Women face 22% higher odds of developing long COVID than men do - and they suffer different symptoms.
That's according to a new study, one of the very few to compare long COVID symptoms by sex using data collected from 1.4 million patients.
Long COVID is a syndrome defined by complications that persist for more than four weeks after the initial infection, and sometimes for many months and even years.
Researchers at Johnson & Johnson's Office of the Chief Medical Officer women's health team found that men and women suffer different long COVID symptoms.
Women experience a variety of symptoms including ear, nose and throat issues; mood, neurological, skin, gastrointestinal and rheumatological disorders; and fatigue.
Male patients are more likely to experience endocrine symptoms such as diabetes and kidney disorders.
The researchers write: "Knowledge about fundamental sex differences underpinning the clinical manifestations, disease progression, and health outcomes of COVID-19 is crucial for the identification and rational design of effective therapies and public health interventions that are inclusive of and sensitive to the potential differential treatment needs of both sexes.
"Differences in immune system function between females and males could be an important driver of sex differences in long COVID syndrome.
"Females mount more rapid and robust innate and adaptive immune responses, which can protect them from initial infection and severity. However, this same difference can render females more vulnerable to prolonged autoimmune-related diseases."
Researchers reviewed 640,634 scientific studies relating to 1,393,355 individuals – of these, only 35 studies had separate data for men and women. Very few studies broke down the symptoms of COVID by sex, although many examined sex differences in hospitalisation, ICU admission, ventilation support and mortality.
Read more: Long COVID - what are the symptoms?
The researchers write: "Sex differences in outcomes have been reported during previous coronavirus outbreaks.
"Therefore, differences in outcomes between females and males infected with SARS-CoV-2 could have been anticipated.
"Unfortunately, most studies did not evaluate or report granular data by sex, which limited sex-specific clinical insights that may be impacting treatment."
Watch: Two million estimated to be suffering from long COVID in UK