The coronavirus that originated in China has spread fear and anxiety around the world. But while the novel virus has largely spared one vulnerable group — children — it appears to pose a particular threat to middle-aged and older adults, particularly men.
This week, the Chinese Center for Disease Control and Prevention published the largest analysis of coronavirus cases to date. Although men and women have been infected in roughly equal numbers, researchers found, the death rate among men was 2.8%, compared with 1.7% among women.
Men also were disproportionately affected during the SARS and MERS outbreaks, which were caused by coronaviruses. More women than men were infected by SARS in Hong Kong in 2003, but the death rate among men was 50% higher, according to a study published in the Annals of Internal Medicine.
Some 32% of men infected with Middle East respiratory syndrome died, compared with 25.8% of women. Young adult men also died at higher rates than female peers during the influenza epidemic of 1918.
A number of factors may be working against men in the current epidemic, scientists say, including some that are biological, and some that are rooted in lifestyle.
When it comes to mounting an immune response against infections, men are the weaker sex.
“This is a pattern we’ve seen with many viral infections of the respiratory tract — men can have worse outcomes,” said Sabra Klein, a scientist who studies sex differences in viral infections and vaccination responses at the Johns Hopkins Bloomberg School of Public Health.
“We’ve seen this with other viruses. Women fight them off better,” she added.
Women also produce stronger immune responses after vaccinations, and have enhanced memory immune responses, which protect adults from pathogens they were exposed to as children.
“There’s something about the immune system in females that is more exuberant,” said Dr. Janine Clayton, director of the Office of Research on Women’s Health at the National Institutes of Health. Read more