In light of current evidence,
to what extent do you agree that
mass vaccination with leaky Covid-19 vaccines in the midst of the pandemic
will breed highly infectious variants,
as argued on www.geertvandenbossche.org and particularly this open letter ?

In the case of Covid Vaccines we are experiencing, for the first time, large-scale use of vaccines with high potential to stimulate cellular responses (as in mRNA technologies). This will improve the populational immunological shield even for other diseases by cross-reactive events. Considering the examples where the vaccination reaches high numbers, we can clearly see its beneficial effect. To date, the more important way to avoid variants is to diminish the number of infected people.

Transmission within previously exposed populations (through vaccination or infection) allows natural selection to work. But I dont see this as a problem because the vaccines reduce fatality and severe disease. SARS-CoV-2 will be endemic and it is inevitable that there will be immune driven seleciton that results in antigenically different viruses.

I think it is too late to arise this question or even think about it; it should be before start of the vaccination worldwide and depend only on the virus-induced immunity along with herd immunity. However, now vaccination is the best way to protect the population from this serious disease. I would rather say it is the time to speed up the process for mass vaccination around the globe especially developing countries. COVID-19 is like a fire, if you want to make it down from boundaries, it will take long time and spread until you can control. While, if you have a fire blanket and put over one time, it will go down quickly without any damage around. Fire blanket is the mass vaccination and we have too many examples starting from polio, measles, influenza, etc… Finally, it is very important to find suitable, effective, safe vaccine with more trials and proper time for evaluation

Widespread viral replication with incomplete immunity either because of partial immunity or a poor match for circulating variant is exactly the recipe for developing resistant variants.

LIKELY BUT NOT SURE OF SIGNIFICANCE

Vaccination is common for influenza viruses, the vaccine strains are required to update annually since the viruses evolve regularly. There is lack of information regarding vaccination will breed highly infectious influenza viruses. The SARS-CoV-2 is more likely to resemble influenza viruses, I cannot agree the statement.

With or without vaccination variants will arise. Robust vaccine-induced immunity will reduce virus transmission and minimize the emergence of variants including variants. The advancement we have made in vaccinology, will facilitate the development of vaccines against variants of concern. Vaccination is all about risk and benefit, for SARS-CoV-2, the benefit outweight the risk.

I have been studying and lecturing on vertebrate innate immunity for many years. I cannot agree with Dr. VanDen Bossche's hypothesis that acquisition of specific immunity through vaccination will suppress the innate immune response upon exposure to the same or a mutated pathogen.

No eviodence for such an effect with influenza, or with SARS-CoV-2 thus far. The Marek's disease example is irrelevent to COVID-19

Greatest driver of new variants is high transmission rates. If all other things were equal, then partial immunity can help select for variants, as we argued in Grenfell et al 2003 (Science - phylodynamics paper) - but all other things are not equal. It is clearly better to vaccinate to reduce transmission AND disease.

I did not see any evidence where leaky vaccine of COVID-19 is causing highly infectious variants.

So I think the answers provided are a bit biased because of the graph showing the results of those responding. The vaccine will not 'breed' a highly infectious variant but it may result in 'leaking' and slower spread of an infectious variant.

This has all the features of crank pseudoscience.

