Protection of Pfizer and Astrazeneca vaccines from infection COVID-19 has decreased over time. This was stated in their press release conductive research of the incidence of Coronavirus Zoe Covid Study Scientists from the UK.
In the course of Zoe Covid Study, researchers from the Royal College of London tracks in real time information about four million users of the COVID Symptom Study mobile application users who voluntarily contribute to it the necessary data. Experts analyzed reports of 1.2 million users vaccinated by Pfizer and Astrazeneca preparations from December 2020 to July 2021. They allocated among them those who passed a positive test for Coronavirus, starting in May.
It turned out that if a month after receiving the second dose, the average efficiency of the PFizer vaccine was 88 percent, then after five to six months, this figure fell to 74 percent. If the effectiveness against the contamination of the astrazeneca vaccine contamination in a month was 77 percent, then after four to five months it was 67 percent.
Previously, scientists showed that the effectiveness of the Pfizer / Biontech vaccine six months decreases from 96 to 84 percent. However, the study was conducted when the most common was “alpha” -smm, the British specialists emphasize.