Sheba researchers observed a decline in immunity a few months after receiving the second dose of Pfizer-BioNTech’s COVID-19 vaccination in a study published by the New England Journal of Medicine.
In a recent study, Sheba monitored 5,000 healthcare professionals for six months after receiving the second dose of the Pfizer-BioNTech COVID-19 vaccine. The findings were published in The New England Journal of Medicine, one of the world’s foremost medical journals.
The study indicated a significant and continuous decrease in IgG antibodies and neutralizing antibodies, which seem more important in preventing illness. The reduction in neutralizing antibodies happened rapidly at first, and then slowed down after two or three months.
Based on data gathered during the study, researchers created a model that predicts the expected level of antibodies in different population groups, such as men, women, and overweight individuals.
“We developed a model that shows the probability of different populations exhibiting different antibody levels,” explained Prof. Gili Regev-Yochay, Head of the Infection Prevention and Control Units at Sheba, who also led the study. Prof. Regev-Yochay added: “In the future, using this model, we will be able to estimate the likelihood of severe or mild illness among different population groups and determine the best treatment course accordingly.”
According to Prof. Gili Regev-Yochay: “The world is trying to identify the critical threshold value of antibodies to prevent infection, illness, and mortality. Identifying the thresholds for different populations, as we did in this study, will enable us to assess the risk for each group and determine whether a booster shot or non-pharmacological means such as self-isolation is needed.”
As for the future of the study, Prof. Regev-Yochay says: “We have already started the next phase, which involves monitoring antibody levels after the booster shot. This data is expected to be a significant part of the decision-making process concerning future vaccination policies.”