While the science isn’t in a general consensus about the actual severity of experienced symptoms, there does seem to be good evidence that men generally do not have as strong of an immune system response to common flus, and that common flu vaccines are not as effective in men as they are in women.

https://www.livescience.com/61164-man-flu-real.html

Men are more likely to be hospitalized, as well as die from the common flu than women.

Current research seems to be exploring the idea that testosterone hampers immune response (antibody production) whereas estrogen promotes it.

Being dismissive of men’s less effective immune responses to common flus is about as sexist as a man similarly bellittling a woman having menstrual cramps.

https://newatlas.com/health-wellbeing/man-flu-cold-real-or-not/

The pop-cultural portrayal of men as overly weak and hysterical patients when facing a simple flu may hinder men from seeking for appropriate medical treatment because of a fear to be ridiculed. To avoid a culture of toxic masculinity, stereotypical portrayals of gender roles should be avoided."

The way you dismantle toxic masculinity is by listening to men when they describe their lived experiences, allowing them to feel comfortable and not judged when they describe their medical symptoms.

The way you reinforce toxic masculinity is by making it taboo for them to express when they are in pain, and mocking them when they aren’t acting like a big strong tough, toxically masculine guy.

EDIT: a quick overview of @chionogirl via nitter, she appears to be some kind of conservative tradwife/stay at home mom from the American South.

Their Valentines Day tweet is:

Happy Valentine’s Day to heterosexual monogamous couples only (heart emoji)

What a gem of a person.