A measles alert has been issued in New Jersey after three cases of the highly contagious virus were confirmed in the state’s most populous county.

A person who did not receive the measles vaccine in Bergen County got infected with the virus after coming back from a trip abroad. This individual passed on the virus to two other unvaccinated individuals, as reported by the New Jersey Department of Health.

The state health department issued a warning on Thursday following the confirmation of a measles-related death in Texas. The deceased was an unvaccinated child, making it the first measles fatality in the United States since 2015.

Individuals who were at Englewood Hospital’s emergency department between 11:30 a.m. and 5:30 p.m. on Feb. 9 are advised by NJDOH to watch out for symptoms, which may show up as late as March 6, according to the health department.

The department is also working to contact trace anyone else who might have been exposed but emphasized that any patient, staffer or visitor who was at the hospital between those hours should contact their healthcare provider immediately.

Those who suspect they might have been exposed should first call their doctor before heading to a facility so that they don’t risk infecting more people.

New Jersey’s alert comes after an outbreak swept through Texas, infecting 146 and counting with 20 hospitalized and a child dead, according to the Texas Department of State Health Services.

Another measles case was also confirmed in an unvaccinated child in Montgomery County, Pa. on Sunday, according to the Montgomery County Department of Health.

The measles spread has pushed many to highlight the importance of lifesaving vaccines like the MMR. Many have called on Robert F Kennedy Jr. — the newly confirmed United States Secretary of Health and Human Services who has infamously come out against vaccines — to speak on the outbreak and visit the communities most affected to try and sway the needle.

Kennedy has largely downplayed the Texas outbreak — largely confined to a close-knit religious community with low vaccination numbers — saying measles cases were “not unusual.”

Measles was all but eradicated from the US as of 2000 after a decades-long vaccination campaign. New cases now only pop up in the country when contracted abroad, according to the CDC.

Kindergarteners entering public schools nationwide are required to be vaccinated for measles – but since the COVID-19 pandemic, most states’ kindergarten-aged populations have dropped below the 95% vaccination threshold considered vital for stopping measles outbreaks.

A majority of those in the Northeast are vaccinated, but there’s been a slight downward trend.

More than 93% of New Jersey kindergarteners received the MMR vaccine last year, but the percentage was still down one percent from just over 94% in 2022, according to the Centers for Disease Control and Prevention. More than 97% were vaccinated in New York and Connecticut in both years.

Federal MMR vaccination rates meanwhile fell by about 2.5% from 2020 to 2024, according to the CDC.

Measles is a highly contagious airborne disease. Bacteria can remain in the air for up to two hours after anyone who has contracted it coughs or sneezes, according to the NJDOH.

Symptoms include high fever, cough, runny nose, watery red eyes and a rash that usually appears between three and five days after symptoms begin.

Those most at risk are people not fully vaccinated or who have not had the measles before. The MMR vaccine is two doses and typically provides lifelong protection against the disease.