US Measles Outbreak Spreads: 2026 Cases Exceed Half of 2025 Total, Colorado & Massachusetts Exposures

The United States is grappling with a widespread measles outbreak, with over 1,100 cases reported in the first two months of 2026. This rapid increase has alarmed public health officials, raising concerns about potential deaths and the strain on healthcare systems. The resurgence of measles is largely attributed to declining MMR vaccination rates among children, falling below the 95% threshold needed for herd immunity in many areas. This has left a significant portion of the population vulnerable to the highly contagious virus. The CDC reports that in 2025 there were 2,600 cases across 44 states, and 49 distinct measles outbreaks resulted in the deaths of three children, marking the first deaths from the virus since 2015. ## Latest Update Colorado health officials have identified 11 possible exposure sites linked to the outbreak, including two schools, three restaurants, and a grocery store. Massachusetts has also reported two measles cases, the state's first since 2024, one in Greater Boston and another in an unspecifed region of the Commonwealth. ## Timeline * **2026-02-10:** The CDC reports nearly 2,000 measles cases in 2025 across the US, with significant outbreaks in South Carolina, Utah, and Arizona, and the first case in Connecticut since 2021. * **2026-02-14:** Experts highlight declining immunization rates and urge vaccination as measles cases surge to over 2,600 across 44 states in 2025, with 8 cases confirmed in Allen County, Indiana. * **2026-02-24:** Health systems in the Carolinas struggle with a lack of experience treating measles as the outbreak intensifies, reaching approximately 1,000 cases. * **2026-02-27:** Measles cases in early 2026 surpass half of the total cases seen in all of 2025. * **2026-02-27:** The US surpasses 1,100 measles cases in two months, raising concerns about future deaths. * **2026-02-27:** Massachusetts reports two measles cases, the first since 2024, including one in Greater Boston. * **2026-03-05:** Colorado identifies 11 possible exposure sites, including schools, restaurants, and a grocery store, linked to the measles outbreak. * **2026-03-07:** Colorado officials conduct contact tracing at two schools following measles exposures. ## What to Watch * **Further Spread:** Monitor for new cases and exposure locations in affected states and neighboring regions. * **Vaccination Rates:** Track vaccination rates and public health campaigns aimed at increasing MMR coverage. * **Healthcare Strain:** Observe the impact on healthcare systems, particularly in areas with large outbreaks, and potential resource shortages.