The Pennsylvania Department of Health (DoH) reported on Friday that 55 new measles cases had been identified in the state since Wednesday. Officials are continuing efforts to control an outbreak that has affected dozens of counties. In a news release, the DoH confirmed that there have been 890 measles cases in 39 counties this year. The outbreak has led to 173 hospitalizations and four deaths linked to the disease, according to the statement. It also noted that fewer than 1% of the reported cases involved individuals who were vaccinated against measles. Approximately 31% of the cases are among people under the age of 18. In addition to announcing the 55 new cases, the DoH stated that it is “proactively working with residents, community organizations and healthcare providers” to address the outbreak. The department emphasized the importance of providing accurate information and access to the measles, mumps, and rubella (MMR) vaccine. This update came after Robert F. Kennedy Jr., the Trump administration’s health secretary, who is known for skepticism about vaccines, expressed doubts about the deaths linked to measles in Pennsylvania, suggesting they “may even have been altogether fabricated” for political reasons. In August, the new director of the US Centers for Disease Control and Prevention (CDC) ordered staff not to include two measles-related deaths reported by Pennsylvania in the national tally, citing a need to review “additional information.” Lancaster County has recorded the highest number of measles cases in Pennsylvania this year, with 359 confirmed cases. State health officials said that since the outbreak began in late April, more than 5,300 MMR vaccinations have been administered through 165 pop-up clinics in affected areas. Additional clinics are planned based on community interest and need. In total, over 7,900 MMR vaccine doses have been given to residents across the state this year, and healthcare providers have seen a significant increase in people seeking the vaccine. The DoH emphasized that the best way to protect against measles is through full vaccination. The MMR vaccine boosts the immune system and provides 97% lifetime protection. Measles is a highly contagious virus that can lead to serious health complications. Although rare, death from measles occurs in one to three out of every 1,000 cases. The disease was declared eliminated in the US in 2000 but has since resurfaced in communities with lower vaccination rates. According to the CDC, measles spreads through coughing and sneezing, and the virus can remain airborne for up to two hours after an infected person leaves an area. Symptoms typically appear seven to 14 days after infection and include high fever, cough, runny nose, and red, watery eyes, followed by a rash that spreads across the body. The CDC recommends two doses of the MMR vaccine for the best protection. As of 24 September, more than 3,659 confirmed measles cases had been reported in the US this year, compared to 2,289 cases reported nationwide in all of 2025.