Is there actually any evidence of this?
Back to this question; I haven't had a reply to my email yet, but I had some thoughts.
The reason he has concluded that antigen-specific antibodies can suppress innate antibodies from binding to covid-19, seems to be related to the observation that during the first phase of the pandemic, children were always asymptomatic when infected, but when infected later on they developed symptoms and illness.
Children were not symptomatic early on because they have high levels of natural antibodies. Because these can recognize a wide range of pathogens they are able to bind to covid-19.
Because they had no previous exposure to Covid-19, they hadn't yet made antigen-specific antibodies. But upon first exposure they did then mount a suboptimal antibody response, and these antibodies would be gone within 2 months, as occurs after a first vaccination.
Some children would be re-exposed to the virus while they had these suboptimal antibodies. At this point the children developed symptoms and illness. He says that the reason for this must be that the higher strength of binding of the antigen-specific antibodies enabled them to bind better than the less specific innate antibodies could do.
While suppressing the innate antibodies, the antigen-specific antibodies, being of low quality and quantity, failed to neutralize the virus and thus allowed it to bind to ACE2 and infect host cells, so that these children developed symptomatic illness.
We do have evidence that suboptimal antibodies can bind to a virus but not neutralize it. They are called 'non-neutralizing antibodies'.