Dhaka, Sept. 24 -- A fourth Phase 3 clinical trial evaluating an investigational Covid-19 vaccine has begun enrolling adult volunteers, the US National Institutes of Health (NIH) announced on Wednesday.

The trial is designed to evaluate if the investigational Janssen Covid-19 vaccine JNJ-78436725 can prevent symptomatic Covid-19 after a single dose regimen, the NIH said in a release, reports Xinhua.

Up to 60,000 volunteers will be enrolled in the trial at up to nearly 215 clinical research sites in the United States and internationally.

The Janssen Pharmaceutical Companies of Johnson & Johnson developed the investigational vaccine, and is leading the clinical trial as regulatory sponsor.

It is the fourth large-scale phase 3 clinical t...