Johnson & Johnson (NYSE:JNJ) announced on Wednesday that it expects to begin a phase 1/2a clinical trial of its COVID-19 vaccine candidate Ad26.COV2-S, recombinant, in the second half of July. The company previously projected that the early-stage clinical study would begin in September.

In February, Johnson & Johnson established a partnership with BARDA (the Biomedical Advanced Research and Development Authority) to develop a COVID-19 vaccine candidate at an accelerated pace. Chief Scientific Officer Paul Stoffels noted that the strong preclinical data observed thus far and the company's discussions with regulatory authorities were key in allowing it to speed up the development program.

Gloved hands holding COVID-19 vaccine syringe

Image source: Getty Images.

The early-stage clinical trial will be conducted in the U.S. and in Belgium. Johnson & Johnson plans to enroll 1,045 healthy adults between the ages of 18 to 55, plus adults aged 65 and over.

Johnson & Johnson is also talking with the National Institutes of Allergy and Infectious Diseases about the possibility of starting a phase 3 study of its COVID-19 vaccine sooner if the early-stage studies produce positive results. The healthcare giant is ramping up manufacturing capacity for the experimental vaccine even before clinical testing is completed, with a goal of being able to supply over 1 billion doses next year if the vaccine proves safe and effective.