
An Israel-based study has found that a fourth dose of the Pfizer Inc (NYSE:PFE) / BioNTech SE (NASDAQ:BNTX) vaccine lowered rates of COVID-19 infection among the elderly. However, the protection against disease appeared to be short-lived.
Israeli researchers showed that the second booster's protection against infection dwindled after four weeks in their study published in the New England Journal of Medicine.