ChAdOx1 nCoV-19/AZD1222 is an approved adenovirus-based vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) currently being deployed globally. Previous studies in rhesus macaques ...revealed that intramuscular vaccination with ChAdOx1 nCoV-19/AZD1222 provided protection against pneumonia but did not reduce shedding of SARS-CoV-2 from the upper respiratory tract. Here, we investigated whether intranasally administered ChAdOx1 nCoV-19 reduces detection of virus in nasal swabs after challenging vaccinated macaques and hamsters with SARS-CoV-2 carrying a D614G mutation in the spike protein. Viral loads in swabs obtained from intranasally vaccinated hamsters were decreased compared to control hamsters, and no viral RNA or infectious virus was found in lung tissue after a direct challenge or after direct contact with infected hamsters. Intranasal vaccination of rhesus macaques resulted in reduced virus concentrations in nasal swabs and a reduction in viral loads in bronchoalveolar lavage and lower respiratory tract tissue. Intranasal vaccination with ChAdOx1 nCoV-19/AZD1222 reduced virus concentrations in nasal swabs in two different SARS-CoV-2 animal models, warranting further investigation as a potential vaccination route for COVID-19 vaccines.
Middle East respiratory syndrome coronavirus (MERS-CoV) infects humans and dromedary camels and is responsible for an ongoing outbreak of severe respiratory illness in humans in the Middle East. ...Although some mutations found in camel-derived MERS-CoV strains have been characterized, most natural variation found across MERS-CoV isolates remains unstudied. We report on the environmental stability, replication kinetics, and pathogenicity of several diverse isolates of MERS-CoV, as well as isolates of severe acute respiratory syndrome coronavirus 2, to serve as a basis of comparison with other stability studies. Although most MERS-CoV isolates had similar stability and pathogenicity in our experiments, the camel-derived isolate C/KSA/13 had reduced surface stability, and another camel isolate, C/BF/15, had reduced pathogenicity in a small animal model. These results suggest that although betacoronaviruses might have similar environmental stability profiles, individual variation can influence this phenotype, underscoring the need for continual global viral surveillance.
Animal host–microbe interactions are a relevant concern for wildlife conservation, particularly regarding generalist pathogens, where domestic host species can play a role in the transmission of ...infectious agents, such as viruses, to wild animals. Knowledge on viral circulation in wild host species is still scarce and can be improved by the recent advent of modern molecular approaches. We aimed to characterize the fecal virome and identify viruses of potential conservation relevance of diarrheic free‐ranging wolves and sympatric domestic dogs from Central Portugal, where a small and threatened wolf population persists in a highly anthropogenically modified landscape. Using viral metagenomics, we screened diarrheic stools collected from wolves (n = 8), feral dogs (n = 4), and pet dogs (n = 6), all collected within wolf range. We detected novel highly divergent viruses as well as known viral pathogens with established effects on population dynamics, including canine distemper virus, a novel bocavirus, and canine minute virus. Furthermore, we performed a 4‐year survey for the six wolf packs comprising this endangered wolf population, screening 93 fecal samples from 36 genetically identified wolves for canine distemper virus and the novel bocavirus, previously identified using our metagenomics approach. Our novel approach using metagenomics for viral screening in noninvasive samples of wolves and dogs has profound implications on the knowledge of both virology and wildlife diseases, establishing a complementary tool to traditional screening methods for the conservation of threatened species.
In diarrheic stools collected from wolves (n = 8), feral dogs (n = 4), and pet dogs (n = 6), all collected within wolf range, we detected novel highly divergent viruses as well as known viral pathogens with established population dynamics effects, including canine distemper virus, a novel bocavirus, and canine minute virus. Furthermore, we surveyed all six wolf packs comprising this endangered wolf population, screening 95 fecal samples from 37 genetically identified wolves for canine distemper virus and a bocavirus, which were previously identified using our metagenomics approach. Wolf photo credits to Artur Oliveira (Centro de Recuperação do Lobo Ibérico).
