Measles Spreads to 46 States as Trump Vaccine Overhaul Faces Scrutiny

Iowa is among 46 states reporting measles cases as the nation faces its worst outbreak in over three decades. The surge comes as the Trump administration pushes forward with a controversial plan to split the combined MMR vaccine into three separate shots, a move that has pediatric experts and state health officials concerned.

According to CDC data as of August 13, there are 2,566 confirmed measles cases nationwide, with 38 new outbreaks reported this year. Ninety-four percent of all cases have occurred in people who are unvaccinated or whose vaccination status is unknown.

What Does the Measles Outbreak Mean for Iowa?

Iowa is listed among the states reporting infections, though exact case numbers remain unclear. The state's MMR vaccination rates have been declining for years, mirroring a national trend that public health officials say is leaving more children vulnerable to the highly contagious virus.

Wisconsin, Iowa's neighbor to the east, is reporting between 10 and 49 cases. Health officials say most infections are linked to household clusters and community settings with low vaccination rates.

Why Are Measles Cases Rising Across the Country?

The geographic spread of measles closely tracks declining MMR vaccination rates. Many states have fallen below the 95 percent threshold needed for herd immunity, particularly in regions where vaccine hesitancy has grown and school-entry exemptions have increased.

Wisconsin's immunization registry shows MMR coverage for 24-month-olds fell from 84.9 percent in 2019 to 79.8 percent in 2025. Coverage among 6-year-olds also slipped from 81.6 percent to 75.3 percent over the same period. Some Wisconsin counties, including Clark, Monroe, Vernon, and Crawford, have rates dipping below 70 percent.

Public health officials point to several factors driving the decline:

• Lower routine pediatric visit rates during and after COVID-19
• Growing vaccine hesitancy, amplified by misinformation
• Local pockets of low coverage, even in counties with high statewide averages
• Increased global measles activity, raising importation risk

What Is the Trump Administration's New Vaccine Plan?

President Donald Trump signed an executive order directing HHS to split the MMR vaccine into three separate shots once manufacturers can produce them domestically. The order also encourages spacing out all childhood vaccines into separate appointments to the maximum extent feasible.

The plan moves several vaccines, including RSV monoclonal antibodies, hepatitis A and B, and meningococcal vaccines, into a high-risk category, narrowing routine access. It also instructs states to review school-entry immunization laws and consider updates aligned with the new federal recommendations.

Pediatric experts have raised concerns about the approach. Dr. Melissa Stockwell, Division Chief of Child and Adolescent Health at Columbia University, told Newsweek that splitting the MMR shot adds unnecessary burden for families and raises the risk of missed and delayed doses, leaving children unprotected for longer.

Dr. Patsy Stinchfield, Executive Director of the Measles Collaborative, noted that the combined MMR shot has been safely used since 1971 and that more than 99 percent of people who receive two doses after their first birthday develop protective antibodies. She called the plan to divide the shot not an evidence-based recommendation.

Are Individual MMR Shots Available Now?

Despite the administration's directive, single-antigen measles, mumps, and rubella vaccines are not currently available in the United States. Manufacturers have not announced plans to produce them, and pediatric experts say there is little incentive to create separate products.

The CDC's vaccine schedule has not changed since the executive order. The agency continues to recommend the combined MMR shot at 12-15 months and 4-6 years. CDC officials say they are reviewing the order and awaiting HHS guidance.

State health departments, including Wisconsin DHS, continue to advise families to follow the existing CDC schedule, citing the ongoing outbreak and the high effectiveness of the combined MMR vaccine.

What Should Iowa Families Do Now?

Health officials recommend that Iowa families follow the current CDC schedule and ensure children receive the combined MMR vaccine on time. Measles is one of the most contagious viruses on earth, and the CDC reports that 93 percent of cases this year occurred in people who were unvaccinated or whose vaccination status was unknown.

Sen. Bill Cassidy, a Louisiana Republican and physician, criticized the executive order, saying the president does not have the expertise to make these changes and warning that splitting the MMR shot would increase hesitancy and leave children exposed longer.

The Partnership to Fight Infectious Disease warned that rewriting vaccine guidance during the largest measles resurgence in decades will only leave more American children vulnerable to preventable illness.

Newsweek has reached out to the White House for comment on the ongoing situation.