• The study published in The Lancet reiterated the trial findings for the vaccine that showed an average effectiveness of 70% in protecting against the coronavirus.
• Sarah Gilbert, the Oxford vaccinology professor who led the project, said it was a "really good day for the U.K., this is probably the best day we've had in 2020."

LONDON — The coronavirus vaccine developed by British pharmaceuticals giant AstraZeneca and the University of Oxford is the first to have its late-stage trial results independently reviewed and published in a peer-reviewed medical journal.

The study, published Tuesday in The Lancet, reiterated the trial findings for the vaccine that showed an average effectiveness of 70% in protecting against the coronavirus.

It also confirmed findings for the dosage regimens used in the trials: 62% effectiveness for two full doses and 90% efficacy for the half-then-full dose regimen.

At a press conference Tuesday, the Oxford vaccinology professor who led this coronavirus vaccine project, called it a "really good day for the U.K., this is probably the best day we've had in 2020."

"Not only today are we seeing the first rollout of NHS vaccinations against Covid-19, (but) from our side we are able to present to you our data in a full peer-review publication with all of the information that people have been asking us about," said the professor, Sarah Gilbert.

"And we now see that the vaccine is safe, it's highly effective and we also know that it can be manufactured in large quantities and at a low price," Gilbert said, adding that it is hoped the vaccine will receive regulatory approval "in the coming weeks."

Trial age groups

Trial data running up to Nov. 4 was analyzed from 23,745 adult participants in the U.K., Brazil and South Africa. Some 82% of the trial participants were ages 18 to 55.

People age 56 years and over were recruited to take part later. The University of Oxford said the effectiveness of the vaccine in this older age group could not yet be assessed but would be in future analyses after it had accrued more data.

The age groups tested in the trials had been a concern for chief of the White House's Operation Warp Speed, Moncef Slaoui, and others in the U.S., who have pointed out that the 90% efficacy rate was only shown for a lower risk group, which numbered 2,741 people below age 55. 

The vaccine was found to be safe, the Lancet study said, with only three out of the 23,745 participants experiencing "serious adverse events that were possibly related to a vaccine," over an average 3.4 months.

All three have since recovered or are recovering and continue to be part of the trial.