New data reveals significant differences between how the sexes respond to COVID-19
Infection with the novel coronavirus, which causes the deadly COVID-19 illness and the associated mortality rates, has much to do with sex differences and gender. Sex differences are the biological characteristics we associate with the sex that one is assigned at birth, while gender is commonly understood as the ensemble of social expectations, norms, and roles we associate with being a man, woman, trans- or nonbinary person – the pandemic has regardless negatively affected all.
Recently, the Global Health 5050 organisation, which promotes gender equality in healthcare, has collected relevant available data from countries with the highest numbers of confirmed COVID-19 cases and revealed that men are more than twice as likely to die from the disease.
According to the organisation, the highest ratios of male to female COVID-19 deaths are seen in Denmark and Greece at 2.1 to 1. In these countries, men are more than twice as likely to die from COVID-19 as women. In Denmark, 5.7% of the total number of cases confirmed among men have resulted in death, whereas 2.7% of women with confirmed COVID-19 have died. In Norway (1.2 to 1), these numbers stand at 1.3% of the men and 1.1% of women; in Iran (1.1 to 1), at 5.9% compared with 5.4%, respectively; and in China (1.7 to 1) at 4.7% compared with 2.8%.
Why the new coronavirus seems to cause more severe illness in men boils down to biological sex differences, such as sex chromosomes and sex hormones that influence how a person’s immunity responds to a pathogen.
A woman’s innate immune response is apparently able to “mount a more vigorous immune response” to infections and vaccinations – past studies mention that the hormone estrogen may have a protective role. Estrogen suppresses the escalation phase of the immune response that leads to increased cytokine release; cytokines are responsible for tissue damage within the lungs and leakage from pulmonary blood vessels and is characteristic for more severe symptoms of COVID-19.
Some researchers have also observed that lifestyle factors, such as smoking and alcohol consumption, which tend to occur more among men, can also be a factor to the overall higher mortality rates among men.
Unfortunately, there is not enough data available to draw a conclusion about infection rates by sex. However, it is worth noting that in some countries, including South Korea and Spain, more women have contracted the virus than men. Gendered norms in the health workforce – where women represent the majority, according to the World Health Organization (WHO) – and as humble caregivers could easily mean expose women to the virus and could explain the higher infection rates in some of these countries.
It is said that “recognising the extent to which disease outbreaks affect women and men differently is a fundamental step to understanding the primary and secondary effects of a health emergency on different individuals and communities, and for creating effective, equitable policies and interventions,” e.g. devising policies or intervention strategies that consider the needs of women who work as frontline healthcare workers could help prevent the higher infection rates among women.
In addition, as men and women tend to react differently to potential vaccines and treatments, identifying the key difference in both their immune responses is crucial to safe clinical trials and effective and suitable drugs against the virus.