As national cases of measles soar and federal health officials engage in vaccine skepticism, Illinois so far this year has seen only one small outbreak of the highly infectious disease that health officials say was quickly brought under control.

In April and May, eight people in southern Illinois, “all linked to one another,” contracted measles, the Illinois Department of Public Health said Friday. But with no new cases identified since May 22, enough time has now passed to consider the outbreak over, the state said.

As of this week, more than 1,200 measles cases had been confirmed nationwide this year, according to the Centers for Disease Control and Prevention, the highest annual number since the disease was officially declared eliminated in 2000. Three people with measles, including two children, have died.

“In Illinois, we’re relieved to tell a much different story,” Dr. Sameer Vohra, director of IDPH, said at a news conference Friday in Springfield.

Of eight people in the downstate outbreak, none fell seriously ill, Vohra said. Also this spring, health officials identified two unrelated measles cases in Cook County but didn’t see indication of additional spread, IDPH said.

Officials identified the first case downstate this year in an unvaccinated adult in Marion, near the southern tip of Illinois. All of the state’s cases this year have been adults, Dr. Jennifer Seo, an adviser in pediatric medicine at IDPH, said.

IDPH declined to release additional demographic information about those who contracted measles, citing medical privacy rules.

Local departments including the Franklin-Williamson Bi-County Health Department and Jackson County Health Department held vaccine outreach clinics to contain the spread in those areas, IDPH said. Local officials went business to business to offer vaccinations, and the state health department also held mobile vaccination clinics, IDPH officials said.

Amid those efforts, more than twice as many individuals in Franklin, Williamson and Jackson counties received vaccinations each month compared with January, Seo said. All three counties already had high vaccination rates above 96% in schools, which helped contain the spread, she said.

State officials took quick action downstate this year after seeing a much larger outbreak in Chicago last year, Vohra said. That outbreak, which rose to 64 cases, primarily affected migrants in a shelter on the Lower West Side, according to a report from the city’s Department of Public Health.

Measles spreads through the air or when a person comes into contact with an infected person’s mucus or saliva, according to state public health information. It is particularly dangerous to babies and young children.

In March 2024 public health officials identified the first case of measles in the city since 2019 on the Northwest Side. The next day, officials reported the first positive case in the migrant shelter, where nearly 2,500 people lived in close quarters. Vaccination rates in the U.S. have dropped since the COVID-19 pandemic, according to IDPH.

As recently as this spring, U.S. Health and Human Services Secretary Robert F. Kennedy Jr. said the measles vaccine causes “adverse events” and suggested its effectiveness wanes quickly, Associated Press reported.

The CDC says the vaccine is safe and effective.

All three people in the U.S. that died with measles this year were unvaccinated. Before this year, there had not been a measles death in the U.S. for a decade.

Two doses of the measles, mumps and rubella vaccine are considered 97% protective against the measles, and one dose is considered 93% protective, according to the CDC. Children typically receive the first dose of the vaccine, or the similar measles, mumps, rubella and varicella (chickenpox) vaccine at age 12 to 15 months, and the second dose from ages 4 to 6.

Even before the beginning of the downstate outbreak, health officials targeted communications about disease prevention to ZIP codes with low school vaccination rates and saw an uptick in vaccination as early as March, Seo said.

With cases still relatively high across the country, the state public health department remains vigilant, said Vohra, who is also a pediatrician.

“It could return here, possibly quickly,” he said.