As COVID-19 is spreading to every corner of the globe, it seems like this virus affect people differently. Apart from the statistic that older people are at higher risk for severe illness, scientists also found out that male is a risk factor for morbidity.
According to the report from Italy and The Chinese Centers for Disease Control and Prevention (CDC), men are experiencing more severe disease than women in almost every age range. CDC reviewed 44,672 cases and found that 2.8 percent of infected men died, while the disease proved fatal in only 1.7 percent of women. The trend follows previous outbreaks, including the 2003 SARS pandemic and the 1918 Spanish flu pandemic.
One possible biological cause of the trend is that men are not as good at mounting an immune response as women, which means they would suffer more severe disease as the virus takes hold. Sabra Klein, researcher who studies sex differences in viral infections at the Johns Hopkins Bloomberg School of Public Health, explained that, “This is a pattern we’ve seen with many viral infections of the respiratory tract – men can have worse outcomes. We’ve seen this with other viruses. Women fight them off better.”
Although, the exact cause for this difference is unknown, scientists believed that sex hormone Estrogen, which is abundant in women, tends to plays a key role in immunity. They also believe that there are also lots of immune-related genes coded for on the X chromosome, of which women have two while men only have one.
Another hypothesis is that lifestyle could also play an integral role. Smoking, in particular, is known to exacerbate a host of respiratory diseases. According to a study published on NCBI, there are around 316 million adult smokers in China which is the largest smoking population in the world, and around 52.1 percent of all men in China are smokers compared to just 2.7 percent of women. This presents a question for further investigation on ‘how gender and smoking are linked to COVID-19 morbidity?’
In addition, statistic shows that more men suffer from hypertension than women, which is another mechanism which COVID-19 could prove more fatal for men. The CDC also states that cardiovascular disease is the leading cause of death for men, and a recent study has found that two medications used to treat different types of cardiovascular disease, ACE inhibitors and angiotensin receptor blockers, make it easier for the virus to attack the lungs. So, they may be at increased risk of severe disease outcomes.