They confirm that Oxford and Astra Zeneca coronavirus vaccine is effective in 70% of cases

On the same day that Britain was the first country in the world to organize its vaccination against Covid with the Pfizer-BioNtech vaccine, a study published in the prestigious British scientific journal The Lancet gives another verdict expected amid the pandemic. Oxford University / Astra Zeneca Vaccine “It’s safe and effective”as confirmed by an independent scientific analysis, the researchers say that the verification will have a “major impact” in the fight against the virus.

The study, published by scientists in The Lancet, is the first peer-reviewed analysis to examine data from a Phase 3 vaccine trial.

Scientists working on the vaccine have stressed the importance of “transparency” and data sharing within the scientific community. They expect the vaccine to be approved for use in the UK “in the coming weeks”.

Efficiency

Almost 12,000 volunteers took part in the trial in the UK and Brazil, and the results show, on average, the efficacy of the vaccine was 70.4%.

In a group that received two standard doses of the Oxford Astra Zeneca vaccine, the efficacy was 62.1%. But in a group that accidentally received half a dose and then a full dose, efficiency increased to 90%. It is now they who create a scientific dilemma.

Professor Andrew Pollard, Director of the Oxford Vaccine Group and Chief Investigator of the Oxford Vaccine Trial, said: “Today we released the interim review for the Phase III trial. We show that this new vaccine has a good record of safety and efficacy against the coronavirus. », He assured.

“We are grateful with our test volunteers for working with us over the past eight months to get us to this important milestone, ”he continued.

The Oxford-Astra Zeneca vaccine it’s simple and cheap to produce. It can be manufactured in large quantities at low cost Unlike the Pfizer / BioNTech vaccine, it does not need to be stored at ultra-low temperatures and is easily transportable and exportable.

Professor Sarah Gilbert, professor of vaccines at the University of Oxford, hailed it as “probably the best day of 2020”.

“Following the demonstration of the vaccine’s efficacy in numerous preclinical studies, we now have clear evidence of the efficacy of the trial results presented in a peer-reviewed publication.

“Now, under regulatory review, we hope this vaccine will soon be used to start saving lives. “ assured Doctor Doctor Gilbert.

The trial is still ongoing. Questions remain as to how long the immunity will last and whether people might need a booster. .

It will be up to independent regulators to decide what doses can be given to people. The United Kingdom ordered 100 million doses of the Oxford vaccine.

The half-dose dilemma

The makers of the Oxford vaccine are the first to provide evidence that it can stop asymptomatic infection, a crucial sign that it could provide “herd or herd immunity.”

However, in another dilemma for regulators, the strongest effect seems to come from the half-dose regimen, which was discovered by chance during testing.

Scientists said the findings, published today in The Lancet, could further complicate the decision on which strategy to use, since the group that received this apparently more effective regimen was also smaller and did not include the elderly.

According to the results, those who received half the dose first and then a full dose had an estimated 90% protection against symptomatic disease and about 60% protection against asymptomatic infection. Those who participated in most of the trial, who received two full doses, had about 62% protection against disease, but were essentially unprotected against asymptomatic infection.

None of the vaccinees from the two groups was hospitalized.

The study shows that there remains considerable statistical uncertainty surrounding the results, which were based on 192 infections. For half-dose subjects, the 90% efficacy estimate is the best estimate of the confidence intervals, which range from 67 to 97%. For the corresponding asymptomatic estimate, the confidence intervals they range from 1 to 82 percent.

Sarah Gilbert, who led vaccine development, said publication of the article was a milestone. “It’s a very good day in the UK”, said. “We are not only seeing the first launch of the NHS vaccines against Covid-19. We can also present any information that people have requested from us.

She said the results, the first of one of three major vaccines to be published in a peer-reviewed journal, show that “the vaccine is safe. It is very effective. And we also know that it can be produced in large quantities and at low cost ”.

She and her colleagues also revealed more details about how the lower dose was produced. The half-dose regimen was administered to a subset of nearly 3,000 volunteers, after the arrival of a batch of vaccine which appeared to be of higher concentration.

Regulators

The team that performed the test discussed the issue with regulators. Instead of creating a new batch, it would have delayed testing, agreed to go ahead with half the dose.

They quickly realized that the batch had the correct concentration. But the positive results that were obtained, especially in side effects, convinced them and the regulators to continue with this dose.

They didn’t expect to see a marked difference. Andrew Pollard, who led the tests, said regulators should now review the results and make a decision.

“It complicates things. We didn’t start with the hope that there would be a difference between the groups. We think they would easily be combined to give a single number. As is, we have this additional intriguing result.

“It’s entirely up to regulators to look at the data and decide what they think the label should say in the end. It’s in your hands, ”said Dr. Pollard.

He added that in his opinion, we should be agnostic about the choice of vaccine. “What we need are vaccines in the arms of the people. We need more vaccines as soon as possible, ”he said.

Sure

The Oxford-Astra Zeneca team is the first to publish a peer-reviewed article on their end-stage vaccine trials. Data, efficacy and safety, were obtained from more than 20,000 participants in Great Britain, Brazil and South Africa.

Because nearly 7,000 of those involved took weekly swabs to check for infection, unlike other vaccines that have passed advanced stage trials, it also includes data on asymptomatic cases.

The main goal of a vaccine is to stop the disease. Unless you can also prevent people from getting an infection, whether asymptomatic or symptomatic, it is not certain that it can offer collective immunity.

Professor Pollard said the first data “suggests that there is something important here.” “We need more data to be sure. It is premature at this point to shout too loudly about this. “

Simon Clarke, of the University of Reading, said the document “presents regulators with a certain dilemma”.

“The data is more convincing for the group that received half a dose of the vaccine on their first injection. This does not only seem to confer better protection against the disease. It is in this group that there is a reduction in asymptomatic transmission of the virus. This is essential if you want to obtain collective immunity for better protection of the population. Unfortunately, this group was relatively small, which reduces the reliability of the results“explained the professor.

Alexander Edwards, of the same university, said the focus will be on the difference between these two doses. This will help us better understand the use of these vaccines, ”he said.