SARS-CoV-2 spillover transmission due to recombination event

Molecular surveillance of potential SARS-CoV-2 reservoir hosts in wildlife rehabilitation centers

BACKGROUND

The COVID-19 pandemic, caused by SARS-CoV-2 infection, has become the most devastating zoonotic event in recent times, with negative impacts on both human and animal welfare as well as on the global economy. Although SARS-CoV-2 is considered a human virus, it likely emerged from animals, and it can infect both domestic and wild animals. This constitutes a risk for human and animal health including wildlife with evidence of SARS-CoV-2 horizontal transmission back and forth between humans and wild animals.

AIM

Molecular surveillance in different wildlife rehabilitation centers and wildlife associated institutions in Chile, which are critical points of animal-human interaction and wildlife conservation, especially since the aim of wildlife rehabilitation centers is to reintroduce animals to their original habitat.

MATERIALS AND METHODS

The survey was conducted in six WRCs and three wildlife associated institutions. A total of 185 samples were obtained from 83 individuals belonging to 15 different species, including vulnerable and endangered species. Each specimen was sampled with two different swabs: one oropharyngeal or nasopharyngeal according to the nostril diameter, and/or a second rectal sample. RNA was extracted from the samples and two different molecular assays were performed: first, a conventional RT-PCR with pan-coronavirus primers and a second SARS-CoV-2 qPCR targeting the N and S genes.

RESULTS

All 185 samples were negative for SARS-CoV-2.

CLINICAL RELEVANCE

This study constitutes the first report on the surveillance of SARS-CoV-2 from wildlife treated in rehabilitation centers in Chile, and supports the biosafety procedures adopted in those centers.

A pangolin-origin SARS-CoV-2-related coronavirus: infectivity, pathogenicity, and cross-protection by preexisting immunity

Virus spillover remains a major challenge to public health. A panel of SARS-CoV-2-related coronaviruses have been identified in pangolins, while the infectivity and pathogenicity of these pangolin-origin coronaviruses (pCoV) in humans remain largely unknown. Herein, we comprehensively characterized the infectivity and pathogenicity of a recent pCoV isolate (pCoV-GD01) in human cells and human tracheal epithelium organoids and established animal models in comparison with SARS-CoV-2. pCoV-GD01 showed similar infectivity to SARS-CoV-2 in human cells and organoids. Remarkably, intranasal inoculation of pCoV-GD01 caused severe lung pathological damage in hACE2 mice and could transmit among cocaged hamsters. Interestingly, in vitro neutralization assays and animal heterologous challenge experiments demonstrated that preexisting immunity induced by SARS-CoV-2 infection or vaccination was sufficient to provide at least partial cross-protection against pCoV-GD01 challenge. Our results provide direct evidence supporting pCoV-GD01 as a potential human pathogen and highlight the potential spillover risk.

Persisting Vaccine Hesitancy in Africa: The Whys, Global Public Health Consequences and Ways-Out-COVID-19 Vaccination Acceptance Rates as Case-in-Point

Vaccine hesitancy (VH) is the seventh among the WHO's top 10 threats to global public health, which has continued to perpetuate the transmission of vaccine preventable diseases (VPDs) in Africa. Consequently, this paper systematically reviewed COVID-19 vaccine acceptance rates (VARs)-including the vaccine uptake and vaccination intention-in Africa from 2020 to 2022, compared the rates within the five African regions and determined the context-specific causes of VH in Africa. Generally, COVID-19 VARs ranged from 21.0% to 97.9% and 8.2% to 92.0% with mean rates of 59.8 ± 3.8% and 58.0 ± 2.4% in 2021 and 2022, respectively. Southern and eastern African regions had the top two VARs of 83.5 ± 6.3% and 68.9 ± 6.6% in 2021, and 64.2 ± 4.6% and 61.2 ± 5.1% in 2022, respectively. Based on population types, healthcare workers had a marginal increase in their mean COVID-19 VARs from 55.5 ± 5.6% in 2021 to 60.8 ± 5.3% in 2022. In other populations, the mean VARs decreased from 62.7 ± 5.2% in 2021 to 54.5 ± 4% in 2022. As of 25 October 2022, Africa lags behind the world with only 24% full COVID-19 vaccinations compared to 84%, 79% and 63% reported, respectively, in the Australian continent, upper-middle-income countries and globally. Apart from the problems of confidence, complacency, convenience, communications and context, the context-specific factors driving COVID-19 VH in Africa are global COVID-19 vaccine inequality, lack of vaccine production/maintenance facilities, insecurity, high illiteracy level, endemic corruption, mistrust in some political leaders, the spreading of unconfirmed anti-vaccination rumors and political instability. With an overall mean COVID-19 acceptance rate of 58%, VH still subsists in Africa. The low VARs in Africa have detrimental global public health implications, as it could facilitate the emergence of immune invading SARS-CoV-2 variants of concern, which may spread globally. Consequently, there is a need to confront these challenges frontally and engage traditional and religious leaders in the fight against VH in Africa, to restore public trust in the safety and efficacy of vaccines generally. As the availability of COVID-19 vaccines improves, the vaccination of pets and zoo-animals from which reverse zoonotic transmission of SARS-CoV-2 have been reported is recommended, to limit the evolution and spread of new variants of concern and avert possible SARS-CoV-2 epizootic or panzootic diseases in susceptible animal species.

