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.