CanSinoBIO’s inhaled COVID-19 vaccine candidate was found to trigger immune responses with no serious side effects reported, according to an early-stage clinical study.

The inhaled two-dose candidate is modified from CanSinoBIO’s injected COVID-19 jab Ad5-nCoV vaccine, which is already approved in China and other countries around the world.

Results from a Phase I clinical trial, published in The Lancet, found that two-doses of the inhaled Ad5-nCoV vaccine can trigger a similar immune response to a single-dose of the injected version.

The inhaled version was also found to trigger neutralising antibodies and T cell responses after one dose.

The study also found that the inhaled version of the vaccine did not cause serious side effects, demonstrating an encouraging safety profile in the early-stage trial.

A number of drugmakers are also developing inhaled treatments for COVID-19, including Verona Pharma.

UK-headquartered Verona announced at the beginning of the year that it had completed enrolment in a pilot study evaluating the efficacy of ensifentrine delivered via pressurised metered-dose inhaler (pMDI) formulation in patients hospitalised with COVID-19.

The US-based study is evaluating the effect of ensifentrine on key outcomes in patients hospitalised with COVID-19, including facilitation of recovery from the viral infection, clinical status improvement and reduction in supplemental oxygen use and progression to mechanical ventilation.