The vaccine developed by the University of Oxford and the pharmaceutical company AstraZeneca is safe and effective. That is the conclusion of the first comprehensive and peer-reviewed efficacy results that have been published in the prestigious medical journal The Lancet. The data is based on a set of phase three trials conducted in the UK and Brazil involving 11,636 volunteers, along with safety data from a total of 23,745 participants in four trials in the UK, Brazil and South Africa. The data indicates, according to the publication, that this immunization is 62% effective for those who receive two full doses and 90% for those who receive half the dose first and then a full dose. The researchers claim that only three out of thousands of volunteers experienced ‘serious adverse effects possibly related to the vaccine ”, and clarified that all have recovered or are recovering and continue to be part of the trial. In all, 168 people “experienced 175 serious adverse events, but 172 were not related to Covid-19 or control vaccines,” including one case of hemolytic anemia. The transverse myelitis case that was made public in September and that forced the trial to be temporarily halted is considered “possibly related to the vaccine.”
‘Control of the pandemic will only be achieved if the licensing, manufacture and distribution of these vaccines can be achieved on an unprecedented scale and vaccination is extended to vulnerable people,’ said study lead author Professor Andrew Pollard of the University of Oxford, who added: ‘Our findings indicate that the efficacy of our vaccine exceeds the thresholds set by health authorities and may have a potential impact on public health».
Doubts about those over 55
Results from previous trials revealed that this vaccine induces both antibody and T-cell immune responses and is safe in adults 18 years of age and older, including older adults. However, more studies are necessary to know the real scope in people over 55 years of age, since “In general, most of the participants were between 18 and 55 years old”82% specifically, because “people aged 56 and over were recruited later and will be studied in future analyzes of the trial,” the study authors say.
The research team conducted subgroup analyzes to study the difference in efficacy between the two groups: those who received two full doses and those who were vaccinated with only half the vial first, and concluded that regardless of age or time Between doses, there is greater efficacy with the lower first dose formula.
Effective with adenovirus
Professor Sarah Gilbert of Oxford University, who leads the team developing the vaccine and co-author of the study, said that ‘despite the global spread of Covid-19, a large proportion of the population in many countries is not has infected and is not immune ‘, so “Vaccines can play an important role in increasing immunity, preventing serious diseases and reducing the health crisis, so the possibility that more than one effective vaccine will be approved for use in the near future is encouraging. ‘ In fact, the British Minister of Health, Matt Hancock, assured that the Oxford one could be approved in just a few weeks. “We have shown for the first time that a vaccine with adenoviral vectors, a type of vaccine technology that has been used since 2009, is effective and could contribute to the control of the pandemic,” Gilbert said.
Despite the good news, there are still some gaps, such as how long the protection lasts. According to the authors, “more evidence will be needed to determine the duration of protection and the need for additional booster doses of the vaccine” in the future.