Johnson & Johnson begins two-dose trial of its Coronavirus vaccine

New York: Drugmaker Johnson & Johnson has launched the Phase 3 trials of the two-dose regimen of its investigational vaccine candidate for the prevention of Covid-19.

The vaccine candidate, JNJ-78436735, is being developed by the Janssen Pharmaceutical Companies of Johnson & Johnson.

The company is starting the two-dose trial in addition to the Phase 3 study of the single-dose regimen which continues to enrol and vaccinate study participants.

While the single-dose regimen is proceeding to enrol up to 60,000 participants worldwide, the new trial will study the safety and efficacy of a two-dose regimen of the vaccine candidate in up to 30,000 participants worldwide.

The two trials will run in parallel, Johnson & Johnson said on Sunday.

"While a potentially safe and effective single-dose preventive Covid-19 vaccine would have significant benefits, particularly in a pandemic setting, Janssen's Covid-19 vaccine programme has been designed to be extremely thorough and driven by science," the company said.

"As such, we are investigating multiple doses and dosing regimens to evaluate their long-term efficacy," it added.

The Phase 3 trials follow positive interim results from the company's ongoing Phase 1/2 clinical study, which is studying the safety profile and immunogenicity of both single-dose and two-dose vaccination.

The interim analysis showed that a single dose of the Covid-19 vaccine candidate induced a robust immune response and was generally well-tolerated.

The two-dose Phase 3 trial is designed to evaluate the safety and efficacy of the vaccine candidate versus placebo in adults with and without comorbidities associated with an increased risk for severe Covid-19.

The study will assess the efficacy of the investigational vaccine after both the first and second dose to evaluate protection against the virus and potential incremental benefits for duration of protection with a second dose.

Janssen will aim to enrol participants in Belgium, Colombia, France, Germany, the Philippines, South Africa, Spain, the UK and the US.

The Janssen Covid-19 vaccine candidate leverages the company's AdVac technology platform, which was also used to develop and manufacture Janssen's European Commission-approved Ebola vaccine and construct its Zika, RSV (respiratory syncytial virus), and HIV investigational vaccine candidates.