The Omicron variant of the coronavirus is causing a dramatic rise in cases of croup, a dangerous respiratory condition usually seen in babies and toddlers, new data suggest. Additionally, new research sheds light on how a tuberculosis vaccine might help protect against COVID-19.

The widely used BCG tuberculosis vaccine will be tested on frontline care workers in Britain for its effectiveness against Covid-19, researchers running the UK arm of a global trial said.

As the COVID-19 pandemic spreads around the world, researchers and public health experts are casting about for older vaccines and antiviral drugs that might be used to treat the disease caused by the novel coronavirus SARS-CoV-2. Researchers in Australia are studying an older treatment, a vaccine once used to prevent tuberculosis called the bacillus Calmette-Guerin (BCG), which has been used for about 100 years.

The U.S. FDA approved Merck & Co. Inc.’s Keytruda for a hard-to-treat form of bladder cancer, making the blockbuster therapy the first new treatment for the cancer in more than two decades.

Investigators with the National Institutes of Health conducted research on monkeys that injected a bacilli Calmette-Guerin (BCG) vaccine directly into the bloodstream, producing dramatically improved effectiveness compared to injecting the vaccine into the muscle or skin.