Study: Fourth vaccine dose, second booster – wanes quickly

On January 2, 2022, Israel began administering a fourth dose of BNT162b2 vaccine to persons 60 years of age or older.  By April 6, 2022 a study found that the fourth dose of the Pfizer-BioNTech COVID-19 vaccine improves protection against infection and severe COVID-19; however, protection against confirmed infection appears to be short-lived.