Not all vaccines, it has become clear, are created equal. In May 2021, a study published in Nature Medicine made this claim based on the aggregated clinical trial results of seven different Covid-19 vaccines. Using predictive modeling techniques to plot the strength and duration of their immune protection over a theoretical timeline of 250 days, the study’s authors showed that some vaccines dropped to 50 percent efficacy much earlier than others. Leading the pack were Pfizer and Moderna’s mRNA vaccines, which performed at 95 percent efficacy initially and took a full 250 days to fall to 50 percent. The AstraZeneca vaccine rounded out the bottom with 62 percent initial efficacy and a half life of 48 days, though the Sinopharm vaccine fared even worse, having just 50 percent efficacy to begin with.
Did any poster here who has had AZ in the last few months know that it was only 50% effective after 48 days?