Rotaviruses (RVs) are classified into eight species/groups (RVA–RVH) according to the migration patterns of their 11 genome segments, as well as by serological and molecular properties of Viral ...Protein 6 (VP6). In 1997 a new unclassified RV was reported infecting adults in Bangladesh and China. This virus was initially named novel adult diarrhoea rotavirus (ADRV-N), but later renamed as RVH. Since then, RVH has been detected in humans only very sporadically. However, RVH is increasingly being detected in pig populations in the USA, Brazil and Japan, but not yet in Africa. Unfortunately, whole genome sequence data of porcine RVH strains in GenBank is currently restricted to a single strain (SKA-1) from Japan.
Porcine diarrhoeic samples were collected in South Africa and analysed for rotavirus using an RVA ELISA and electropherotyping by PAGE. One sample displayed a 4:2:1:1:1:1:1 migration pattern, typical for RVH. In order to further investigate this strain, sequence-independent amplification followed by random sequencing using the 454/Roche GS FLX Sequencer was performed, resulting in the second complete porcine RVH strain (MRC-DPRU1575) available in databases.
Phylogenetically, all segments of MRC-DPRU1575 clustered closely with the SKA-1 strain and in some segments with known porcine RVH strains from Brazil and the USA. In contrast, the porcine RVH strains were only distantly related to human RVH strains from Asia and a partial RVH-like strain recently detected in bats from Cameroon.
Overall, strain MRC-DPRU1575 is the first complete genome of a porcine RVH from Africa and allows for the development of improved RVH screening methods. Our analyses indicate that RVH strains cluster according to their host species, not suggesting any evidence of recent interspecies transmission events. However, more RVH genomes from a wider host range are needed to better understand their evolutionary pathways and zoonotic potential.
•Study reports the first rotavirus group H (RVH) from Africa.•The strain is the first analysed compete porcine RVH genome globally.•Data will allow for improved RVH screening possibilities.
In the past two decades, three coronaviruses with ancestral origins in bats have emerged and caused widespread outbreaks in humans, including severe acute respiratory syndrome coronavirus 2 ...(SARS-CoV-2). Since the first SARS epidemic in 2002-2003, the appreciation of bats as key hosts of zoonotic coronaviruses has advanced rapidly. More than 4,000 coronavirus sequences from 14 bat families have been identified, yet the true diversity of bat coronaviruses is probably much greater. Given that bats are the likely evolutionary source for several human coronaviruses, including strains that cause mild upper respiratory tract disease, their role in historic and future pandemics requires ongoing investigation. We review and integrate information on bat-coronavirus interactions at the molecular, tissue, host and population levels. We identify critical gaps in knowledge of bat coronaviruses, which relate to spillover and pandemic risk, including the pathways to zoonotic spillover, the infection dynamics within bat reservoir hosts, the role of prior adaptation in intermediate hosts for zoonotic transmission and the viral genotypes or traits that predict zoonotic capacity and pandemic potential. Filling these knowledge gaps may help prevent the next pandemic.
A novel Hendra virus variant, genotype 2, was recently discovered in a horse that died after acute illness and in Pteropus flying fox tissues in Australia. We detected the variant in flying fox ...urine, the pathway relevant for spillover, supporting an expanded geographic range of Hendra virus risk to horses and humans.
SARS-CoV-2 transmits principally by air; contact and fomite transmission may also occur. Variants of concern are more transmissible than ancestral SARS-CoV-2. We found indications of possible ...increased aerosol and surface stability for early variants of concern, but not for the Delta and Omicron variants. Stability changes are unlikely to explain increased transmissibility.
Knowledge of the dynamics and genetic diversity of Nipah virus circulating in bats and at the human-animal interface is limited by current sampling efforts, which produce few detections of viral RNA. ...We report a series of investigations at Pteropus medius bat roosts identified near the locations of human Nipah cases in Bangladesh during 2012–2019. Pooled bat urine was collected from 23 roosts; 7 roosts (30%) had >1 sample in which Nipah RNA was detected from the first visit. In subsequent visits to these 7 roosts, RNA was detected in bat urine up to 52 days after the presumed exposure of the human case-patient, although the probability of detection declined rapidly with time. These results suggest that rapidly deployed investigations of Nipah virus shedding from bat roosts near human cases could increase the success of viral sequencing compared with background surveillance and could enhance understanding of Nipah virus ecology and evolution.
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