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Pfizer starts US trials of experimental coronavirus vaccine

Preclinical studies are what companies do before they test vaccines in humans



A man enters the employee entrance of the Pfizer World Headquarters building in the Manhattan borough of New York, U.S., November 23, 2015.
Image Credit: Reuters

Pfizer Inc. has administered the first US patients with its experimental vaccines to fight the disease caused by the novel coronavirus, part of a bid to shave years off of the typical time it takes to develop a new inoculation.

The trials are being conducted at the NYU Grossman School of Medicine and the University of Maryland School of Medicine, the drugmaker said Tuesday."The short, less than four-month time-frame in which we've been able to move from preclinical studies to human testing is extraordinary," Chief Executive Officer Albert Bourla said in a statement.

Preclinical studies are what companies do in animals or in the lab before they test vaccines in humans. Drugmakers have been working with regulators to compress development times to stop the spread of the virus, which has infected more than 3.5 million people globally and killed more than 250,000.

New York-based Pfizer is working with BioNTech SE of Germany. The companies started testing the inoculations in patients in Germany in late April. Vaccine trials normally start by looking at safety, but in order to hasten the development of a Covid-19 vaccine, the drugmakers are looking at both safety and the immune-system response from the experimental shots.

Pfizer and BioNTech are in a race with companies including Johnson & Johnson, Moderna Inc. and dozens of other biopharmacuetical outfits and academic groups to come up with a safe and effective vaccine against the illness within the next year to 18 months. A handful are in human trials already, including Moderna's and ones from CanSino Biologics Inc., the Beijing Institute of Biotechnology and Inovio Pharmaceuticals Inc.Pfizer's U.S. trial will involve 360 patients in two age groups: 18 to 55, and 65 to 85, though trials in the older population will start only after safety and immune response are established in the younger group. The University of Rochester Medical Center/Rochester Regional Health and Cincinnati Children's Hospital Medical Center will eventually provide testing sites for the vaccines as well.

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"In an early vaccine trial, you actually monitor for a lot of potential reactions, you cast a very wide net, you actually ask the people to report to you everything they're feeling," said Pfizer's Phil Dormitzer, chief scientific officer for viral vaccines. "You don't know for sure until you've looked at a very large number."

Given what has happened with the development of other vaccines in the past, there is a risk that the new inoculation could actually make patients more susceptible to severe illness.

"Knowing there's a potential risk, we're going to proceed as though that's a real risk," Dormitzer said. "If it were to happen, we'll detect it as soon as possible"

Four Shots

Pfizer and BioNTech are looking at four different shots - and at a variety of doses and schedules - and will decide as the trials proceed which is the most effective. The aim is to have a shot ready for emergency use by the fall. The companies are also sharing data with regulators in real time, instead of analyzing it themselves before submitting it and applying for approval from regulators.Pfizer and BioNTech's potential vaccine harnesses a new type of RNA technology. After being injected into the body, the RNA slips into human cells and tells them to produce the viral proteins that then cause the body to develop protective antibodies. It's not technology that has been approved for use yet. The advantage is that RNA technology can move faster into trials because it doesn't involve brewing batches of protein or inactivated viral particles in living cells, which can take months.

Moderna is pursuing a similar approach, and started testing its vaccine on patients in March.One of the major challenges, beyond finding a safe and effective vaccine, will be ramping up production quickly enough to meet the world's needs. Pfizer says it should be able to make millions of doses this year and hundreds of millions in 2021, were it to succeed with one of its vaccine candidates.The RNA method is "actually a more natural mimic of what happens with a natural immune response to an invader," said Mark Mulligan, director of NYU Langone Vaccine Center, where the trials are taking place. "There certainly are things that I think are favorable in terms of the speed with which they can be produced and this idea that this is a natural type of vaccination."

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New York City has been an epicenter for Covid-19 in the U.S. The boroughs of Queens, Brooklyn and the Bronx rank as the three highest counties for deaths in the nation, according to Johns Hopkins University data. At NYU, screening began last week, with the first 10 to 15 people who volunteered. The first person was vaccinated on Monday.

"We've had a tremendous response of people interested," Mulligan said. "I think that it speaks highly of the desire of New Yorkers to fight back."

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