For a second straight year, health officials, school administrators and parents around the country worry about a previously minimized disease making a comeback. Measles was officially eliminated from the U.S.in 2000, thanks to widespread vaccines and recognition that they worked. But now the potentially deadly disease has roared back, with 1,281 confirmed cases this year in 30 states as of March 5 -- six times higher than the annual average before 2025. Last year, 2,281 cases were reported nationwide. (We're now at 56 percent of that total after just over two months.)

Most patients are unvaccinated youngsters, according to the federal Centers for Disease Control (CDC), which urges parents to protect children with the shot. "We have allowed measles to have a foothold in this country again, which is very unfortunate," said Dr. Tom Frieden, a former CDC director. Though this may seem scary, doctors say vaccinated people face little or no risk. The outbreaks renew attention on the need for early immunization to prevent or minimize the highly contagious virus that causes high fever, rash, cough, runny nose and watery eyes. Symptoms usually disappear after a few weeks, but the disease can cause pneumonia (lung infection). Another less common complication is encephalitis (pronounced en-seff-uh-LIGH-tuhss,) which is brain swelling that can lead to convulsions and leave a child deaf or with intellectual disability.

Vaccination rates have dropped in recent years as activists who dispute the safety of medical injections push to limit immunization requirements in schools. Anti-vaccine groups oppose mandates in more than 20 states, including at least six with current outbreaks. A county in one of those states, South Carolina, has over 990 cases this year – by far the largest U.S. cluster this century. Two children there developed measles encephalitis. Eleven percent of the county's students are unvaccinated because their parents signed exemption forms.

Leaders of the anti-mandate drive include an organization previously led by Robert F. Kennedy Jr., the president's health secretary. His stance on measles shots is that parents should decide after consulting their child's doctor. A spokeswoman at his agency says: "Vaccination remains the most effective way to prevent measles."

Federal official says: "There is no cure for measles, which is why prevention is so critical. The MMR vaccine remains the most reliable and effective way to prevent it." -- Dr. Jay Bhattacharya, CDC acting director

Vaccine mandate opponent says: "This is the most basic human right, the right to decide what we put into and on our bodies. [Medical] data is being used politically and selectively to create a scapegoat for routine infection rates that rise and fall every year." -- Leslie Manookian of the recently formed Medical Freedom Act Coalition, based in Idaho

Doctor says: "We will see more outbreaks. We will see children missing school, parents missing work. . . . That's why we have those immunization laws, because we recognize that your choices impact others." -- Dr Jana Shaw, infectious disease specialist at Upstate Medical Center in Syracuse, N.Y.