key: cord-0889981-gxq3pz28 authors: Mohandas, Sreelekshmy; Yadav, Pragya D; Nyayanit, Dimpal; Shete-Aich, Anita; Sarkale, Prasad; Hundekar, Supriya; Kumar, Sanjay; Lole, Kavita title: Comparison of SARS-CoV-2 VOC 202012/01 (UK variant) and D614G variant transmission by different routes in Syrian hamsters date: 2021-03-26 journal: bioRxiv DOI: 10.1101/2021.03.26.437153 sha: c3f052de3ab503511aa742e96f1f14bae382628c doc_id: 889981 cord_uid: gxq3pz28 Many SARS-CoV-2 variants of concern has been reported recently which were linked to increased transmission. In our earlier study on virus shedding using VOC 202012/01(UK variant) and D614G variant in hamster model, we observed significantly higher viral RNA shedding through nasal wash in case of UK variant. Hence, we compared the transmission of both the UK and D614G variant by various routes in Syrian hamsters to understand whether the high viral RNA shedding could enhance the transmission efficiency of the variant. The current study demonstrated comparable transmission efficiency of both UK and D614G variants of SARS-CoV-2 in Syrian hamsters. . Twenty four hour post infection, 3 donor hamsters were co-housed with a naive hamster (referred to as contact hamster further) in 1: 1 ratio in a new cage to study direct transmission and were observed till 14 DPE for body weight change and any respiratory signs. The contact hamsters exposed with UK variant showed maximum average weight loss of -2.93 ± 0.34 % and with D614G variant showed -4.8± 3.13 % on 8 DPE (Fig. 1A) . The contact hamsters exposed with both variants showed viral gRNA positivity in the samples from 2 nd DPE and peak average viral gRNA load by 2 nd to 4 th DPE ( Figure 1B-D) . This is similar to the pattern of detection reported in intranasal inoculated hamsters with both variants 3, 8 . Titration of nasal wash samples showed consistent presence of virus till 10DPE with comparable titre in hamsters exposed with both variants (Fig. 1E) . As the direct contact transmission, could be contributed by aerosol and fomites, we assessed these routes of transmission alone. To assess the aerosol transmissibility, (Fig. 1A) . The viral gRNA detection was observed from 2 nd DPE and the average viral gRNA peak detection in the nasal wash and faeces was observed on 6 DPE for hamsters exposed with both variants and higher viral load till 10 days (Fig. 1B-D) . The TCID50/ml of the nasal wash samples from 6 to 10DPE showed higher titres (Fig.1E) . For the fomite transmission study, 3 naive hamsters were housed in different cages with soiled bedding of SARS-CoV-2 infected hamster housed for 48 hours following infection. A progressive decrease in body weight till 14 days was observed in fomite contact hamsters of both the variants (Fig. 1A) . The peak average viral gRNA in fomite contact hamsters varied from 6 to 8 DPE in case of UK variant and 4 to 6 DPE with D614G variant (Fig 1B-D) . This is in contrary to an earlier study which reported less efficient fomite transmission by SARS-CoV-2 in hamsters 4 . Even though viral gRNA could be detected till 14DPE, live virus particles could not be detected from 6DPE in case of D614G variant contacts in contrast to UK variant contacts where it could be detected till 10DPE (Fig.1E) . The virus detection in contact hamsters were seen as early as on 2 nd DPE for throat swab (C) nasal wash (D) faeces in hamsters exposed by direct, aerosol and fomite contact. (E)Viral load in nasal wash samples of contact hamsters exposed by direct, aerosol and fomite contact estimated by titration in Vero CCL-81 cells expressed in TCID50. Estimated transmissibility and severity of novel SARS-CoV-2 Variant of Concern 202012/01 in England Comparison of the pathogenicity and virus shedding of SARS CoV-2 VOC 202012/01 and D614G variant in hamster model Pathogenesis and transmission of SARS-CoV-2 in golden hamsters First isolation of SARS-CoV-2 from clinical samples in India Isolation and characterization of VUI-202012/01, a SARS-CoV-2 variant in travellers from the United Kingdom to India Development of in vitro transcribed RNA as positive control for laboratory diagnosis of SARS-CoV-2 in India SARS-CoV-2 D614G variant exhibits efficient replication ex vivo and transmission in vivo Dose-dependent response to infection with SARS-CoV-2 in the ferret model and evidence of protective immunity Immunogenicity and protective efficacy of BBV152, whole virion inactivated SARS-CoV-2 vaccine candidates in the Syrian hamster model The authors acknowledge the support received from Prof (Dr.) Priya Abraham, The authors have declared no conflicts of interest.