A study published in Nature Medicine about effectiveness of Covid-19 vaccines for preventing long Covid showed only a 15% preventive benefit. Was that an accurate and uncompromised assessment?

That was a reasonable finding from the data in hand, but there were some issues with skewing of the results because of uncertainty in diagnostic criteria and other complications. The general trend is accurate, that vaccination has a benefit in reducing the likelihood of long Covid symptoms developing. The way to look at this is it is consistent with other positive results rather than fixing on a number that is truly representative.