Britain on Tuesday began a large-scale trial of a new COVID-19 treatment in which patients inhale aerosolized interferon beta proteins into the lungs with a nebulizer. The treatment, developed at Southampton University Hospital and produced by biotech firm Synairgen, cut the odds of COVID-19 patients developing severe symptoms by nearly 80 percent, according to a small, phase 2 trial of 100 patients. The new phase 3 study involves more than 600 subjects in 20 countries, half of whom will get the treatment and half a placebo inhalant.

The body produces interferon beta to fight off viral infections, but the new coronavirus appears to suppress production of the proteins as part of its mechanism to evade patients' immune responses, BBC News reports. Synairgen hopes a direct shot of aerosolized interferon beta straight to the lungs will provoke a strong anti-viral response. The early results are promising, but experts warn that promising treatments don't always pan out.

"We've had other drugs in similar circumstances, we've had hydroxychloroquine, for example," Dr. Lamis Latif tells BBC News. "But again, when that reached further trials, it wasn't as promising as it initially made up to be.