More people in the US have been infected with the measles so far in 2019 than any year since the disease was considered eliminated, officials announced Wednesday.
The Centers for Disease Control confirmed that 695 cases of measles have been reported in 22 states. Local officials in New York, where an outbreak has spread to hundreds, have said most of the cases are of young children who have not been vaccinated. Two of the recent cases in New York are pregnant women, who are now at risk of miscarriage.
The outbreaks have been driven by misinformation about the safety of vaccines, the CDC said, and in New York, officials have been fighting to stop new cases since last October.
"The longer these outbreaks continue, the greater the chance measles will again get a sustained foothold in the United States," a CDC press release said.
Before the measles vaccination program was established in 1963, between 3 and 4 million people would become infected with the highly contagious disease each year. Between 400 and 500 of them died.
But vaccination, which typically comes in the form of two shots before the age of 6, has been safe and effective, CDC officials said. In 2000, only 86 cases were reported, and measles was considered formally eliminated from the US.
But as pockets of people around the US have refused to vaccinate their children, measles — considered one of the most preventable diseases — has made a comeback. Several recent outbreaks have been sparked by travel of an unvaccinated person to a country where the disease is still prevalent. When they've returned home to the US, the measles virus has quickly spread through communities of unvaccinated people.
The last serious outbreak took place in the US in 2014, when 667 cases of measles were reported. Experts believe outbreaks will become the new normal, which will put vulnerable people who can't be vaccinated — including infants and people with compromised immune systems — at increased risk.
Anti-vaccination campaigns are driven by misinformation, such as the repeatedly debunked claim that vaccines cause autism. President Trump has tweeted multiple times that he believes the current vaccine schedule for children causes autism; the CDC recommends its schedule to ensure children are protected when they are most vulnerable to disease, according to a guide for parents.
For months, the Trump administration had been silent on the current outbreaks. On Wednesday, Health and Human Services Secretary Alex Azar urged Americans to get vaccinated and emphasized that measles is highly contagious and potentially deadly.
"The measles vaccines are among the most extensively studied medical products we have, and their safety has been firmly established over many years in some of the largest vaccine studies ever undertaken," he said. "With a safe and effective vaccine that protects against measles, the suffering we are seeing is avoidable."