Protection against reinfection with D614- or G614-SARS-CoV-2 isolates in golden Syrian hamster

Abstract

Reinfections with SARS-CoV-2 have already been documented in humans, although its real incidence is currently unknown. Besides having a great impact on public health, this phenomenon raises the question of immunity generated by a single infection is sufficient to provide sterilizing/protective immunity to a subsequent SARS-CoV-2 re-exposure. The Golden Syrian hamster is a manageable animal model to explore immunological mechanisms able to counteract COVID-19, as it recapitulates pathological aspects of mild to moderately affected patients. Here, we report that SARS-CoV-2-inoculated hamsters resolve infection in the upper and lower respiratory tracts within seven days upon inoculation with the Cat01 (G614) SARS-CoV-2 isolate. Three weeks after the primary challenge, and despite high titres of neutralizing antibodies, half of the animals were susceptible to reinfection by both identical (Cat01, G614) and variant (WA/1, D614) SARS-CoV-2 isolates. However, upon re-inoculation, only nasal tissues were transiently infected with much lower viral replication than those observed after the first inoculation. These data indicate that a primary SARS-CoV-2 infection is not sufficient to elicit a sterilizing immunity in hamster models but protects against lung disease.

Monitoring Natural SARS-CoV-2 Infection in Lions (Panthera leo) at the Barcelona Zoo: Viral Dynamics and Host Responses

“…Vero E6 cells (ATCC ® repository, CRL-1586™) and SARS-CoV-2 stocks (passage 3; hCoV-19/Spain/CT-2020030095/2020; GISAID ID EPI_ISL_510689) were prepared as previously reported in [ 20 , 21 ] in Dulbecco’s modified Eagle Medium, DMEM (Lonza, Basel, Switzerland) supplemented with 5% fetal calf serum (FCS; EuroClone, Milan, Italy), 100 U/mL penicillin, 100 μg/mL streptomycin, and 2 mM glutamine (all from Gibco Life Technologies, Madrid, Spain).…”

“…Nasal and fecal swabs positive for SARS-CoV-2 as determined by RT-qPCR were evaluated for the presence of the infectious virus by titration in Vero E6 cells, as previously reported [ 21 , 28 ]. Direct samples and ten-fold dilutions were transferred to Vero E6 monolayers.…”

“…The seroneutralization assay using replicating SARS-CoV-2 was performed as previously described [ 21 , 29 ]. Serum samples were inactivated for 30 min at 56 °C.…”

“…The seroneutralization assay using replicating SARS-CoV-2 was performed as previously described [21,29]. Serum samples were inactivated for 30 min at 56 • C. Then, sera were first diluted 1:50 and then were 3-fold serially diluted in supplemented DMEM, mixed 1:1 with the SARS-CoV-2 isolate (EPI_ISL_418268), and incubated 1 h at 37 • C. Then, each dilution mixture (in duplicates) was transferred to Vero E6 monolayers containing 100 TCID50 of SARS-CoV-2 per well and were cultured for 3 days at 37 • C and 5% CO 2 .…”

SARS-CoV-2 B.1.351 (beta) variant shows enhanced infectivity in K18-hACE2 transgenic mice and expanded tropism to wildtype mice compared to B.1 variant

“…The copyright holder for this preprint this version posted August 3, 2021. ; https://doi.org/10.1101/2021.08.03.454861 doi: bioRxiv preprint replication and viral pneumonia is detected, but eventually resolved by the action of the immune response (Brustolin et al, 2021), and could open the door to develop better SARS-CoV-2 models than transgenic hACE2 mice. This, however, also raises concerns on how new variants with increased affinity to ACE2 could expand their host tropism to animal species that were non-susceptible to earlier SARS-CoV-2 variants, potentially generating new zoonotic reservoirs and increasing the risk of new spillover and spread of new variants in humans.…”