So far, 1,574,982 people have received the third shot, also known as the booster.
Meanwhile, Iranian Health Ministry figures released on Tuesday show 79 people have died from Covid-19 over the past 24 hours.
The total death toll from the disease in Iran since the start of the pandemic that engulfed the whole world is 130,356.
Two cities in Iran are marked red, which means the risk of Covid is very high there. 9 cities are orange, 153 yellow and 284 blue. Blue cities are where people face the lowest level of risk from Covid.
A range of factors helped maintain the downward trend in Covid deaths and infections in Iran including a fast vaccination drive across the country, unrelenting efforts by the government and people’s help with the inoculation process.
The vast majority of people in Iran have welcomed the vaccination campaign.
Iranian authorities have relaxed some curbs put in place to contain Covid. But they urge people to be cautious as a sixth wave of the outbreak is still a possibility.