[fdewrewrewf]

>The researchers analyzed data on at least three consecutive cycles before vaccination and at least one cycle after.

>After vaccination, cycle length had increased by only .02 days for individuals who received one dose per cycle, and .85 days for individuals who received two doses in one cycle, compared to participants who were not vaccinated.

I don't know how this conclusion has any weight, given the tiny time-scales of the data analysed. Was this data picked from the same period of time across all participants? Otherwise, you could just pick any 4 weeks from each participant and weight the result any way you wanted.