The COVID-19 vaccine developed by Oxford / AstraZeneca is 76% effective after the first injection, while that figure increases to 82% after a second inoculated dose after an interval of “12 weeks”, as revealed today by a study published by The Lancet.
In contrast, the preliminary results of a trial conducted by the University of Oxford among 17,178 subjects indicated that the efficacy of this antigen preparation is 55% when the above interval is six weeks.
This suggests that the interval between doses can be safely extended to three months, given the protection offered by a single dose., allowing countries to vaccinate a larger proportion of the population faster, ”the authors explain in a statement.
This work also includes updated estimates regarding the overall efficacy of the covid vaccine in asymptomatic patients, and concludes that it is effective after administration of both doses.
The Oxford vaccine team’s lead investigator Andrew Pollard recalled that, given that the supply of vaccines “will certainly be limited,” at least in the “short term,” authorities will have to decide which immunization schedule to follow. achieve “maximum public health benefits”.
“When supplies are tight, the decision to vaccinate more people with a single dose first may immediately provide more protection to the population, instead of vaccinating half of people with two doses,” Pollard said.
In the long run, he added, the second dose should guarantee “long-term immunity.” and so they have encouraged all those who received the first dose to “make sure they get both doses.”
The study highlights that other vaccines designed to fight Ebola, malaria or the flu, for example, also provide greater protection and boost the immune response when there are “long intervals” between doses.