Pfizer Coronavirus Vaccine Enters Human Testing in U.S.

Researchers have begun giving healthy volunteers in the U.S. an experimental coronavirus vaccine developed by Pfizer Inc. and partner BioNTech SE, the latest study exploring a potential defense against the respiratory disease.
Researchers at the New York University Grossman School of Medicine in Manhattan and the University of Maryland School of Medicine in Baltimore said Tuesday they began injecting people with the first of four vaccine candidates from Pfizer and Germany’s BioNTech.
The clinical trial will help the researchers evaluate whether the candidates are safe, which produces the strongest immune response that could fend off the coronavirus and what the dose should be. Pfizer plans to advance the candidate that proves most promising. Testing of the vaccine candidates in Germany began last month.
Results from the 360-person study in the U.S. could come as early as next month, but the vaccine will still need to undergo additional testing in more patients, said Kathrin Jansen, Pfizer’s head of vaccine research and development.
Pfizer will track the progress of the study to pick the most promising vaccine candidate, Dr. Jansen said.
The plan is to “weed out, weed out, weed out, focus on what’s good and move on,” Dr. Jansen said. “It’s a quick elimination.”
A vaccine could be ready for emergency use as early as the fall if testing indicates it works safely, Pfizer Chief Executive Albert Bourla told The Wall Street Journal last week, though the company would keep studying it in clinical trials.
The U.S. government has the authority to grant limited use of a vaccine or drug during a health emergency, before testing is complete.
Several potential coronavirus vaccines have entered human testing, including candidates from Moderna Inc. and Oxford University.
The vaccine efforts have advanced quickly compared with typical vaccine R&D timelines, though some experts have expressed concern over whether testing will be rigorous enough to adequately assess if the shots can safely protect people from contracting the coronavirus.
“The question is, what steps are you skipping?” said Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, who developed a vaccine for a common disease in young children called rotavirus that causes diarrhea and vomiting.
Adding to the challenges of deciphering whether a coronavirus vaccine works, researchers say, is uncertainty about how immunity develops against the virus.
Without that knowledge, researchers are relying on their understanding of previous coronaviruses and antibodies that neutralize viruses, said Kirsten Lyke, a professor of medicine at the University of Maryland School of Medicine, who is helping lead the Pfizer trial.
The Pfizer and BioNTech vaccine will initially be studied in adults 18 to 55 years old, and eventually will enroll older volunteers, Pfizer said.
After receiving the first dose, patients will receive a second dose three weeks later. Pfizer will test other doses later on, including a single shot, Dr. Jansen said.
Four out of every five study subjects will get the vaccine, while the remaining subjects will take a placebo.
The vaccine uses a gene-based technology known as messenger RNA. Messenger RNA, or mRNA, carries instructions from DNA to the body’s cells to make certain proteins. An mRNA vaccine has never been approved to prevent any infectious disease.
Mark Mulligan, director of the Vaccine Center at NYU Langone Health, said he doesn’t expect challenges enrolling patients.
“People, frankly, are sick of this virus and they want to do whatever they can to fight back,” he said. “The public recognizes that in order to start returning to normalcy, we’ve got to get people protected, and vaccines hold the greatest hope for that.”
Melissa Honkanen, 42 years old, of New York City, enrolled in the study after hearing about it from her husband, a pediatrician at NYU Langone, because she wanted to be helpful.
“It’s really hard to see all of this happening,” said Ms. Honkanen, a yoga instructor. “We’re in a world where we can’t hug each other or be social and active.”
Aside from working on a vaccine, Pfizer is also trying to develop an antiviral treatment that could begin testing this summer, and it is testing whether rheumatoid-arthritis drug Xeljanz helps fight Covid-19, the disease caused by the coronavirus.
Pfizer plans to soon manufacture the vaccines at its facilities in Massachusetts, Michigan and Missouri, as well as Puurs, Belgium, with additional locations to come.

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