Researchers around the world scrambled to create a safe and effective vaccine to protect against the novel coronavirus. Now some of those vaccines are producing results in trials. Scientists at Oxford University in Great Britain say their experimental vaccine did well in an early trial. It prompted a protective immune response in hundreds of people who got the shot.
The British researchers first began testing the vaccine in April in about 1,000 people. Such early trials are designed to evaluate safety. They also detect the patients’ immune responses. But it’s still too soon to say whether those responses provide long-term protection against the virus.
Dr. Adrian Hill is the director of the Jenner Institute at Oxford. He is cautiously optimistic about the results, which involved participants from ages 18 to 55.
“We are seeing good immune response in almost everybody,” says Dr. Hill. “What this vaccine does particularly well is trigger both arms of the immune system.”
Hill says that neutralizing antibodies are produced first in the patient. Those are molecules which are key to blocking infection. In addition, the vaccine also causes a reaction in the body’s T-cells, which destroy cells that have been taken over by the virus. That keeps the infection from spreading within the infected person’s body.
The experimental COVID-19 vaccine caused minor side effects including fever, chills, and muscle pain for a few participants.
Larger trials involving about 10,000 people in the UK, South Africa, and Brazil are underway. Another trial of about 30,000 people in the United States will start soon.
Hill says Oxford’s vaccine is designed to reduce disease and transmission. It uses a harmless cold virus known to infect chimpanzees. That virus is engineered in a lab so that it can’t spread. It carries just a part of the coronavirus with it—the spike protein that attaches to human cells when the full virus infects a person. By God’s design, the human body recognizes the foreign protein as an enemy, and that triggers an immune response designed to fight off that enemy very specifically.
Oxford has partnered with drug maker AstraZeneca to produce the vaccine globally. If trials keep coming back positive, that company has committed to making two billion doses.
Meanwhile, other groups and pharmaceuticals companies are reporting positive trials with various other vaccines against the virus.
Pfizer and its German partner, BioNTech, report having a vaccine that works similarly to the Oxford shot. American researchers announced last week that a COVID-19 vaccine tested in the United States also boosted immune responses in tests and would move soon into final testing. That vaccine was developed by the National Institutes of Health in cooperation with Moderna, a pharma company.
Nearly two dozen vaccines are in various stages of human testing worldwide.
(A doctor takes blood samples for use in a coronavirus vaccine trial in Oxford, England, on Thursday, June 25, 2020. John Cairns, University of Oxford via AP)