BioAnalysis of Omicron: Zoonosis, Anthropozoonosis, or Both? Time for a Completely New Solution

This analysis is based on past experience and studies applicable to SARS-CoV-2, and the Omicron variant in particular. I still maintain that SARS-CoV-2 is an animal virus, a generalist, and opportunist with an imposed human bias. It has kept its options to infect and be maintained in animal species other than humans. Humans have just provided a profound opportunity for viral amplification and transmission with travel, global contact, disregard for sanitary precautions, socioeconomic disparity (poor vaccine distribution and preferential access to life saving treatments), and political interference (positive and negative influence). Omicron can be viewed as the natural evolutionary progression of the virus under these circumstances. Recent data has shown the first indications that Omicron is following an animal coronavirus pattern that I have described in several earlier posts. The confusion in the press and the debate amongst the scientific community over Omicron being more transmissible (clearly) and less pathogenic (awaiting more data) is an unclear relationship, if any connection at all, between pathogenicity (morbidity and mortality) and transmissibility. Transmissibility seems to follow a logical course of higher transmissibility leading to greater incidence and prevalence of a variant like Omicron, but it has its limitations. Transmissibility is not linear but asymptotic in is evolution. Too much transmissibility and vulnerable hosts become harder too find; too little and the virus infectivity dies out with distance between and immunity of hosts. An inhibition of immunity by the virus leads to greater viral production and lower infectious dose, but too much and the virus spreads throughout a host’s tissues that leads to incapacitation (limited mobility for viral spread) or lethality (eliminating a viral host for replication and spread); too much or too quick induction of immunity and not enough virus is available for transmission. These are the tensions pulling on virus mutations, governing its evolution.

Omicron has, in a preliminary study, shown a preference for infecting human upper respiratory tissue over lung tissue in culture. The omicron variant multiplies about 70 times faster inside human respiratory tract tissue than the delta variant does, according to a University of Hong Kong report (https://www.med.hku.hk/en/news/press/20211215-omicron-sars-cov-2-infection?utm_medium=social&utm_source=twitter&utm_campaign=press_release). This is supported by the fact that, in the U.S., cases caused by the Omicron variant jumped seven times in a week, from 0.4% to 2.9% total cases, according to Centers for Disease Control and Prevention estimates. The infection incidence is approaching 13% of cases in the region including New York and New Jersey. This is close to the prevalence of other coronaviruses in animal populations at any given time (10-15%). The preponderance in the upper respiratory tract (including bronchi) assures large amounts of virus will be expelled with coughs and sneezes and will most likely take hold in exposed susceptible people. Localized immunosuppression in these tissues before recovery is more than adequate to rapidly reproduce and provide time to spread the virus. No increase in pathogenicity is necessary.

However, a shift from preference for receptors deep in the lungs to those of the upper respiratory tract assuring more likely human to human transmission has been seen before in influenza. Avian influenza prefers deeper receptors in the human respiratory system and is more pathogenic. When it reassorts with other strains like those of pigs and humans, it becomes more transmissible in these species, mostly less pathogenic, but not always and without assurance of such a result. So no assurance of Omicron’s decrease in pathogenicity.

The increase in lethality of an infectious entity is often indifferent to transmissibility, especially if it is quick and a living host is not required to spread the agent. Sometimes the dead are a greater source of transmissible agent than the living and the agent is thus selected for lethality as it mutates or against attenuation that would allow recovery and elimination of the infectious form. This situation describes anthrax that is transmitted through spores that form upon death and dismemberment of the host. Even Ebola, until recently, was most likely to be transmitted from person to person by preparation of the dead for burial. Today, not just the dead and dying transmit it but also the recovered through chronic infection and sexual transmission. Its nature has changed as it has moved from being an East African sporadically occurring zoonoses to an endemic urban virus in West Africa. SAR-CoV-2, like other animal coronaviruses, is not so infectiously persistent in the environment, but rather spreads through constantly maintained susceptible populations and by acute and chronic viral shedders (in animals, mostly by the GI tract, yet to be fully demonstrated in human hosts infected with adapted coronaviruses). Time will tell if SARS-CoV-2, Omicron in particular, follows this well tread coronavirus path.

Did Omicron come out of animals? Sequences shared with coronaviruses in rats (https://media.nature.com/original/magazine-assets/d41586-022-00215-2/d41586-022-00215-2.pdf). Spreading to hamsters then back to humans (https://deliverypdf.ssrn.com/delivery.php?ID=905122026003114127079123119001002108070000006036012087096100017005026012108069005085117079006123024016028096075124024095120029035039092080082014103069087050015051047119025019073007018096068101116122057113095048023013018003005127004003074071116075102028010112004123113020012112075020103113022&EXT=pdf&INDEX=TRUE).

Isn’t it time for a totally new approach that is both specific and versatile? An approach that can be applied immediately before an emerging infectious disease goes pandemic? A means to “out evolve” a virus or antibiotic resistant bacteria or other microbe before it escapes its origin ? Yes, Nanobes . “I’ve seen things you people wouldn’t believe….all those moments lost in time like tears in the rain”.