FILE PHOTO: A woman holds a small bottle labeled with a "Vaccine COVID-19" sticker and a medical syringe in this illustration…
FILE - A woman holds a small bottle labeled with a "Vaccine COVID-19" sticker and a medical syringe in this illustration taken April 10, 2020.

Tests of a possible COVID-19 vaccine are showing encouraging results, U.S. and German scientists say.  

U.S.-based Pfizer and the German firm BioNTech have teamed up for what they call Project Lightspeed, whose goal is a vaccine against COVID-19.

Both firms Wednesday announced “early positive data” from the most advanced of four potential vaccines they are developing, BNT162b1.

One month after being vaccinated, test subjects developed an antibody response to the coronavirus that was the same as or higher than that in the systems of those who had COVID-19 and had recovered.

Minor side effects included pain at the injection side and a low fever.

Pfizer and BioNTech tested the vaccine on just 45 people between 18 and 55. They cautioned that the tests were in the early stages and that they didn't know how long the vaccine would be effective.   

Both firms said they planned to continue with testing of four potential vaccines, including a much larger trial involving as many as 30,000 candidates.

About 25 different COVID-19 vaccines are in development around the world, and many have advanced to human trials, including in the United States and Brazil.  

While some medical experts say a vaccine could be ready as soon as the end of the year, others point out that a truly effective vaccine could take decades to develop, test and widely distribute.

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