Health officials warn that without increased vaccination efforts, the U.S. risks measles becoming endemic again.

As of early May 2025, the U.S. has reported 683 confirmed measles cases since January, with the majority occurring in west Texas, and additional cases in New Mexico, Oklahoma, and Kansas, resulting in three deaths, including two unvaccinated school-aged children.

Experts attribute these outbreaks to declining vaccination rates, which compromise herd immunity when coverage falls below 95%.

Vaccine hesitancy, driven by misinformation and insufficient public health promotion, is a significant factor in the declining vaccination rates, according to health advocates.

Federal public health funding has been cut by $11 billion, severely impacting local vaccination efforts and prompting lawsuits from various governments, including Metro Nashville and Harris County, Texas.

In Louisiana, the vaccination rate for kindergarteners is only 91%, leaving many children vulnerable to outbreaks similar to those seen in Texas.

Michigan has confirmed nine cases of measles, some of which are linked to an outbreak in Ontario.

Dr. Conrad Fischer, an infectious disease expert, expresses concern over the resurgence of measles, a disease that was nearly eradicated in the U.S. before this recent spike.

Vaccination remains the primary prevention method, having drastically reduced measles cases since its introduction in 1963, with the vaccine showing about 93% effectiveness after the first dose and 97% after the second.

The current outbreak has affected various age groups, with 285 cases in children under five, 353 in those aged five to 19, and 284 in adults aged 20 and older.

Local health officials cite barriers such as vaccine hesitancy, misinformation, and access to healthcare, exacerbated by the COVID-19 pandemic, as significant challenges in improving vaccination rates.

Individuals born between 1968 and 1989 may need an additional MMR vaccine dose, as the two-dose recommendation was established only in 1989.