(Bloomberg) -- An experimental Covid-19 vaccine developed by CanSino Biologics of China was safe and generated an immune response in an early study in humans.

The vaccine stimulated production of both antibodies that can stop infection along with immune T-cells, according to a report published Friday in The Lancet medical journal. Further research is needed to show its effectiveness against the virus, according to the study funded by CanSino and conducted by researchers from the Beijing Institute of Biotechnology and other organizations.

Drugmakers and universities are rushing to develop vaccines against the coronavirus that’s confining people to their homes and shuttering businesses. The University of Oxford and AstraZeneca Plc also said Friday that they’re recruiting more than 10,000 patients for advanced studies of a different experimental inoculation.

The results of the CanSino vaccine study “represent an important milestone,” said Wei Chen, a professor at the Beijing institute that carried out the study, in the report. “However, these results should be interpreted cautiously. The challenges in the development of a Covid-19 vaccine are unprecedented, and the ability to trigger these immune responses does not necessarily indicate that the vaccine will protect humans from Covid-19.”

The trial in 108 adults recruited from Wuhan, China, where the virus was first detected, demonstrated promising results after 28 days. The final results will be evaluated in six months, according to the report.

©2020 Bloomberg L.P.