[mactournier]

Contrary to the HN title, the paper is not about causal inference, it is a case-control study. A good primer on the limitations of case-control studies can be found here: https://www.medicalnewstoday.com/articles/280936#limitations

[letmevoteplease]

The abstract of the study states, "These findings cannot be explained by any known risk factor for MS and suggest EBV as the leading cause of MS."

[axlee]

Your contrarian approach is detrimental to proper research. Authors have found a very strong link that cannot be explained by any other risk factors. What risk factors are you suggesting they should look into?