Investigating SARS-CoV-2 Susceptibility in Animal Species: A Scoping Review

In the early stages of response to the SARS-CoV-2 pandemic, it was imperative for researchers to rapidly determine what animal species may be susceptible to the virus, under low knowledge and high uncertainty conditions. In this scoping review, the animal species being evaluated for SARS-CoV-2 susceptibility, the methods used to evaluate susceptibility, and comparing the evaluations between different studies were conducted. Using the PRISMA-ScR methodology, publications and reports from peer-reviewed and gray literature sources were collected from databases, Google Scholar, the World Organization for Animal Health (OIE), snowballing, and recommendations from experts. Inclusion and relevance criteria were applied, and information was subsequently extracted, categorized, summarized, and analyzed. Ninety seven sources (publications and reports) were identified which investigated 649 animal species from eight different classes: Mammalia, Aves, Actinopterygii, Reptilia, Amphibia, Insecta, Chondrichthyes, and Coelacanthimorpha. Sources used four different methods to evaluate susceptibility, in silico, in vitro, in vivo, and epidemiological analysis. Along with the different methods, how each source described "susceptibility" and evaluated the susceptibility of different animal species to SARS-CoV-2 varied, with conflicting susceptibility evaluations evident between different sources. Early in the pandemic, in silico methods were used the most to predict animal species susceptibility to SARS-CoV-2 and helped guide more costly and intensive studies using in vivo or epidemiological analyses. However, the limitations of all methods must be recognized, and evaluations made by in silico and in vitro should be re-evaluated when more information becomes available, such as demonstrated susceptibility through in vivo and epidemiological analysis.

Microbial ecology and evolution is key to pandemics: using the coronavirus model to mitigate future public health challenges

Pandemics are global challenges that lead to total disruption of human activities. From the inception of human existence, all pandemics have resulted in loss of human lives. The coronavirus disease caused by SAR-CoV-2 began in China and is now at the global scale with an increase in mortality and morbidity. Numerous anthropogenic activities have been implicated in the emergence and severity of pandemics, including COVID-19. These activities cause changes in microbial ecology, leading to evolution due to mutation and recombination. This review hypothesized that an understanding of these anthropogenic activities would explain the dynamics of pandemics. The recent coronavirus model was used to study issues leading to microbial evolution, towards preventing future pandemics. Our review highlighted anthropogenic activities, including deforestation, mining activities, waste treatment, burning of fossil fuel, as well as international travels as drivers of microbial evolution leading to pandemics. Furthermore, human-animal interaction has also been implicated in pandemic incidents. Our study recommends substantial control of such anthropogenic activities as having been highlighted as ways to reduce the frequency of mutation, reduce pathogenic reservoirs, and the emergence of infectious diseases.

Analysis of SARS-CoV-2 nucleocapsid protein sequence variations in ASEAN countries

BACKGROUND Nucleocapsid (N) protein is one of four structural proteins of SARS-CoV-2  which is known to be more conserved than spike protein and is highly immunogenic. This study aimed to analyze the variation of the SARS-CoV-2 N protein sequences in ASEAN countries, including Indonesia. METHODS Complete sequences of SARS-CoV-2 N protein from each ASEAN country were obtained from Global Initiative on Sharing All Influenza Data (GISAID), while the reference sequence was obtained from GenBank. All sequences collected from December 2019 to March 2021 were grouped to the clade according to GISAID, and two representative isolates were chosen from each clade for the analysis. The sequences were aligned by MUSCLE, and phylogenetic trees were built using MEGA-X software based on the nucleotide and translated AA sequences. RESULTS 98 isolates of complete N protein genes from ASEAN countries were analyzed. The nucleotides of all isolates were 97.5% conserved. Of 31 nucleotide changes, 22 led to amino acid (AA) substitutions; thus, the AA sequences were 94.5% conserved. The phylogenetic tree of nucleotide and AA sequences shows similar branches. Nucleotide variations in clade O (C28311T); clade GR (28881–28883 GGG>AAC); and clade GRY (28881–28883 GGG>AAC and C28977T) lead to specific branches corresponding to the clade within both trees. CONCLUSIONS The N protein sequences of SARS-CoV-2 across ASEAN countries are highly conserved. Most isolates were closely related to the reference sequence originating from China, except the isolates representing clade O, GR, and GRY which formed specific branches in the phylogenetic tree.

Mutation Signatures and In Silico Docking of Novel SARS-CoV-2 Variants of Concern

One year since the first severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China, several variants of concern (VOC) have appeared around the world, with some variants seeming to pose a greater thread to public health due to enhanced transmissibility or infectivity. This study provides a framework for molecular characterization of novel VOC and investigates the effect of mutations on the binding affinity of the receptor-binding domain (RBD) to human angiotensin-converting enzyme 2 (hACE2) using in silico approach. Notable nonsynonymous mutations in RBD of VOC include the E484K and K417N/T that can be seen in South African and Brazilian variants, and N501Y and D614G that can be seen in all VOC. Phylogenetic analyses demonstrated that although the UK-VOC and the BR-VOC fell in the clade GR, they have different mutation signatures, implying an independent evolutionary pathway. The same is true about SA-VOC and COH-VOC felling in clade GH, but different mutation signatures. Combining molecular interaction modeling and the free energy of binding (FEB) calculations for VOC, it can be assumed that the mutation N501Y has the highest binding affinity in RBD for all VOC, followed by E484K (only for BR-VOC), which favors the formation of a stable complex. However, mutations at the residue K417N/T are shown to reduce the binding affinity. Once vaccination has started, there will be selective pressure that would be in favor of the emergence of novel variants capable of escaping the immune system. Therefore, genomic surveillance should be enhanced to find and monitor new emerging SARS-CoV-2 variants before they become a public health concern.