Avinu Malkeinu is a prayer consisting of a series of supplications to G-d that is usually said only on fast days and during the Ten Days of Repentance that are marked between the Rosh Hashana and Yom Kippur holidays.
"We are going through difficult days, and even doctors aren't finding a cure or medicine and understand that we have nothing to rely on but our Father in Heaven," wrote Lau in a letter to Kanievsky, Rabbi Shalom Cohen and Rabbi Gershon Edelstein. "Therefore, I ask for direction whether the congregation should say the Avinu Malkeinu prayer in these days and especially to yell the statement 'Our Father, Our King, withhold the plague from Your inheritance.'"
Kanievsky added that this is a "correct thing" to do. Cohen and Edelstein agreed that the practice should be implemented.
The rabbis called on all synagogues to begin reciting the prayer after the cantor's repetition of the Shemonah Esrei prayer in the morning and afternoon prayers.