Q&A #24 : Are other bat coronaviruses posing a threat to human health, even to the extent that new vaccines ought to be developed?

Question:

Are other bat coronaviruses posing a threat to human health, even to the extent that new vaccines ought to be developed as recently suggested in: https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1010828?

Answer:

This is yet another example of great scientists drawing the wrong conclusions. It is completely distracting us from the real issue, which is the increasing resistance of the ever-evolving circulating Omicron subvariants to all potentially neutralizing antibodies (Abs) in vaccinees no longer showing overt symptoms of C-19 disease. This unprecedented phenomenon will soon put tremendous pressure on the virulence-inhibiting activity of the infection-enhancing antibodies. Unless I am stupid, this is now rapidly paving the way for a global health disaster as always predicted.

What is the conclusion of these authors and why are they so wrong in advocating for new vaccines?

They conclude: ‘Critically, our findings highlight the urgent need to continue development of new, and broader-protecting sarbecovirus vaccines’ or: ‘Taken together, these results demonstrate that new recombinant sarbecoviruses may pose a threat to current SARS-CoV-2 vaccines.’

Questions should never be addressed at whether findings pose a threat to a vaccine but rather whether they pose a threat to (global) health! It is not because a virus can enter human cells and is resistant to Abs elicited against a heterologous spike (S) protein (originating from C-19 vaccines!) that it poses a threat to human health! What about viral virulence and the capacity of those bat coronaviruses to subvert the human innate immune system? If that capacity is low, then the human innate immune system will take care of it, just like it does in the bat! And even if the innate immune system would not achieve full viral clearance, it is highly unlikely that the remaining virus-infected cells or viral particles would not be removed in due time by MHC-unrestricted cytotoxic lymphocytes (CTLs) or newly induced Abs, respectively (unless the virus is highly infectious and invariably causes symptomatic infection!). In that regard, it is interesting to cite the authors’ own words : ‘the Khosta bat sarbecoviruses are genetically distinct from human SARS-CoVs in that they lack genetic information encoding for some of the genes thought to antagonize the immune system and contribute to pathogenicity, such as Orf8’. Well, Orf8 is known to primarily affect the host’s innate immune defense https://www.frontiersin.org/articles/10.3389/fgene.2021.693227/full).

It is so wrong when scientists jump to conclusions that are merely based on their insights into a single scientific discipline (in this case, virology). Furthermore, it is highly likely that even vaccinees would be protected against the Khosta coronaviruses as they are now increasingly contracting breakthrough infections caused by new Omicron variants. The very authors of this publication are reporting data showing enhanced neutralization capacity in sera from vaccinees experiencing a vaccine breakthrough infection caused by the first reported Omicron variant (B.1.1.529).  However, vaccine breakthrough infections caused by less distant Omicron subvariants (e.g., BA.2-derived) have been shown to elicit much broader cross-neutralizing capacity directed at more conserved S protein-associated domains (https://pubmed.ncbi.nlm.nih.gov/36125366/).

Hence, trained innate immunity in the unvaccinated and more frequent breakthrough infections by less distant Omicron subvariants (e.g., BA.2- or BA.4/5-derived) in vaccinees almost certainly obviate the need for any global health concern related to new coronaviruses that zealous researchers may (continue to) detect in bats. Potential public/ global health concerns should never be based on virological or epidemiological findings only! Based upon the immunological considerations explained above, there is indeed no reason to believe that productive spill-over of bat coronaviruses or other animal coronaviruses to the human species cannot be controlled by natural immunity and ultimately be tamed by herd immunity as happened with other coronaviruses (i.e., common human coronaviruses, including types 229E, NL63, OC43, and HKU1) that primarily cause asymptomatic or mild to moderate infections in the human population . The C-19 mass vaccination program has clearly illustrated that vaccination does not work in an environment where the virus rapidly spreads and merely promotes natural selection and expansion in prevalence of viral variants that escape potentially neutralizing vaccine-induced Abs. No vaccine technology is currently capable of competing with the type of protective immunity that a pandemic confers to the population. The resulting herd immunity is typically broadly protective and sterilizing and therefore dramatically reduces viral transmission. No single vaccine can provide protective population immunity when used during a pandemic. Mass vaccination campaigns result in a type of population immunity that has exactly the opposite effect in that they promote viral transmission by virtue of natural selection of more infectious immune escape variants. As trained innate immunity is a cornerstone of herd immunity, all efforts to protect the population should focus on enabling herd immunity in ways that keep hospitalization and morbidity rates as low as possible. Vaccines will ultimately have the opposite effect whereas strengthening the population’s innate immune system (via healthy lifestyle) while avoiding overcrowding combined with early outpatient treatment of  those with a weakened innate immune system (e.g., the elderly and those with underlying disease) are the holy grail for effectively and rapidly driving the virus into endemicity and minimizing the toll on human lives.

Last, it is interesting how the peer-reviewed literature continues to deny the impact of the C-19 mass vaccination program on SARS-CoV-2 immune escape. The authors of this paper seem to have found an elegant way to escape censorship by phrase the threat of immune escape as follows: ‘As individuals receive additional SARS-CoV-2 vaccine boosters and SARS-CoV-2 continues to circulate, new viral variants emerge that can alter and broaden the immune response to sarbecoviruses’!