New York City Health Commissioner Oxiris Barbot on Tuesday warned parents in the city not to hold so-called "measles parties" as officials work to counter an outbreak of the disease. Barbot warned that some parents have had "measles parties" to have their children infected with the disease in an effort to immunize them naturally, rather than through a vaccination, according to BuzzFeed News. "We are concerned about families having measles parties," Barbot said at a news conference, according to Fox News.