The experimental Oxford-AstraZeneca vaccine gives scientists hope as it triggers two immune responses: an increase in antibodies and a T-cell response.
Oxford University and AstraZeneca has developed a vaccine that has triggered immune responses against the coronavirus. The vaccine 'AZD1222', that has only minor side effects, will increase antibodies and a T-cell response. But the researchers say it's important to know that it's a progress report, it's too soon to declare victory. If the trials show a convincing end point, then the vaccine would be approved to be used further for the public.
According to new data published in the medical journal The Lancet, the experimental vaccine called AZD1222 has only minor side effects. The vaccine was tested on 1,000 patients and the results triggered two immune responses: an increase in antibodies and a T-cell response.
"So far, everything we've seen has been encouraging," said Naor Bar-Zeev, deputy director of the International Vaccine Access Center at Johns Hopkins University. He was not involved with this study. And he said there have not been any severe reactions.
There were 1,077 people from 18 to 55 years old that participated in the study enrollment that took place from April 23 to May 21.
Professor Adrian Hill, one of the study authors, said that the two-pronged immune response is ideal. The antibodies prevent healthy cells from becoming infected, and the T-cells work to kill cells that have already become infected.
Professor Adrian Hil also said; "Having both of these after vaccination — sometimes after a single dose, but much better after a second dose — is pretty encouraging,"
"Nobody can say for certain what you need to get protection in this disease because it's never been done before," he said. He added that the magnitude of the immune response was what they hoped for and was at the level "that seems to work in fundamental studies in animals and certainly right up there compared to using this sort of vaccine technology before."
Robert Gallo, who is the co-founder and director of the Institute of Human Virology at the University of Maryland School of Medicine, says it's too soon to declare victory.
"People are looking for antibodies that, in the lab, will block infection in a culture system, called 'neutralizing antibodies.' And that sounds very good," said Gallo, who is also the co-founder and international scientific adviser of the Global Virus Network. "Sometimes, that correlates with protection in vaccines. ... And sometimes it does not. And many times it does not."
This vacine targets the spike proteins that stud the outer surface of the coronavirus, giving it its crown-like shape. Robert Gallo is concerned that the antibodies these vaccines generate won't last long but the T-cell response measured in this study is compelling.
"It gave me a little more belief that this is going to be a viable pathway," he said.
A follow-up study is being done in the United Kingdom that has administered around 10,000 patients. Apart from that, another larger follow-up study is set to begin in the United States in the next few weeks with 30,000 patients.
Oxford’s Covid-19 vaccine produces a good immune response, reveals new study.— University of Oxford (@UniofOxford) July 20, 2020
Teams at @VaccineTrials and @OxfordVacGroup have found there were no safety concerns, and the vaccine stimulated strong immune responses: https://t.co/krqRzXMh7B pic.twitter.com/Svd3MhCXWZ
Professor Hill said; "As soon as together those trials show a convincing end point, then we would be in a position to apply for some sort of emergency use, regulatory approval that would allow the vaccine to be used," he said. "Because it's urgently needed in large numbers of people."