ABSTRACT
Since May 2022, Monkeypox, a zoonotic Orthopox DNA virus was reported in more than 102 countries indicating expansion of its geographic range. We analyzed the complete genomes sequences of Monkeypox cases from Kerala (n=5 travelled from UAE) and Delhi (n=5 no travel history), India confirmed during July to August 2022. All the retrieved MPXV sequences from India covering 90 to 99% genome belong to A.2 lineage of clade IIb. The A.2 MPXV lineage divided in three sub clusters; first cluster Kerala n=5, Delhi n=2 aligned with the USA-2022 ON674051.1; while second of Delhi n=3 aligned with USA-2022 ON675438.1 and third consists of the UK, USA and Thailand. Recent update in MPXV lineage designated all the five sequences from Kerala as A.2.1. In addition to known 16 single nucleotide polymorphisms (SNPs) along with 13 APOBEC3 cytosine deaminase activity determined specific lineage defining mutations in A.2 lineage, 25 additional APOBEC3 mutations were found in 10 reported sequences. The study emphasizes need of enhancing genomic surveillance to understand the mutation and its linkage.
ABSTRACT
The immunity acquired after natural infection or vaccinations against SARS-CoV-2 tend to wane with time. Vaccine effectiveness also varies with the variant of infection. Here, we compared the protective efficacy of COVAXIN(R) following 2 and 3 dose immunizations against the Delta variant and also studied the efficacy of COVAXIN(R) against Omicron variants in a Syrian hamster model. The antibody response, clinical observations, viral load reduction and lung disease severity after virus challenge were studied. Protective response in terms of the reduction in lung viral load and lung lesions were observed in both the 2 dose as well as 3 doses COVAXIN(R) immunized group when compared to placebo group following the Delta variant challenge. In spite of the comparable neutralizing antibody response against the homologous vaccine strain in both the 2 dose and 3 dose immunized groups, considerable reduction in the lung disease severity was observed in the 3 dose immunized group post Delta variant challenge indicating the involvement of cell mediated immune response also in protection. In the vaccine efficacy study against the Omicron variants i.e., BA.1 and BA.2, lesser virus shedding, lung viral load and lung disease severity were observed in the immunized groups in comparison to the placebo groups. The present study shows that administration of COVAXIN(R) booster dose will enhance the vaccine effectiveness against the Delta variant infection and give protection against the Omicron variants BA.1.1 and BA.2.
ABSTRACT
BackgroundWe report here a Nipah virus (NiV) outbreak in Kozhikode district of Kerala state, India which had caused fatal encephalitis in an adolescent male and the outbreak response which led to the successful containment of the disease and the related investigations. MethodsQuantitative real-time RT-PCR, ELISA based antibody detection and whole genome sequencing were performed to confirm the Nipah virus infection. Contacts of the index case were traced and isolated based on risk categorization. Bats from the areas near the epicenter of the outbreak were sampled for throat swabs, rectal swabs and blood samples for Nipah virus screening by real time RT-PCR and anti-Nipah virus bat IgG ELISA. Plaque reduction neutralization test was performed for the detection of neutralizing antibodies. ResultsNipah viral RNA and anti-NiV IgG antibodies were detected in the serum of the index case. Rapid establishment of an onsite NiV diagnostic facility and contact tracing helped in quick containment of the outbreak. NiV sequences retrieved from the clinical specimen of the index case formed a sub-cluster with the earlier reported Nipah I genotype sequences from India with more than 95% similarity. Anti-NiV IgG positivity could be detected in 21% of Pteropus medius and 37.73% of Rousettus leschenaultia. Neutralizing antibodies against NiV could be detected in P.medius. ConclusionsStringent surveillance and awareness campaigns needs to be implemented in the area to reduce human-bat interactions and minimize spill over events which can lead to sporadic outbreaks of NiV.
ABSTRACT
The study investigates the replication cycle and transcriptional pattern of the B.1.1.7 variant. It was observed that the B.1.1.7 variant required a longer maturation time. The transcriptional response demonstrated higher expression of ORF6 and ORF8 compared to nucleocapsid transcript till the eclipse period which might influence higher viral replication. The number of infectious viruses titer is higher in the B.1.1.7, despite a lesser copy number than B.1, indicating higher infectivity.
ABSTRACT
The emergence of SARS-CoV-2 variants has posed a serious challenge to public health system and vaccination programs across the globe. We have studied the pathogenicity and virus shedding pattern of the SARS-CoV-2 VOC 202012/01 and compared with D614G variant in Syrian hamsters. VOC 202012/01 could produce disease in hamsters characterized by body weight loss and respiratory tract tropism but mild lung pathology. Further, we also documented that neutralizing antibodies developed against VOC 202012/01 could equally neutralize D614G variant. Higher load of VOC 202012/01 in the nasal wash specimens was observed during the first week of infection outcompeting the D614G variant. The findings suggest increased fitness of VOC 202012/01 to the upper respiratory tract which could lead to higher transmission. Further investigations are needed to understand the transmissibility of new variants. One-Sentence SummarySARS-CoV-2 VOC 202012/01 infected hamsters demonstrated high viral RNA shedding through the nasal secretions and significant body weight loss with mild lung pathology compared to the D614G variant.
