AstraZeneca vaccine is safe and effective, researchers say

The symptomatic covid-19 vaccine developed by the English University of Oxford with pharmaceutical company AstraZeneca has acceptable and effective security levels, according to preliminary results from phase 3 clinical trials published this Tuesday in the journal “The Lancet”.

Oxford experts today published the results of their clinical trials for the first time, which has absence of hospitalization or “serious illness” in vaccinated individuals of the group.

These results on the clinical efficacy of the drug (AZD1222) – reviewed by other independent experts – come from a pre-specific Phase 3 group analysis carried out in the United Kingdom and Brazil with 11,636 subjects, at to which are added “tolerance data” on a total of 23,745 people tested in four tests developed in the UK, Brazil and South Africa.

The Oxford team, led by Andrew Pollard and Sarah Gilbert, found that their vaccine, given in two doses (preparatory and booster), it is effective in an average of 70%, although varying the amount of each dose affects the result.

Thus, when a half dose is administered followed by a full dose, the vaccine’s efficacy level is 90% and it drops to 62% when volunteers receive two full doses of the preparation.

Of the 23,745 people vaccinated, only three over an average period of 3.4 months experienced “serious side effects” this could be attributed to the vaccine, although all have recovered or are recovering and continue to participate in clinical trials, Oxford experts said in a statement.

“In future reviews, with the inclusion of more data as it becomes available, we will study the differences in key subgroups – such as older adults – various ethnicities, dosages, timing of booster injections, etc. we will determine which immune responses offer protection against infection or diseasesaid Merryn Voysey, one of the study’s authors.

Pollard, for his part, pointed out that “the effectiveness of our vaccine” has exceeded the thresholds set by the health authorities, including those in the European Union (EU), which has not yet given approval to this medicine.

“We will only achieve control of the pandemic if the authorization, manufacture and distribution of these vaccines can be done on an unprecedented scale and the vaccination process reaches the most vulnerable,” said the Oxford scientist.

AZD1222 was made from the genetic modification of a common cold virus that affects chimpanzees, but does not cause disease in humans and is able to express the S protein of SARS-CoV-2, the coronavirus which causes covid-19. .