Sen. Ron Johnson (R-WI) is demanding answers from the Centers for Disease Control and Prevention after the agency told a nonprofit group that it never conducted a mandated data mining analysis on reported adverse effects that followed the administration of COVID-19 vaccine doses.

The CDC is tasked with performing a proportional reporting ratio, or PRR, data mining analysis on a weekly basis to determine whether the amount of reported “adverse events” following the administration of COVID-19 vaccine doses in the public Vaccine Adverse Event Reporting System, or VAERS, database is proportional to reported adverse events linked to the administration of other vaccines.