Israel is dealing with one of its worst measles outbreaks in decades, reports the Washington Post.

In Israel, several ultra-Orthodox Jewish sects oppose vaccination, and the Health Ministry has stepped up a campaign to increase vaccination rates in unprotected communities in recent months.

Israeli media reported Thursday that an 18-month-old baby died of complications of the disease at a Jerusalem hospital, the country’s first death from measles since 2003. The child was not vaccinated.