Covid-19 and China, a lot of food for thought
Dear Editor,
Following the draconian measures put in place by Chinese health authorities throughout the SARS-CoV-2 pandemic, a totally relaxed approach has been recently adopted in order to stop the people's angry protests against China's "zero Covid" strategy. This has resulted, in turn, in a dramatic surge of Covid-19-associated/related hospitalizations and deaths especially among elderly patients, due to the low level of anti-SARS-CoV-2 people's immunization with vaccines less effective than those based upon the mRNA technology.
During the first three years of the pandemic, we have gained crucial knowledge about the complex viral-(human and animal) host interaction dynamics. Noteworthy, the acquirement of "non-silent" mutations in the SARS-CoV-2 genome, consisting of approximately 30,000 nucleobases, appears to be tightly connected with viral multiplication kinetics, with each replication cycle implying as an an average the occurrence of one mutational event every 10,000 nucleotides (Di Guardo, 2022a).
This clearly justifies the appearance, in the course of the pandemic, of pathogenic "variants of concern" (VOIs) like "alfa", "beta", "gamma" and, overall, "delta", or highly transmissible and immune-evasive VOIs like "omicron" and its numerous subvariants, including the recently/newly emerged "Centaurus", "Chiron", "Gryphon" and "Cerberus".
Based upon the above, the emergence of additional, highly pathogenic and/or contagious SARS-CoV-2 VOIs, capable of bypassing the immunity conferred either by vaccination or previous infection, is a matter of concern in the current China's epidemiologic scenario. Still of interest, while SARS-CoV-2 - in a similar fashion to the vast majority of the pathogens causing "emerging infectious diseases" - most likely originated from an animal (Rinolophus spp. bat) source, with the possible intervention of an "intermediate" host, at least thirty domestic and wild animal species have been hitherto deemed susceptible to SARS-CoV-2 infection, either spontaneously or experimentally. Furthermore, beside acquiring the virus from infected human hosts, intensely reared mink from Denmark and The Netherlands, along with white-tailed deer (Odocoileus virginianus) from Ontario (Canada), were also able to "return" the virus in a mutated form ("cluster 5" and "B.1.641", respectively) to mankind (Di Guardo, 2022b).
These are very important lessons that we have learned throughout the dramatic Covid-19 pandemic, which has thus far killed almost 7 million people worldwide, according to the official data released by the World Health Organization.
And, "sic stantibus rebus" in China, the "history could repeat itself", considering the "global village" we all live in!
As a concluding remark, a holistic, multidisciplinary and scientific evidence-based approach, permanently inspired by the "One Health" principle, is what we need in order to adequately cope with this as well as with all the forthcoming epidemics and pandemics, while firmly keeping in mind that human, animal and environmental health are tightly and reciprocally linked to each other.
References
1) Di Guardo, G. (2022a). Is Gain of Function a Reliable Tool for Establishing Sars-Cov-2 Origin?. Advances in Microbiology, 12, 103-108. doi: 10.4236/aim.2022.123009.
2) Di Guardo, G. (2022b). SARS-CoV-2 Susceptibility of Domestic Animals and Wildlife in the Media Narrative. Pathogens 11, 1356. https://doi.org/10.3390/pathogens11111356.