EBV reactivation was already studied as increasing the risk for long Covid [0]. But since 90% (at least) of the population has these antibodies and the latent

EBV reactivation was already studied as increasing the risk for long Covid [0]. But since 90% (at least) of the population has these antibodies and the latent virus, it's very hard to devise a study. The remaining 10% have almost certainly had the virus but have no antibodies detectible by the screening method. That means an unsound screening method is as good a predictor of MS risk as throwing dice. [0] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8233978/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8233978/