Why do some people get sicker than others from COVID-19?

Some people are at higher risk of getting sicker from COVID-19 than others. Those with some underlying medical conditions like Type 2 diabetes, high blood pressure, heart disease, and obesity are at increased risk for getting severely sick (source). Older adults are also at higher risk (source). Black or African American persons, Hispanic or Latino persons, and American Indian or Alaska Native persons have higher rates of hospitalization and death (source). Researchers are continuing to learn about the complicated biological and social reasons why some people get sicker than others.

Can COVID-19 symptoms vary in different people?

People with COVID-19 have had a wide range of symptoms reported – ranging from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus.

Why do some people get UTIs more frequently than others?

There may also be a genetic component to who gets UTIs. “Recent research shows some people have a certain receptor in their bladder wall that allows bacteria to stick more easily,” says Rosenblum.

Is there a link between blood type and risk of infection?

While some studies suggested a possible link, others stated that once infected, a person’s blood type doesn’t affect their disease outcomes at all. Since then, a more consistent pattern has started to emerge: people with blood type A now seem to be more at risk than those with blood type O.

How does the human immune system fight bacteria?

The main architects of this process are a set of human leukocyte antigen (HLA) genes, which code for molecules that fine-tune the body’s immune response. So when a bacterium gets into one of your cells, your HLA genes churn out proteins that flag the cell as infected so that specialized immune cells will swarm in to destroy it.

How does where you grow up affect your immune system?

Broad microbial exposure, in short, appears to train the immune system not to overreact to substances like animal dander. But regardless of where you grew up, if you’re unlucky enough to catch certain disease-causing bugs, they can throw your immunity off balance for years.