The SARS-CoV-2 virus is a respiratory virus. There are four other coronavirus strains that circulate in humans and there is no vaccine for them, but the lack of a vaccine is not because it would cause highly infectious variants, but because they are not that deadly. On the other hand, we have a vaccine for influenza that is typically at best about 50% effective against disease. That likely means it is 'leaky' in the same way that Dr. Vanden Bossche is thinking about it. Yet no one is arguing against the influenza vaccine. The virus is infecting millions of people everyday, and like nearly every virus it is rapidly mutating. I am certain that when all the sequences collected are analyzed, we will see that around the world nearly every amino acid substitution in the spike protein will have been seen. An imperfect vaccine will not accelerate this evolution, rather it will accelerate the whittling down of selected variants to ones that can eventually escape immune pressure. However, with fewer infected individuals this will likely actually take more time. There will be no development of a 'monster' variant that takes us back to square one. The scientists proclaiming this are just looking for attention. There is no historical analogue for such panic. Will variants emerge that are can evade immunity, with certainty, will they be 100% novel such that no one has immunity - the answer is no. Dr. VanDen Bossche should read the theories of evolution of virulence - I think he is just stuck with a myopic lab view of the world where it is possible to engineer 'monster' viruses. But in the messy real world, where the virus must contend with transmission and competition with other strains as well as other viruses. these apocalyptic scenarios are outlandish and absurd. There will be continual antigenic drift that will allow the virus to reinfect over time, and the only question is will this result in a situation like flu, where the virus causes enough severe cases each year that there is a need to regularly re-vaccinate or will this evolve to be more like regular coronaviruses which cause some cases each year and regular vaccination is probably not worth it.

The concern about selection of victim-escape mutants providing massive vaccination while the virus is spreading is easily understandable. However, current evidence is clear about the individual and public health benefits of these vaccines: drastic drop in hospitalizations/deaths as well as in new diagnosis. My guess is that if a monster should have had the opportunity to emerge, already it would have do it. Since there is no evidence for that, my interpretation is that the fitness cost in terms of viral replication to produce a new 'monster' variant might position the virus in a closed corridor: no way to escape antibody-mediated immunity and transmit efficiently, both at the same time. Since there are no efficient antivirals against SARS-CoV-2 to block infections, rapid vaccine scale up globally seems to be the best way control the pandemic. In parallel, close monitoring of selection of new variants must be ensured and new updated versions of vaccines should be produced periodically.

Vaccines only help in curtailing the infection and also the transmission.

Contrary to some of the messages here, this mechanism has been proven to take place with other viral pathogens and vaccines that do not prevent transmission can create conditions that promote the emergence of pathogen strains that cause more severe disease in unvaccinated hosts: Imperfect Vaccination Can Enhance the Transmission of Highly Virulent Pathogens https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002198

It is the widespread virus among populations that breed highly infectious variants. Vaccines are the best ways to prevent viral infection. The NK cell part does not make sense.

According to recent data (14 days average) the infection rate is down by 37 % in US, while mortality rate is down by only 5 %. Conclusion: the current Covid-19 vaccines are showing NO EFFICACY against circulating mutant strains of the virus. Even months after phase 3 clinical trials, there are NO ANY solid data showing that the current vaccines are capable of reducing the mortality. We have 98 % of natural protection against natural infection (about 2 % of mortality) and, if the vaccines are not able to reduce this 2 % and are NOT resulting in sterile protection, which is obvious, then the vaccination even 3-4 times a year (even with vaccines bearing mutant S proteins) will not be beneficial at all. More accelerated appearance of more pathogenic variants as a result of vaccine-induced immune pressure with potentially catastrophic consequences is possible scenario.

I believe that an outgrowth of highly infectious or virulent SARS-CoV-2 variants has nothing to do with any vaccination strategy, though leaky vaccinations happening in the midst of an outbreak may possibly result in some immune-escape variants being selected for

The vaccines are not particularly leaky. Vaccination, like infection, can theoretically promote the selection of antigenic variants but these might not be particulaty fit in a naive population, but might have acquired the ability to spread in an immune population. The current evidence does not seem to link increased transmission with vaccination (e.g. the alpha varinat arose prior to vaccination); the delta variant emerged in an area without a large degree of vaccination (but infection might be a different matter). Vaccination is still the best way to protect the population from this serious disease.

I don't understand Dr. VanDen Bosshe's logic. Further, antibiotics are not antibodies. Comparisons are not warranted. Comparison with extant vaccine's to Covid vaccines is warranted and not done. There are no examples of viral 'escape' to measles, mumps, rubella, and polio vaccines. There is no immunologic basis for the opinions expressed by Dr. VanDen Bosshe.