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There have been reports ad journalists questions about the severity of COVID-19 in different sexes.
Prof Philip Goulder FMedSci, Professor of Immunology in the Department of Paediatrics, University of Oxford, said:
“It is becoming increasingly recognised that there are substantial differences in the immune system between males and females and that these have significant impact on outcome from a wide range of infectious diseases. The immune response throughout life to vaccines and infections is typically more aggressive and more effective in females compared to males.
“Several factors contribute to this, but these include the fact that females have two X chromosomes compared to one in males, and a number of critical immune genes are located on the X chromosome. In particular, the protein by which viruses such as coronavirus are sensed is encoded on the X chromosome. As a result, this protein is expressed at twice the dose on many immune cells in females compared to males, and the immune response to coronavirus is therefore amplified in females.
“Apart from the immune sex differences that impact on mortality from infections such as coronavirus, there are important behavioural differences between the sexes, for example in smoking, which affect the level of pre-existing disease such as heart disease, chronic lung disease and cancer. These have a huge impact on the outcome from infections such as coronavirus. The sex differential in smoking is especially marked in some countries such as China, where 50% of men smoke compared to 5% in women.”
Dr James Gill, Locum GP & Honorary Clinical Lecturer, Warwick Medical School, said:
“Does being male impact on the severity of an individual’s COVID-19 infection?
“As with so many factors about this coronavirus pandemic, we are beginning to recognise new patterns in the data which improve our knowledge of the disease, and may reveal ways to combat the spread, or improve our treatment protocols. Currently evidence is mounting that men are experiencing more severe symptoms, and have a higher mortality rate when compared to women – one analysis from the CDC in China indicated a 1.1% increase in fatality rate in men compared to women (http://weekly.chinacdc.cn/en/article/id/e53946e2-c6c4-41e9-9a9b-fea8db1a8f51).
“The reason behind this difference in risk is currently unknown, but there are several schools of thought on the matter, from the assumption that simply men don’t look after their bodies as well, with higher levels of smoking, alcohol use, obesity and other deleterious health behaviours, through to immunological variations in genders – that women may have a more aggressive immune system, meaning a greater resilience to infections. The concept of a more aggressive female immune response may also explain why auto immune diseases, where the body attacks itself, are also more prevalent in women.
“Smoking has been considered one of the biggest contributing factors due to the damage to the cilia in the lungs, increasing the risk of any respiratory infection, not merely COVID-19. Whilst smoking is a plausible factor, globally, across various different cultures, where smoking rates do differ, we are still seeing the sustained difference in mortality between men and women. Whilst we don’t have a definitive answer on why there is a difference between how men and women respond a COVID19 infection at the immunological level – yet – currently it is a fair assumption that there will be a significant interplay between the biology and the environmental facts. Ultimately, whether male or female it is not too late to initiate lifestyle factors such as stopping smoking or increasing intake of fruit and vegetables, which may increase your chances of successfully fighting a COVID19 infection.”
All our previous output on this subject can be seen at this weblink: www.sciencemediacentre.org/tag/covid-19
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