A new study suggests a fourth dose of the Pfizer COVID-19 vaccine may have only marginal benefits for the young and healthy. 

Research from the Sheba Medical Center Tel Hashomer in Israel has found that a fourth dose of the Pfizer COVID-19 vaccine can restore antibody levels to the peak seen after the third booster dose.

However, the fourth jab does not appear to boost antibody levels any further. 

The study covered healthy young health care workers who were given a fourth dose around 4 months after their third dose booster. 

The data showed that while it restored antibody levels to the previous peak, it didn't really push them any higher, suggesting that our maximum immune response is seen after three doses. The authors say a fourth vaccination may have only marginal benefits in this population. 

The study is accessible here.