History of Genetic Engineering Advances Prior to COIVD-19 Pandemic (preprint)

Due to the fact that to date, the question of the origin of SARS-CoV-2 has not been resolved yet, the author analyzed the main advances in the development of genetic engineering of viruses that took place before the onset of the COVID-19 pandemic. The first artificial genetically modified viruses could appear in nature in the mid-1950s. The technique of nucleic acid hybridization was developed by the end-1960s. In the late 1970s, a method called the "reverse genetics" emerged to synthesize RNA and DNA molecules. In the early 1980-s, it became possible to combine the genes of different viruses and insert the genes of one virus into the genome of another virus. Since that time, the production of vector vaccines began. Currently, by modern technologies one can assemble any virus based on the nucleotide sequence available in the virus database or designed by a computer as a virtual model.Scientists around the world are invited to answer the call of Neil Harrison and Jeffrey Sachs of Columbia University, for a thorough and independent investigation into the origin of SARS-CoV-2. Only a full understanding of the origin of the new virus can minimize the likelihood of a similar pandemic in the future.

Experimental Transmission Studies of SARS-CoV-2 in Fruit Bats, Ferrets, Pigs and Chickens (preprint)

Background: A novel zoonotic SARS-related coronavirus emerged in China at the end of 2019. The novel SARS-CoV-2 became pandemic within weeks and the number of human infections and severe cases is increasing. The role of potential animal hosts is still understudied.Methods: We intranasally inoculated fruit bats (Rousettus aegyptiacus; n=9), ferrets (n=9), pigs (n=9) and chickens (n=17) with 105 TCID50 of a SARS-CoV-2 isolate per animal. Animals were monitored clinically and for virus shedding. Direct contact animals (n=3) were included. Animals were humanely sacrificed for virological and immune-pathohistological analysis at different time points.Findings: Under these settings, pigs and chickens were not susceptible to SARS-CoV-2. All swabs as well as organ samples and contact animals remained negative for viral RNA, and none of the animals seroconverted. Rousettus aegyptiacus fruit bats experienced a transient infection, with virus detectable by RT-qPCR, immunohistochemistry (IHC) and in situ hybridization (ISH) in the nasal cavity, associated with rhinitis. Viral RNA was also identified in the trachea, lung and lung associated lymphatic tissue. One of three contact bats became infected. More efficient virus replication but no clinical signs were observed in ferrets with transmission to all direct contact animals. Prominent viral RNA loads of up to 104 viral genome copies/ml were detected in the upper respiratory tract. Mild rhinitis was associated with viral antigen detection in the respiratory and olfactory epithelium. Both fruit bats and ferrets developed SARS-CoV-2 reactive antibodies reaching neutralizing titers of up to 1:1024.Interpretation: Pigs and chickens could not be infected intranasally by SARS-CoV-2, whereas fruit bats showed characteristics of a reservoir host. Virus replication in ferrets resembled a subclinical human infection with efficient spread. These animals might serve as a useful model for further studies e.g. testing vaccines or antivirals.Funding Statement: Intramural funding of the German Federal Ministry of Food and Agriculture provided to the Friedrich-Loeffler-Institut.Declaration of Interests: All authors declare no competing interest.Ethics Approval Statement: The animal experiments were evaluated and approved by the ethics committee of the State Office of Agriculture, Food safety, and Fishery in Mecklenburg – Western Pomerania (LALLF M-V: LVL MV/TSD/7221.3-2-010/18-12). All procedures were carried out in approved biosafety level 3 (BSL3) facilities.