the rates of homology on nucleotide and amino acid among the China isolates were 80.0% - 96.0% and 95.8% - 99.0%, respectively, and showed 77.6% - 96.0% and 95.2% - 99.0% of the rates on homology when compared to the other Echo6 reference strains isolated from other countries or areas, respectively. RESULTS: from phylogenetic analysis showed that the Echo6 formed five distinct groups, A-E. The KM57-09 strain belonged to clade E. The nucleotide divergence between clades was 15.6% - 23.3%. The putative recombinant event for KM57-09 was detected with RDP 3, SimPlot 3.5.1 and 3D sequence phylogenetic analysis. CONCLUSION: All the Echo6 isolates could be divided into five clades, the KM57-09 strain belonged to Clade E. The Echo6 strains isolated in China were contributed to several different chains of transmission.