This is the tip of the iceberg,” said Rekha Lakshmanan, chief strategy officer for The Immunization Partnership in Houston, a nonprofit that advocates for vaccine access. “I think this is going to get a lot worse before it gets better.

The measles outbreak in Texas has escalated sharply to 90 cases as health officials worry about the spread to more communities.

A measles outbreak in Texas’ South Plains neared 100 cases Friday, according to the Texas Department of State Health Services, which warned more cases of the highly contagious virus are likely to pop up in outbreak areas.