If Ivermectin binds to spike p. as says in the document, then this is huge in more understanding of how it helps covid. So the vacc prevents virus from entering cell by having immune system detect it and squash it, along with adding the risk of having the body make spike protein.
Now we have IVM binding to spike p. from virus and thus potentially neutralize the virus. Thus it would seem that you would want to have a good concentration of IVM circulating in the body at time of infection.
The mechanism of action here does not produce the side effect and risk of the vacc.