U.S. Measles Cases Soar to 4,588 Amid Federal Vaccine Policy Changes

The United States is experiencing a major measles surge in 2026, with 4,588 confirmed cases reported across 45 states and the District of Columbia as of October 22, a substantial increase from 2,289 cases in 2025[11][14][21]. This health crisis coincides with Robert F. Kennedy Jr.'s tenure as the 26th United States Secretary of Health and Human Services (HHS), a role he has held since 2025[15][17].

This rising number of measles cases, coupled with significant changes in national vaccine policy under Secretary Kennedy, generates concern among public health organizations and could affect immunization access and contribute to health disparities across the country.

What the records show

Official reports indicate 4,588 measles cases in the U.S. as of October 22, 2026, a 4% increase from the previous week's 4,410 cases, and a sharp rise from 2,289 cases in 2025[11][14][21]. Major outbreaks have been reported in states such as Pennsylvania and Texas[12][24].

Since becoming HHS Secretary in 2025, Robert F. Kennedy Jr. has enacted significant changes to U.S. vaccine policy[1][3][15][17]. A July 2026 Reuters report detailed efforts to dismantle long-standing policy, including allocating billions to investigate a possible link between vaccines and autism, elevating vaccine skeptics within the administration, and attempting to eliminate the federal childhood immunization schedule[1][22]. Kennedy's department also halted over half a billion dollars in federal funding for mRNA vaccine research in August 2025[29]. In November 2025, the Centers for Disease Control and Prevention (CDC) updated its website, removing a statement that studies showed no link between vaccines and autism. The updated language states that studies "have not definitively ruled out the possibility of a link"[30].

One significant change occurred in June 2025 when Secretary Kennedy reportedly fired all 17 members of the Advisory Committee on Immunization Practices (ACIP) and replaced them with new appointees, many of whom had little or no experience with vaccines[9]. Although the CDC renewed ACIP's charter in April 2026, more than 130 organizations expressed deep concern that the revised charter could undermine confidence in vaccines and affect access to immunizations[6][7]. The Pediatric Infectious Diseases Society (PIDS) warned in June 2026 that changes to ACIP's focus, membership, and governance could lead to confusion and delays, threatening public access to vaccines and evidence-based information[8]. In January 2026, the CDC announced an overhaul of the childhood immunization schedule, reducing the number of targeted diseases from 17 to 11[23]. However, a federal judge blocked the implementation of these changes and the ACIP appointments, maintaining the pre-existing CDC schedule[10]. President Trump also issued an executive order in August 2026 to “break up the vaccine schedule into more doses,” which FactCheck.org characterized as containing “false and misleading claims” about the U.S. childhood vaccine schedule[5][19]. These actions by HHS did not uphold promises Kennedy made to senators during his confirmation regarding his stance on vaccines[16][27].

The timeline

• 2025: Robert F. Kennedy Jr. becomes the 26th U.S. Secretary of Health and Human Services[15][17]. In June, he reportedly fired all 17 ACIP members[9]. In August, Kennedy halted over half a billion dollars in federal funding for mRNA vaccine research[29]. The CDC website updated its statement on the vaccine-autism link in November[30].
• January 2026: The CDC announced an overhaul of the childhood immunization schedule[23].
• April 2026: The CDC renewed the ACIP charter[6]. Over 130 organizations expressed concern about the revised charter[7].
• June 2026: The Pediatric Infectious Diseases Society warned that the new ACIP charter could threaten public access to vaccines[8].
• August 2026: President Trump issued an executive order to “break up the vaccine schedule into more doses”[5][19].
• October 2026: Measles cases in the U.S. reached 4,588, surpassing the 2025 total[14][21].

What changed and for whom

Federal childhood immunization recommendations faced significant attempted changes, though a federal judge blocked the implementation of some revisions[10][23]. The composition of the ACIP, a key advisory body, was completely overhauled, with many new members reportedly lacking extensive vaccine expertise[9]. These changes, along with shifts in official statements regarding vaccine safety, have generated concerns among over 130 medical and public health organizations about potentially undermining public confidence in vaccines and affecting access to immunizations[7][8][30].

The political landscape has also shown shifts. Former Republican lawmakers have expressed worry that the party's stance on vaccines could harm candidates in upcoming midterm elections[18]. Polling data indicated that Republican voters were three times more likely than Democrats to support ending vaccine requirements[2]. Research also pointed to widening health disparities, with conservatives more prone to vaccine avoidance[13]. Despite these trends, KFF polling in October 2026 showed broad trust in long-standing vaccines like MMR across political affiliations[20].

What the subject has said publicly

During his January 2025 confirmation hearings, Robert F. Kennedy Jr. told senators he fully supported the federal childhood immunization schedule and stated that all of his own children were vaccinated according to established guidelines[27]. However, a year into his term, reports indicated he had not upheld many of these promises[16]. In April 2026, Kennedy acknowledged that the measles, mumps, and rubella (MMR) vaccine is safe and effective “for most people” and that HHS promotes and recommends it for every child[4]. He also conceded that vaccination could possibly have saved a child's life during the Texas measles outbreak[4]. More recently, in September 2026, speaking at an anti-vaccine conference, Kennedy assured activists, “You have a strong and steadfast friend at the White House,” while acknowledging the need to navigate legal processes for significant policy changes[31].

What we could not confirm

We could not confirm the specific credentials or prior experience of each new appointee to the ACIP[9]. We could also not confirm the exact number of individuals directly impacted by the reduction in the federal childhood immunization schedule, given that a federal judge blocked its implementation[10][23].