Globally, the measles vaccine is estimated to have saved 21 million lives between 2000 and 2017, according to data cited by the Centers for Disease Control and Prevention in the United States. But there are still more than seven million cases and 100,000 deaths a year, the agency noted, many in developing countries where people lack access to the vaccine. Most who die are children younger than 5.
Even in developed countries, outbreaks have flared up in recent years as a growing number of parents have refused vaccination. Some claim religious reasons, and some mistakenly fear a link to autism, based on research that has been discredited as fraudulent.
Albania, Britain, the Czech Republic and Greece, which had declared measles eliminated, joined 12 other nations — including France, Germany, Poland, Romania and Russia — where the disease is now considered by the organization to be endemic.
Even in European countries where vaccination against measles is already required, including Bulgaria, France, Italy, Croatia, Czech Republic, Hungary, Latvia, Poland, Slovakia and Slovenia, the number of cases has been on the rise.
A measles vaccination involves two injections, the first usually given when children are 1 year old and the second when they are 4. The same shots (commonly referred to as the M.M.R. vaccine) include protection against mumps and rubella, and a newer version also protects against chickenpox.