At least 124 cases of measles have been identified in Texas since late January, mostly among children and teenagers who are either unvaccinated or whose vaccination status is unknown, officials say.

LUBBOCK — A person who was hospitalized with measles has died from measles in West Texas, the first death in an outbreak that began late last month. Texas Tech University Health Sciences Center spokesperson Melissa Whitfield confirmed the death Wednesday. It wasn’t clear the age of the patient, who died overnight.

The effectiveness of the vaccine, coupled with rising vaccination rates, led to such low rates of measles that it was declared eliminated in the U.S. in 2000. In recent years, though, the virus has made a resurgence, as childhood vaccination rates have dropped nationwide.