On April 9, the state of New York declared a public health emergency. The reason for this, as CNN pointed out, was the measles outbreak affecting the Orthodox Jewish community in Williamsburg. The outbreak began in October, however, and measles outbreaks have since been reported in 19 American states.

Caused by a virus, measles — or rubeola — can be serious, proving fatal for some individuals. Inflamed eyes, fever, dry cough, and skin rashes are common symptoms of this highly-contagious, infectious disease, per the Mayo Clinic. Measles is an entirely preventable disease, however.

Causing the global resurgence of the disease is a decline in vaccination, according to new National Institutes of Health research. The research claims that — unless there is collective action, and a new focus on vaccination efforts — the disease could rebound in full force.

Published in The New England Journal of Medicine, “Measles in 2019 — Going Backward” examines the recent resurgence of measles, as well as its causes. The article recommends solutions meant to curb the outbreak and to prevent the disease from rebounding. Measles could erupt into a serious problem if the existing trends continue.

In the year 2000 — researchers Catharine I. Paules, Hilary D. Marston, and Anthony S. Fauci write — measles was declared to be completely eliminated in the United States.

The disease was eliminated, according to the researchers, because of an organized effort by families and healthcare practitioners. The widespread immunization which eliminated the disease in America was, however, short-lived. Now, measles is spreading throughout under-vaccinated populations. This pattern is seen not only in the United States, but across the world.

#BREAKING: Washington state Senate votes to ban personal, philosophical vaccine exemptions amid measles outbreak https://t.co/pW0tvSDZDi pic.twitter.com/s9NTtC6oGQ — The Hill (@thehill) April 18, 2019

A safe, highly-effective vaccine which fully prevents measles is available — so why is there an outbreak? According to the researchers, the resurgence of the measles is due to misconceptions about vaccination, which largely stem from debunked claims propagated by a growing anti-vaccination movement. Anti-vaccination advocates are able to deliver their message through friendly media channels.

This is why a full-blown rebound of the disease is looming over the United States, per the researchers, in addition to other countries across the globe.

“If we continue to lose ground on measles prevention through vaccination, we face the reemergence of measles into new populations, which will pose new and varied challenges.”

This outcome can only be prevented by collective action, according to the scientists. They describe the recent resurgence of the disease as an “alarming step backward.”

“If this trend is not reversed, measles may rebound in full force in both the United States and other countries and regions where it had been eliminated. Promoting measles vaccination is a societal responsibility, with the ultimate goal of global elimination and eradication — relegating measles to the history books,” they wrote.