It was just last week that Pfizer (NYSE:PFE) and BioNTech (NASDAQ:BNTX) got permission to start a phase 1/2 clinical trial of BNT162, their SARS-CoV-2 vaccine candidate, in Germany.

Seven days later and the companies have already completed inoculating the first group of patients in the study. Of course, that group only consists of 12 participants -- and there are presumably plenty of people eager to participate given the lack of an approved coronavirus vaccine -- but the speed is still impressive nevertheless.

The safety portion of the clinical trial involves testing a range of doses from 1 microgram to 100 micrograms, and will eventually enroll 200 participants. BioNTech has developed four different variations of its mRNA vaccine. For three of the vaccines, the clinical trial will include booster shots after the initial vaccine to hopefully increase the amount of antibodies the participants generate. The fourth vaccine is a self-amplifying mRNA, so the hope is that only a single dose of the vaccine will be required.

Gloved hands giving an injection into a shoulder

Image source: Getty Images.

Pfizer licensed the rights to BioNTech's coronavirus vaccine in April for $72 million in cash and a $113 million equity investment. BioNTech is also eligible for milestone payments of up to $563 million. The companies will co-market the vaccine worldwide, except in China, where BioNTech licensed it to Fosun Pharma.

Pfizer and BioNTech expect to gain permission from the Food and Drug Administration to expand their clinical trial to the U.S. shortly. There's no word yet on a timeline for the development of the vaccine in China.