With the number of confirmed measles cases in Texas growing and the first death in the outbreak reported Wednesday, New York's Department of Health on Thursday issued a health advisory.

New York officials also warned of statewide vaccination rates being below a level "necessary to protect communities," urging New Yorkers to vaccinate their children against measles.

"Measles is a very contagious, serious respiratory disease that causes rash and fever. In some cases, measles can reduce the immune system’s ability to fight other infections like pneumonia," said Dr. James McDonald, the state health commissioner, in a statement. "I encourage anyone not vaccinated against measles to receive at least one dose of the Measles, Mumps and Rubella (MMR) vaccine and get their children vaccinated with two doses."

The state's health advisory also pointed to increased measles cases and hospitalizations in Canada as part of the reasoning for the advisory itself. The advisory indicates 44 reported cases in Canada this year already — 31 in Ontario and 13 in Quebec.

In Texas, the death of an unvaccinated school-aged child Tuesday night marked the first U.S. death from the highly contagious respiratory disease since 2015.

"These tragedies can be prevented and they need to be prevented," said McDonald.

According to Dr. Jennifer Nayak, a pediatric infectious disease specialist with University of Rochester Medical Center, in unvaccinated communities, one person infected will infect 12 to 18 others.

"Having a death is unusual, but unfortunately, measles is a very bad, very scary disease," said Nayak. "There's a reason that we vaccinate against it. That's an attack rate of about 90%. But vaccination rates, kind of overall and especially in certain areas, are going down, which is leaving the population susceptible to this."

In New York state, the vaccination rate is 81%. But in certain counties, the rates are much lower.

In Yates, it's just under 56%; in Jefferson County, a little over 57%. Yates is among the New York counties with the lowest populations.

While some states, including Texas, allow for religious exemptions, New York state schools mandate children to be vaccinated.

"There's a lot of reasons why people are hesitant about vaccines," said McDonald. "Some of them are steeped in culture, but too many of them are steeped in misinformation. it's important to understand that when people are getting misinformation. My only agenda is to keep you healthy. I have nothing to sell you. People who are spreading misinformation don't have your best interests at heart."

Nayak and McDonald want to remind the community, the measles vaccine has been extensively studied and shown to be safe and effective.

"It's something you're doing it to help yourself," said Nayak. "You're doing it to help your family and your loved ones, but you're also doing it to help the people who can't respond."