Thread by @StabellBenn

The statements put forward by @GVDBossche have created anxiety. @GVDBossche has invited to discussion, but few scientists seem to have replied. The lack of response seems to generate more anxiety. I have received many requests to give my take and felt obliged to do so. 1/n

First a few words on my background: I am an MD working in epidemiology/global health>27 years. Our studies show non-specific effects of vaccines on other infections #NSEvac; I therefore also did immunological vaccine studies to understand mechanisms. 2/n thelancet.com/journals/lanin…

My main interest in COVID-19 vaccines is whether these new vaccines also have #NSEvac (So far none of them have been studied for their effect on other infections). Thus, vaccine immunology is not my main area, but I do know more than most. Hence my feeling of obligation. 3/n

I have now studied the material put forward by @GVDBossche. Let me start with points of agreement. I agree with him that the innate immune system plays an important role and vaccines that are targeting the innate immune system may be crucial... 4/n

We and others are currently testing some candidates in the form of well-known live attenuated vaccines with stimulating effects on the innate immune system; BCG vaccine, oral polio vaccine and MMR vaccine. 5/n science.sciencemag.org/content/368/64…

I also agree that it could be a concern that “Stringent and widespread infection prevention measures are now increasingly compromising their innate immunity and rendering them more susceptible to symptomatic infection”. 6/n

https://twitter.com/lindy2350/status/1365300702860476422?s=20

Now to what I don't understand. @GVDBossche argues that after asymptomatic infection, people have "used up" their natural antibody, making them prone to reinfection. How used up? Normally the immune system is good at making more of what is being useful. 7/n

@GVDBossche further argues that after asymptomatic infection, people only have short-lived measurable specific antibodies of suboptimal maturity. But e.g. in Guinea-Bissau most cases were asymptomatic, but still IgG positives months after. 8/n medrxiv.org/content/10.110…

I would expect that they would respond anamnestically next time and this would protect, at least from severe disease. The fact that we have not seen a high rate of rapid reinfections one year into the pandemic supports that. 9/n linkinghub.elsevier.com/retrieve/pii/S…

Generally, @GVDBossche don't seem to count in immunity after natural infection. Most people develop good immunity, including T-cell immunity towards non-spike epitopes, i.e. presumably also towards vaccine escapes. They contribute to herd immunity.10/n pubmed.ncbi.nlm.nih.gov/33128877/

A cornerstone in the argument seems to be that an adaptive immune response weakens the innate immune response. It wouldn't be logical nor do I think we have such evidence. On the contrary many infections and vaccines train the innate immune system. 11/n nature.com/articles/s4157…

Reg. vaccines: @GVDBossche says that getting infected while having a suboptimal response after a first dose of vaccine will lead to escape mutants. Not my area, but most people argue that due to the strong protection already after first doses, this is unlikely. 12/n

@GVDBossche argues that with mass vaccination of the elderly, the more the virus "will be forced to continue causing disease in younger age groups". Also not understood. There is no fixed quota of disease; presumably the less disease - the less opportunities to get infected. 13/n

From a historical perspective, pandemics have not all been mild in children/young people and worse with increasing age (e.g. Spanish flu, swine flu). Hence, the theory that young people have more natural antibody and that protects them against disease does not seem to hold. 14/n

Bottomline: I agree with @GVDBossche that innate immunity is important, and I'm also cautious about the new vaccines (as we still don't know about their #NSEvac). But I don't follow the argument that the vaccines will breed highly infectious variants and worsen the pandemic. 15/n

PS: I have a feeling I will regret posting this thread; the debate so far has mostly been non-scientific and nasty. However, I feel responsible towards lay people who are truly concerned about the doomsday scenario and request a scientist response. Please treat me nicely🙂