The number of people with measles in Texas increased to 146 in an outbreak that led this week to the death of an unvaccinated school-aged child, health officials said Friday. The number of cases — Texas’ largest in nearly 30 years — increased by 22 since Tuesday.

Declining vaccination rates, decreasing trust in government and a political unwillingness to endorse vaccines is shaping Texas’ measles response.

A growing measles outbreak in Texas, where one unvaccinated child died and nearly 20 others have been hospitalized with serious complications, marks the first major test for U.S. Health Secretary Robert F.