The World Health Organization and Pan American Health Organization have jointly declared the Americas free of measles.
Measles is one of the most contagious diseases and primarily affects children, causing severe health problems including pneumonia, blindness, brain swelling and even death.
For the past 22 years governments and organisations across the Americas - comprising the entirety of North and South America, Latin America and the Caribbean - have been conducting mass vaccinations against measles, mumps and rubella.
PAHO/WHO Director Carissa F. Etienne said its elimination is an historic event for the region and the world.
"It is proof of the remarkable success that can be achieved when countries work together in solidarity towards a common goal. It is the result of a commitment made more than two decades ago, in 1994, when the countries of the Americas pledged to end measles circulation by the turn of the 21st century," he said.
Measles is the fifth vaccine-preventable disease to be eliminated from the Americas, after the regional eradication of smallpox in 1971, poliomyelitis in 1994, and rubella and congenital rubella syndrome in 2015.
The ruling on its elimination was made following its declaration as 'interrupted' since 2002, when the last endemic case was reported in the region. However, the WHO said some countries in the Americas experienced imported cases because the disease had continued to circulate in other parts of the world.
A panel of international experts reviewed evidence on measles elimination presented by all the countries in the Americas between 2015 and August 2016 and decided that it met the established criteria for elimination.
The process included six years of work to document evidence of the elimination.
In 2015 there were 244,704 measles cases reported worldwide, representing a significant decline from earlier years, which the WHO attributes to global immunisation efforts.
Western Australia's most recent outbreak of measles was in July when backpackers staying in Northbridge were diagnosed.
A controversy over MMR vaccines in the UK in the late 1990s has given rise to a so-called anti-vaxxer movement, which opposes immunisation against measles and other diseases.
But Ms Etienne said the elimination of measles in the Americas showed that vaccination is hugely important and must be maintained.
"I would like to emphasise that our work on this front is not yet done. We can not become complacent with this achievement but must rather protect it carefully. Measles still circulates widely in other parts of the world, and so we must be prepared to respond to imported cases.
"It is critical that we continue to maintain high vaccination coverage rates, and it is crucial that any suspected measles cases be immediately reported to the authorities for rapid follow-up."