The claim that Vatican City has no Muslims is not entirely accurate but can be understood in context. Vatican City, the smallest independent state in the world, is the spiritual and administrative center of the Roman Catholic Church. As such, it has a very small population, primarily composed of clergy, church officials, and the swiss Guard, who are responsible for the security of the Pope. The permanent residents are mostly Catholic, given the nature of the Vatican’s religious role.
While Vatican City might not have any permanent Muslim residents, this does not mean that Muslims are banned or cannot visit. The Vatican receives millions of tourists every year, including Muslims, who visit to see its religious and historical sites, such as St. Peter’s Basilica and the Sistine Chapel.
The idea that there are no Muslims in Vatican City likely stems from the fact that its permanent population is so small and predominantly Catholic, reflecting the city's unique role as the heart of Catholicism. However, in a broader sense, Muslims, like people of other faiths, can and do visit Vatican City as tourists or on diplomatic missions. Vatican city is a holy place for Christians just like Mecca is for Muslims.