With reports of the first human death from bird flu in the US, some Americans are feeling an uncomfortable flashback to the early days of Covid-19, when infectious disease experts were talking about a new virus that was sending people to the hospital with respiratory infections.

Bird flu, also known as avian influenza or H5N1, has infected more than 130 million birds over the past two years as it threatened commercial bird operations and recently led to the first human death in the United States.

The damage to those commercial industries has been severe. By the CDC’s accounting, bird flu has struck down nearly 131 million poultry and been found in 919 dairy herds across the country. The agency said there have been 66 confirmed human cases in the U.S. since last year, almost all of them people who worked on farms with infected cows or birds.