Three hundred and twenty-one cases have been reported in the ongoing measles outbreak in Texas, New Mexico and Oklahoma, the states said Tuesday. This is an increase of 25 cases since an update on Friday.

As the measles outbreak that began in northwest Texas continues to spread, health officials are warning it could be months, and perhaps up to a year, before it’s declared over. The outbreak began in late January in the South Plains region shows no signs of slowing down,

The director of public health for the city of Lubbock said Tuesday that uptake of the measles vaccine “has definitely been a struggle,” and that the outbreak will be "large."