May 7, 2020 - Today in the world of coronavirus news –

Pfizer has launched a phase I/II clinical trial for a vaccine for COVID-19. It is collaborating with an immunotherapy company, BioNTech, and testing four different vaccine candidates at once, the company says.

It expects to produce millions of vaccine doses yet in 2020.

The platform under study is similar to the one used by Moderna, which hopes to begin a phase II study by the summer.

According to Pfizer, the dosing of the first group of volunteers was done in Germany last week. Stage 1 of the phase I/II trial in the U.S. will enroll up to 360 healthy people in two age groups, 18-55 and 65-85. Older adults will be immunized once a safe a dose level is established. Sites include NYU and the University of Maryland. Enrollment is scheduled to begin at the University of Rochester and Cincinnati Children's Hospital soon.

These types of vaccines use messenger RNA to convey genetic information to the body's cells. Once mRNA in a vaccine is in the cell, the cells can translate this genetic information to create an immune response.

Because the companies are evaluating four different mRNA candidates at once, they can shift gears quickly if one does not work, says Litjen (L.J.) Tan, PhD, chief strategy officer for the Immunization Action Coalition. He suggests thinking of the technology as an old-fashioned cassette tape. If you don't like the music, you can switch to another tune. These mRNA ''cassettes" or platforms ''use recombinant DNA technology to drop in pieces of RNA that will be used by the cell to make the protein to stimulate the immune response," he says. If one doesn't work, they can move on to another.

"I would say in about 2 months, they will know immediately if the vaccine is safe and if the vaccine stimulates the immune response."

As of early May, 123 vaccines for COVID-19 are under study, in various phases of development, according to Faster Cures, a center of the Milken Institute, which tracks vaccines and treatments for COVID-19.

Show Sources

Pfizer press release: "Pfizer and BioNTech Dose First Participants in the U.S. as Part of Global COVID-19 mRNA Vaccine Development Program," May 5, 2020.

Litjen (L.J.) Tan, PhD, MS, chief strategy officer, Immunization Action Coalition.

Milken Institute's Faster Cures: COVID-19 Treatment and Vaccine Tracker.

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