Lancaster County in Pennsylvania has been the epicenter of the nation's worst measles outbreak in 35 years. It's also home to the largest Amish population in the U.S. Some Amish and related Mennonite groups, with historically lower rates of vaccination, have been hit hard. Vaccination rates also declined in the general population amid the resurgence of a contagious virus considered “eliminated” from the U.S. since 2000. Pennsylvania leads the U.S. this year with over 1,350 cases, more than a third in Lancaster County, according to official figures. Many Amish and Mennonites are showing a new openness to vaccines, while members of the general public are also taking extra precautions.

A first-of-its-kind cancer vaccine is helping significantly reduce the chances that melanoma patients' tumors return. Drugmakers Moderna and Merck announced the results Thursday. The vaccine was custom-brewed for each patient to match their tumor. It teaches the patient’s immune system to watch out for and attack any cancer cells that start forming again. Adding it to a standard post-surgery treatment reduced by 42% the risk of melanoma returning two years after surgery, according to the most advanced study to date.

Many American scientists are being recruited by foreign universities holding out offers of stable funding and academic freedom. It began last year after the Trump administration began making seismic changes to U.S. scientific research. Administration actions included canceling hundreds of federal grants and deprioritizing research on topics including climate change and vaccination. Foreign universities saw an opportunity. According to a report, 21 countries have programs to attract U.S. researchers. Since then, many have taken the bait. While there is no way to quantify the overall change in the academic landscape, scientists and professional groups say the shift is clear and concerning.

Pennsylvania has more than 1,000 measles cases this year, making it the largest state outbreak in decades. Since the beginning of last year, large outbreaks have been reported in several states. South Carolina had the largest, with 997 cases reported. Pennsylvania health officials say the state's current outbreak started in April, west of Philadelphia, and has led to five deaths. Large outbreaks have also been reported in Texas and Utah.