Sex needs to be taken into account in research on COVID-19; also, we “recognize” that sex is not fixed.

Well if sex is not fixed, how can it be taken into account in research on COVID-19? How can you take it into account if you think you can’t know who is which sex?

Men this, women that – but, by the way, we don’t actually know which subjects were men and which were women. But here are our findings anyway. But! But! We recognize that we don’t actually know which subjects were men and which were women.