Some 250 immigrant children at a South Texas detention facility were recently given the wrong dose of a hepatitis A virus (HAV) vaccine, Fox News reports. Apparently, government health workers administered the adult dose of the shot to the kids, which is nearly twice as strong as the pediatric version.

U.S. Immigration and Customs Enforcement (ICE) officials are continuing to monitor the children for potential side effects from the HAV shot, but they don’t expect any complications. So far, none of the children has been hospitalized or showed any adverse reactions since being vaccinated.

The detention facility, located at the South Texas Family Residential Center in Dilley, holds nearly 2,000 women and children from Central America, who traveled to the United States via Mexico seeking asylum.

ICE remains confident that the hep A mix-up will not be dangerous to the children’s long-term health, but immigration advocates point out the mistake is further evidence of the poor health care immigrants receive at U.S. detention centers.