The preliminary results of the third phase of the clinical trial showed an average efficacy of 70.4%, depending on the dose used, with a maximum of 90%. A reduction in asymptomatic infections was also observed. There were no serious cases or hospitalizations among the vaccinators. Storage between 2 and 8ºC in the refrigerator would be an advantage.
Following the preliminary results of Pfizer and Moderna, the results of the Oxford/AstraZeneca vaccine were obtained.In this case, depending on the dose used, the efficacy reaches 90%, because Ensure press release.The number of volunteers infected with covid-19 is 131.The person in charge guarantees that their vaccine will also work Reduce spread Coronavirus.
The preliminary results correspond to an independent analysis of the data obtained on November 4. These indicate that the efficacy of the vaccine is 70.4%, which varies according to the dose used. If both are completed, the percentage drops to 62%. If the first dose is halved, the figure rises to 90%.
Some researchers think these Counterintuitive result And it is worthy of further study. Ian Jones, a researcher at the University of Reading, conducted a theoretical analysis of the researchers: “The reduced efficacy of two full doses of the drug may be related to the increased immunity against the carrier, but we will have to wait for the publication Data to determine whether this is the case.” In the statement of the Science Media Center.
According to Stephen Griffin, a researcher at the University of Leeds, “it would be easy to solve if an adjusted dose is used” and “it has nothing to do with safety”. In any case, it is not known whether receiving a lower dose will affect the duration and quality of protection received. The 90% power obtained in this subgroup of 3,000 participants is also not statistically convincing.
The Oxford/AstraZeneca team has not disclosed the number of infections that have calculated these numbers, but they hope to get more cases before final analysis.He also made sure that future research will determine Protection period And no serious safety problems were found. The latter is very important if we consider that the trial has to be stopped in September due to possible adverse reactions. After a few days, it was discarded.
In addition, they believe that the most effective regimen (half-dose first and then full-dose) can help prevent the spread of the virus because the incidence of asymptomatic infection is lower in the vaccinated population. They added that they will reveal more information in this regard in the next assessment.
The analysis of these data is based on the results published in Phase I/II last week Lancet. They showed that the vaccine can induce a strong immune response in all age groups (including people over 70) and is safe. In addition, the team also ensures that the complete analysis is submitted to peer review for publication, while sharing data with all regulatory agencies around the world for future approval.
Efficacy is not the same
The Oxford/AstraZeneca clinical trial has more than 24,000 participants from the United Kingdom, Brazil and South Africa, and is currently moving towards the final analysis.The United States, Kenya, Japan, and India are conducting trials, and the research team hopes to achieve 60,000 volunteers Before the end of the year. They hope to use these numbers to provide regulators with more information about the efficacy and safety of the product and its ability to protect and stop the spread of the coronavirus.
As with Moderna and Pfizer vaccines, it should be remembered that the efficacy of these products under ideal clinical trial conditions is different from the efficacy shown after large-scale use under real conditions.
“People will be tempted Compare the efficiency between vaccinesBut we must remember that this is preliminary data intended to be approved. Efficacy and efficacy are not the same. With the introduction of vaccines, the initial number will change.
In this sense, Azra Ghani, a researcher at Imperial College London, believes that it is important to point out that the difference in efficacy observed between Pfizer, Moderna and Oxford University may be due to the fact that the first two people started recruiting volunteers at the end of July. British universities start in May.
Adenovirus and ARNm
Pfizer and Moderna vaccines use a new technology based on messenger RNA, while the Oxford University vaccine is made of Attenuated version of adenovirus, Is one of the people who cause the common cold. It has been modified so that it cannot grow in humans.
These types of vaccines have been studied and used for decades, which is why people know that they are stable, easy to produce, transport and store. In fact, they can be stored between the refrigerator temperature (2 to 8ºC).Oxford/Astrazeneca officials believe that this will make distribution from medical centers to pharmacies easier, and Competitive advantages Compared with Pfizer and Moderna, which require temperatures of -70ºC and -20ºC, respectively.
“[La vacuna de Oxford] It is better than the other two in the following aspects distribution. Ivor Ali, a researcher at the University of Warwick, said that more flexible storage conditions will reduce wasted vaccines due to cold chain failures, which are unavoidable for mRNA. “This will also allow us to use our vaccine distribution infrastructure without adjustments, which is particularly suitable for developing regions due to its lower cost and simpler logistics.”
Oxford/AstraZeneca has ensured that vaccines are already being produced in ten countries to ensure equitable access to global vaccines and reached an agreement to produce 3 billion doses of vaccines.