Oxford University announces that its COVID vaccine is 90% effective

"We have a vaccine for the world," said researcher Andrew Pollard, from the University of Oxford, at a press conference on Monday.

Its experimental vaccine against covid has an average efficacy of 70% and can reach 90% depending on the dose regimen, according to preliminary results presented by the British institution.

“We do not have serious or hospitalized cases among those vaccinated.

This is very good news, ”said Sarah Gilbert, co-leader of the experimental vaccine research.

Scientists from Oxford and the British pharmaceutical company AstraZeneca are running a clinical trial with some 24,000 people in the UK, Brazil and South Africa.

The first analysis of their data, after detecting 131 cases of covid, suggests an efficacy of 62% when two doses of the experimental vaccine are administered, with an interval of one month, and up to 90% when half dose is first punctured and then a full second.

Researchers are doing experiments to understand this phenomenon.

Oxford's experimental vaccine is one of the most advanced in the world, along with those of the US companies Pfizer and Moderna, which have already announced preliminary efficiencies of around 95%.

The European Commission in August signed an agreement with AstraZeneca to buy 300 million doses of the Oxford vaccine - with an option for an additional 100 million - to be distributed in European countries based on their population.

Oxford and AstraZeneca have committed to providing the vaccine on a non-profit basis during the pandemic, a decision that would remain forever in resource-poor countries.

The pharmaceutical company has already signed agreements to sell 3 billion doses worldwide, according to its figures.

The price of each dose would be around three euros, compared to 15 euros for Pfizer's vaccine and 21 euros for Moderna's.

Matt Hancock, British Secretary for Health.

On video, his assessment of the AstraZeneca vaccine.REUTERS / VIDEO: REUTERS-QUALITY

Researchers have not observed any serious adverse effects among the 24,000 clinical trial participants, some of them vaccinated in April.

The team is recruiting more volunteers in the US, Kenya, Japan and India and expects to reach 60,000 people by the end of the year.

The scientists have announced that they will publish a full analysis of their preliminary results in an impact scientific journal in the coming days.

Then the main unknowns about its experimental vaccine will be clarified, such as the level of protection of the elderly and to what extent asymptomatic transmission of the virus is prevented.

Oxford's experimental vaccine is made from a weakened version of a chimpanzee common cold adenovirus, modified with genetic information from the new coronavirus to train the human body's defenses without the risk of covid.

Researchers from the British university have highlighted that their vaccine can be kept in the refrigerator, at temperatures between 2 and 8 degrees, which facilitates its distribution throughout the world.

There are already 10 countries manufacturing the vaccine on a large scale, according to a statement from Oxford.

The Spanish Government authorized on October 20 the purchase of 31.5 million doses of the British vaccine, with the aim of immunizing more than 15 million people between December and June.

If it is confirmed that only half a dose is required in the first injection, the amount purchased by Spain would be enough to vaccinate 21 million citizens.

The Minister of Health, Salvador Illa, stated in October that the first three million doses would arrive in December.

"The trial has not yet been completed, but these preliminary results indicate promising efficacy," says virologist Isabel Sola, co-director of another experimental vaccine against covid at the National Center for Biotechnology in Madrid.

The researcher highlights that among those vaccinated with the Oxford injection, in addition to an absence of seriously ill patients, a reduction in asymptomatic cases is observed, which suggests that the vaccine can prevent the transmission of the virus between people, not only prevent the more severe symptoms.

“This would suggest that there is sterilizing immunity, which is the ideal one to eradicate the virus.

It will have to be confirmed, but this would be a strength of this candidate, ”says Sola.

"Another of its potential advantages is that, possibly, their production and conservation are simpler than those of RNA vaccines [such as those from Pfizer and Moderna], so distribution and logistics would be simplified", reflects the virologist.

“They have not clearly said if the vaccine is effective in the most vulnerable groups due to age or previous pathologies.

As always, we will have to wait for the complete data to be published ”, adds Sola.

“The Oxford data is in line with the expected pattern and it is normal that they have made a wake-up call after the announcements of Pfizer and Moderna of the past weeks.

They have used the same type of field test and it is still difficult to assess the protection achieved with respect to the most severe cases of the disease.

For the rest, his data seems correct, "says scientist Vicente Larraga, father of another experimental vaccine against covid at the Margarita Salas Biological Research Center (CSIC), in Madrid.

Larraga is not surprised by the differences in efficacy depending on the dose, due to the unique functioning of the human immune response.

"Half a dose can have a higher response than a standard dose," he says.

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