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.

Rates of measles in the US have climbed significantly over the past 20 years, as vaccine skepticism has grown.

At least 124 cases have been reported since late January, mostly among children and teenagers who were unvaccinated or whose vaccination status was unknown.