Eli Lilly is testing a way to prevent covid-19 that’s not a vaccine

Nurses and patients in some US assisted living facilities will receive an antibody drug to prevent covid-19 infection, according to drug company Eli Lilly.

The drug: Early in the coronavirus pandemic, companies searched the blood of covid-19 survivors for potent antibodies against the novel virus. Eli Lilly's drug is one of these Y shaped proteins-it's a natural antibody manufactured at larger scale.

The trial: To carry out the study, which will involve 2,400 people, Lilly will work with the National Institutes of Health to target nursing homes with covid-19 outbreaks. In some areas, elderly residents in nursing homes account for the majority of covid-19 deaths.

How it works: Just like natural antibodies, Lilly's antibody should grab onto the virus and block it. Similar antibody treatments proved effective in treating Ebola disease, but the goal here is to prevent infection by giving the drugs earlier. Prevention with antibodies is known to work. There is an antibody shot given to babies that prevents RSV, a respiratory infection striking newborns.

Passive immunity: Vaccines expose the body to a part of the pathogen, leading to active immunity"-your body learns to makes its own antibodies against a germ. Adding antibodies artificially generates passive" immunity which lasts only as long as the antibodies. Researchers say antibodies, delivered usually via an IV, can stay in the bloodstream for weeks or months.

Plan B: Antibody treatments could reach the market before a vaccine. It could be a big deal for protecting health care workers and the most vulnerable. A report today from the American Biodefense Institute calls passive immunity the next generation of pandemic response."