U.S. older adults surge to measles immunity tests amid outbreaks

More than 74,000 U.S. adults over age 50 obtained measles antibody titer tests between January and March 2025. The testing spikes coincided with a West Texas measles outbreak and a later surge in South Carolina, which became the nation’s largest outbreak in decades.

Truveta, a health‑data analytics firm covering about one‑third of the U.S. population, analyzed medical records and found that heightened public awareness of local outbreaks appears to be driving the increase in testing. Nina Masters, Truveta’s principal applied research scientist and former CDC epidemiologist, said the pattern suggests Americans are seeking to confirm immunity to protect themselves and vulnerable family members.

The rise in testing occurs as the United States approaches a record year for measles cases, with the virus capable of lingering in indoor air for up to two hours after an infected person leaves, raising concerns for exposure in schools, churches, restaurants, stores and airports.