In a statement on Saturday, the headquarters said that only those who have received at least one COVID-19 booster shot can travel to Iraq for the annual Arbaeen march.
It added that all of those willing to take part in the spiritual journey are required to register their names on a special website named Samah.
The statement noted that there will be a process of coronavirus vaccination and those who do not meet the vaccination conditions will not be able to make the trip.
The Arbaeen mourning ceremony is one of the largest religious gatherings in the world.
It marks the 40th day after Ashura, the martyrdom anniversary of the grandson of Prophet Mohammad (PBUH), Imam Hussein (AS). This year’s Arbaeen falls on September 17.
Each year, a huge crowd of Shias flock to Karbala, where the holy shrine of Imam Hussein (AS) is located, to perform mourning rites.
The pilgrims, mainly from Iraq and Iran, travel long routes on foot to the holy city.
The Arbaeen march was held with the participation of a limited number of pilgrims, mostly Iraqis, in the past two years due to the COVID-19 pandemic.