Do we need another booster to prevent the antibodies generated by the second dose of the Covid vaccine from decreasing after a few weeks? Even if the phenomenon is expected and this is not the body’s only defense mechanism, the decline could precisely indicate the need for a recall, at least for the most fragile people. This was stated by researchers from University College London in a study published in the journal The Lancet.
The research analyzed the blood of 605 people between the ages of 50 and 70 who had completed vaccination with Pfizer or Astrazeneca. Between three and six weeks after the second dose, the authors write, the antibody level, which varies greatly from person to person, begins to drop, and is much lower after 10 weeks. On average, it goes from 7500 units per milliliter to 3320 for Pfizer, and from 1200 to 190 for Astrazeneca. The phenomenon of the decrease in antibodies, Eleanor Barnes, a hepatologist at the University of Oxford points out to the Guardian, is common to all vaccines, but does not imply that the body’s ability to respond is also lost, also because there are other cells in the system. immune system that can go into action.
“The decrease could suggest a recall strategy, especially at a time when there is a spate of Delta variant cases in Britain. However, even if the level of antibodies decreases, the B and T cells could very well protect against severe disease.