China’s CanSino Biologics will initiate clinical trials of an experimental Covid-19 vaccine that is inhaled, instead of injected.

China’s CanSino Biologics Inc. said the efficacy rate for the company’s single-dose Covid-19 vaccine may fall over time although it should still have a rate of 50 percent or more five to six months after inoculation.

As the world awaits the production and distribution of hundreds of millions of doses of COVID-19 vaccines that have been granted emergency use authorization, biopharmaceutical companies and manufacturers are developing the next wave of vaccines and therapeutics to combat the pandemic.