Talk:COVID-19 vaccine side effects

Math
I have removed the erroneous claim that 10% of 2,403 younger women experienced a clinically significant delay in their next menstrual period. This is wrong according the cited source. The actual math runs like this:


 * There were 3,959 women in the study.
 * 2,403 participants were vaccinated during the study, and 1,556 were not.
 * 358 of the vaccinated group received both doses of the vaccine in the same cycle.
 * 10.6% of the 358 in this subgroup experienced a clinically significant, temporary change in cycle length.

Put another way, one out of every 63 vaccinated women (10.6% of the small subgroup, 1.58% of all vaccinated participants, 0.95% of all study participants) had both two doses during the same menstrual cycle and also a clinically significant delay in the start of the next cycle.

Also, because 4.3% of the 1,556 unvaccinated study participants also had this experience, almost half of this "vaccine side effect" was likely not related to vaccination at all.

If we need to add specific numbers, then the relevant statement is probably "Women who receive both doses of the vaccine in the same menstrual cycle have about twice the normal risk of their next period starting more than a week late". If you really feel a need for specific numbers from a single primary source, then it's "10.6% of the 358 participants who received both doses of the vaccine in the same cycle experienced a clinically significant change in cycle length" – not 10.6% of 2,403. WhatamIdoing (talk) 16:48, 27 May 2022 (UTC)