A coronavirus vaccine being developed by the University of Oxford and AstraZeneca is safe and shows signs of inducing an immune response, according to early clinical trial results published Monday in the medical journal The Lancet.
The trial did not look at whether the vaccine prevents coronavirus infection, however. That’s a question that will be answered in trials that are currently ongoing.
The trial results found that it generated two “strong” immune responses: the production of both antibodies and T cells, which find and attack virus cells.
“We’re getting both sides of the immune system stimulated and that is fairly unusual for vaccines,” Adrian Hill, director of the Jenner Institute at Oxford University, told NBC News.
It is “good news — another step forward on the long road” to having a COVID-19 vaccine,” said Dr. William Schaffner, an infectious disease expert at Vanderbilt University Medical Center in Nashville. Schaffner was not involved in the vaccine research.
Dozens of teams across the world are working on potential coronavirus vaccines.
Moderna, a Cambridge, Massachusetts-based biotech company, published its phase 1 trial results of its vaccine last week, and announced plans to begin its final phase of human testing at the end of July. In the phase 1 trial, researchers reported that all 45 volunteers developed antibodies key to fighting the coronavirus.
Both the Moderna and Pfizer COVID-19 vaccines in development also suggested immune responses for antibodies and T cells, though Moderna’s T cell response was weaker.
In the Oxford study, the T cell response was noted within 14 days of receiving the vaccine. Immunity was detected for at least 56 days after getting the shot. It’s unclear how long that will last.
Fatigue and headache were the most common side effects reported by the 1,077 study participants, all adults between the ages of 18 and 55.
The clinical trial did not establish whether the vaccine protects against coronavirus infection. That will be determined in the phase 3 trials, which are currently taking place in Brazil, South Africa and the United Kingdom. Trials will also be started in other parts of the world, including the United States.
“We want to look at the efficacy of the vaccine in different populations,” Hill said.
The vaccine is made from a weakened form of a common cold virus, called an adenovirus, that’s been genetically modified to carry instructions for cells to make the coronavirus’s notorious spike protein. The idea is that, if the vaccine can instruct human cells to make this protein, the human system can learn to recognize it and better protect against infection.
Early research found that the experimental vaccine induced antibody production in six rhesus macaques. These monkeys are considered to be good proxies for how drugs could work in people because they share a majority of their genes with humans. When the researchers exposed the vaccinated animals to the coronavirus, they did not develop pneumonia or other lung problems.
The global race toward a vaccine for COVID-19 — which, by Monday afternoon had sickened nearly 15 million people worldwide — is, indeed, moving far more quickly than work on previous vaccines.
And there is unlikely to be a single “winner.” Multiple vaccines will likely be necessary to treat the entire world.
Researchers “are working very rapidly. We’re saving time, because we’re doing some things simultaneously, that we used to do in sequence,” Schaffner said. “No corners are being cut.”
Asked whether a finished Oxford vaccine was likely in the next year, Hill said the research was still targeting 2020.
“A vaccine later this year is not impossible. A lot of things would have to go right for that to happen and to be deployed in 2020, but we’re still targeting that.”