As the US measles outbreak nears 4,000 cases and five deaths amid concerns over vaccine hesitancy, the new CDC director Erica Schwartz says the MMR vaccine is “absolutely safe.”The US has reported 3,887 confirmed measles cases in 2026, with 95% occurring among unvaccinated people or those with unknown vaccination status, according to CDC data as of October 1. The outbreak has also claimed five lives in Pennsylvania, all reportedly among unvaccinated people.As of October 5, Pennsylvania has reported 1,004 measles cases, including 198 hospitalizations and five deaths. Lancaster County alone has recorded 391 cases. The outbreak is the worst recorded in the US since the major measles resurgence between 1989 and 1991.This week, New York Governor Kathy Hochul declared a statewide disaster emergency after the state recorded 108 measles cases through October 3. Of these, 92 cases were reported since July 15 across 18 counties, particularly in under-immunized rural communities.CDC Director Calls MMR Vaccine ‘Absolutely Safe’“If there's one vaccine that parents should be talking to their health care providers about in terms of immunizing their children, the measles, mumps, rubella vaccine is absolutely safe, absolutely effective,” said Erica Schwartz, speaking at the WSJ’s Future of Health event.“We want to make sure that we're constantly telling Americans that the MMR vaccine is safe.”Measles is a highly infectious disease that can be prevented with vaccination. Two doses of the MMR vaccine are recommended for children, while some adults may also need additional doses depending on their vaccination history and risk.Measles was considered eliminated in the US since 2000. However, the country could lose that status as cases continue to rise. The Pan American Health Organization is expected to decide in November whether the US has lost its elimination status.The Trump administration and HHS Secretary Robert F. Kennedy Jr. have faced criticism over their anti-vaccine stance and policies amid the measles resurgence. More recently, President Donald Trump announced a proposal to separate the MMR vaccine into individual shots, which experts have warned could have consequences.Meanwhile, Schwartz attributed the rise in measles infections across the US to declining herd immunity, saying, “the herd immunity within this country and other nations is lower than ever before.”“And so because of that herd immunity, we really want it to be about 95%. I think we're hearing 87% in some communities, 98% in other communities. Because the herd immunity is lower, that's why we're seeing this resurgence of measles.” Schwartz Says Vaccine Hesitancy Is A Global IssueThe recently appointed CDC director also noted that while the US is nearing 4,000 measles cases, there have been more than 45,000 cases of measles in Mexico and Guatemala. She attributed it to global rise in vaccine hesitancy.“So it's not just a United States issue; it's an international issue. And I think the key critical issue is that there is vaccine hesitancy not just within the United States, but we're seeing that vaccine hesitancy throughout the world. Again, my premise is that all happened around COVID, where we were seeing folks who were just not trusting vaccines in general,” Schwartz said.“We were finding that children were not getting vaccinated because they were not going to school during that time frame. So there's a number of reasons why we're seeing this increase in measles,” she said, adding that “people are conflating their concerns about all vaccines; all vaccines are bad.”Schwartz also defended Health Secretary Robert F Kennedy Jr., and said he has always maintained that the MMR vaccine is safe and effective.“I think what people get confused is that the secretary does represent the voices of a number of Americans who are asking the questions about certain vaccines. [...] And so there's this shared decision-making that the secretary is very focused on to say, why aren't we having conversations with parents, with people that may have some concerns about vaccines, rather than saying it's an all-or-nothing premise,” she said.