Within the “very cautious” American human trial of a COVID-19 vaccine

Two American pharmaceutical giants, Pfizer en Modern, are in the final phase of coronavirus vaccine development, and University of Oxford is expected to begin large-scale human trials of its vaccine this month in the US. CBS News got an in-depth look at what’s happening in this phase before the vaccine is approved for public use.

For Dr. Victoria Smith, who practices family medicine near New Orleans, COVID-19 is personal. She lost three patients to the virus.

“I wanted to be part of the solution,” she told CBS News’ chief medical correspondent Dr. Jon LaPook. At the end of July, Smith became one of the first of 30,000 participants in Pfizer’s Phase 3 vaccine test.

“I’m not an immunologist, but by being part of a trial I can also be part of that research front,” she said.

She received her first dose at Ochsner Medical Center in Louisiana. It is a double-blind study, which means that neither she nor the researchers know whether she has the vaccine or just a placebo.

Each week, Pfizer sends packages of the vaccine and placebo to the Ochsner Phase 3 trial site. The vaccine is then stored in a freezer at a temperature of at least -60 degrees Celsius (-76 Fahrenheit) to keep it stable.

Smith said she had no doubt about the trial. “I trust the process,” she said.

To be approved by the Food and Drug Administration, a COVID-19 vaccine must prevent or reduce the severity of the disease in at least 50% of the vaccinated people.

“There’s no evidence that the vaccine hardly makes the disease worse. That’s actually, really, very encouraging,” said Dr Kathryn Edwards, who sits on Pfizer’s Security Committee.

Once a week, the five members of the commission have to video chat to look at data carefully and look for any negative effects – especially serious ones that lead to hospitalizations.

“We are very, very careful in how we look at the data,” Edwards said. “Sure if there were harsh reactions, we would get that information right away.”

Edwards said there has been no evidence to date that the vaccine has caused serious reactions, but that mild reactions are common and should not be prevented from being vaccinated.

“You may have a bad arm, or you may have a little tenderness, or you may have a little headache, or you may have a little fever. Those are things to expect,” she said. “It’s just that your immune system attacks and you make a better response.”

Trial participants are required to self-monitor their symptoms and log on to an app, record their temperature and each reaction every day for a week after each injection. They will be asked to continue reporting symptoms at two weeks for two years.

On Wednesday, after 21 days, Smith received her final dose. Honest test results show that a second shot enhances the neutralizing antibodies that block the virus’ ability to attack our bodies.

“If you look at the immune responses in the people who got one dose and two, the two doses, their immune response was higher. So I think … they’ll probably need two doses,” Edwards said.

But a fax is not expected to mean an immediate return for the way things were.

“If the vaccine is 50% effective, it will not reduce any disease,” Edwards said. “There’s social distance, the masks, these things should probably go on and people will have to go through what they thought about what their activities are and the implications they have for the rest of the community.”