Pfizer and BioNTech have commenced the dosing of participants in a Phase I/II clinical trial assessing the BNT162 vaccine candidate to protect against Covid-19 in the US.

The study is part of a global development programme and the dosing of initial participants in Germany was concluded last week.

During the Phase I/II protocol, the safety, immunogenicity and optimal dose level of four mRNA vaccine candidates will be assessed in a single, continuous study. The trial’s dose level escalation part in the US will involve up to 360 healthy participants.

NYU Grossman School of Medicine and the University of Maryland School of Medicine in the US are currently dosing volunteers.

The University of Rochester Medical Center/Rochester Regional Health and Cincinnati Children’s Hospital Medical Center are set to be open for enrolment soon.

Pfizer chairman and CEO Albert Bourla said: “With our unique and robust clinical study programme underway, starting in Europe and now the US, we look forward to advancing quickly and collaboratively with our partners at BioNTech and regulatory authorities to bring a safe and efficacious vaccine to the patients who need it most.

“The short, less than four-month timeframe in which we’ve been able to move from pre-clinical studies to human testing is extraordinary and further demonstrates our commitment to dedicating our best-in-class resources, from the lab to manufacturing and beyond, in the battle against Covid-19.”

BioNTech will be responsible for clinical supply of the vaccine from its mRNA manufacturing facilities in Europe, during the clinical development stage.

Pfizer and BioNTech are also preparing to scale up manufacture for global supply.

Pfizer intends to leverage its manufacturing network and make investments towards a  programme that could help produce millions of vaccine doses this year and hundreds of millions next year.

The company has so far decided to engage its manufacturing sites at Massachusetts, Michigan and Missouri in the US and at Puurs in Belgium to produce a Covid-19 vaccine.

BioNTech will boost the production at its mRNA sites in Mainz and Idar-Oberstein, Germany.

After potential regulatory approval, the partners will co-commercialise the vaccine globally, except in China, where BioNTech is working with Fosun Pharma.