Uh...the burden is on those who advocate Ivermectin to prove it COULD work- not on those who don't advocate it to prove it doesn't. And there is no good reason to refuse to vaccinate solely in the name of an ideology, or solely out out a pointless obsession with denying credit to any particular politician.
Besides. it's an inherent contradiction to insist that Trump get credit for the vaccine AND refuse to be vaccinated.