Pfizer asks US to allow 4th COVID vaccine dose for seniors

Prepared Pfizer COVID-19 vaccine syringes wait for patients at a middle school in Wheeling, Ill., June 11, 2021. Drugmaker Pfizer is expected to request authorization this week for an additional COVID-19 booster dose for seniors. That, according to a person familiar with the matter, who spoke on condition of anonymity. (AP Photo/Nam Y. Huh, File)